--- a/memory/build/mozjemalloc.cpp
+++ b/memory/build/mozjemalloc.cpp
@@ -1,187 +1,184 @@
/* -*- Mode: C; tab-width: 8; c-basic-offset: 8; indent-tabs-mode: t -*- */
/* vim:set softtabstop=8 shiftwidth=8 noet: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-/*
- * Portions of this file were originally under the following license:
- *
- * Copyright (C) 2006-2008 Jason Evans <jasone@FreeBSD.org>.
- * All rights reserved.
- * Copyright (C) 2007-2017 Mozilla Foundation.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice(s), this list of conditions and the following disclaimer as
- * the first lines of this file unmodified other than the possible
- * addition of one or more copyright notices.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice(s), this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
- * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
- * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
- * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- *******************************************************************************
- *
- * This allocator implementation is designed to provide scalable performance
- * for multi-threaded programs on multi-processor systems. The following
- * features are included for this purpose:
- *
- * + Multiple arenas are used if there are multiple CPUs, which reduces lock
- * contention and cache sloshing.
- *
- * + Cache line sharing between arenas is avoided for internal data
- * structures.
- *
- * + Memory is managed in chunks and runs (chunks can be split into runs),
- * rather than as individual pages. This provides a constant-time
- * mechanism for associating allocations with particular arenas.
- *
- * Allocation requests are rounded up to the nearest size class, and no record
- * of the original request size is maintained. Allocations are broken into
- * categories according to size class. Assuming runtime defaults, 4 kB pages
- * and a 16 byte quantum on a 32-bit system, the size classes in each category
- * are as follows:
- *
- * |=====================================|
- * | Category | Subcategory | Size |
- * |=====================================|
- * | Small | Tiny | 2 |
- * | | | 4 |
- * | | | 8 |
- * | |----------------+---------|
- * | | Quantum-spaced | 16 |
- * | | | 32 |
- * | | | 48 |
- * | | | ... |
- * | | | 480 |
- * | | | 496 |
- * | | | 512 |
- * | |----------------+---------|
- * | | Sub-page | 1 kB |
- * | | | 2 kB |
- * |=====================================|
- * | Large | 4 kB |
- * | | 8 kB |
- * | | 12 kB |
- * | | ... |
- * | | 1012 kB |
- * | | 1016 kB |
- * | | 1020 kB |
- * |=====================================|
- * | Huge | 1 MB |
- * | | 2 MB |
- * | | 3 MB |
- * | | ... |
- * |=====================================|
- *
- * NOTE: Due to Mozilla bug 691003, we cannot reserve less than one word for an
- * allocation on Linux or Mac. So on 32-bit *nix, the smallest bucket size is
- * 4 bytes, and on 64-bit, the smallest bucket size is 8 bytes.
- *
- * A different mechanism is used for each category:
- *
- * Small : Each size class is segregated into its own set of runs. Each run
- * maintains a bitmap of which regions are free/allocated.
- *
- * Large : Each allocation is backed by a dedicated run. Metadata are stored
- * in the associated arena chunk header maps.
- *
- * Huge : Each allocation is backed by a dedicated contiguous set of chunks.
- * Metadata are stored in a separate red-black tree.
- *
- *******************************************************************************
- */
+// Portions of this file were originally under the following license:
+//
+// Copyright (C) 2006-2008 Jason Evans <jasone@FreeBSD.org>.
+// All rights reserved.
+// Copyright (C) 2007-2017 Mozilla Foundation.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions
+// are met:
+// 1. Redistributions of source code must retain the above copyright
+// notice(s), this list of conditions and the following disclaimer as
+// the first lines of this file unmodified other than the possible
+// addition of one or more copyright notices.
+// 2. Redistributions in binary form must reproduce the above copyright
+// notice(s), this list of conditions and the following disclaimer in
+// the documentation and/or other materials provided with the
+// distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+// OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// *****************************************************************************
+//
+// This allocator implementation is designed to provide scalable performance
+// for multi-threaded programs on multi-processor systems. The following
+// features are included for this purpose:
+//
+// + Multiple arenas are used if there are multiple CPUs, which reduces lock
+// contention and cache sloshing.
+//
+// + Cache line sharing between arenas is avoided for internal data
+// structures.
+//
+// + Memory is managed in chunks and runs (chunks can be split into runs),
+// rather than as individual pages. This provides a constant-time
+// mechanism for associating allocations with particular arenas.
+//
+// Allocation requests are rounded up to the nearest size class, and no record
+// of the original request size is maintained. Allocations are broken into
+// categories according to size class. Assuming runtime defaults, 4 kB pages
+// and a 16 byte quantum on a 32-bit system, the size classes in each category
+// are as follows:
+//
+// |=====================================|
+// | Category | Subcategory | Size |
+// |=====================================|
+// | Small | Tiny | 2 |
+// | | | 4 |
+// | | | 8 |
+// | |----------------+---------|
+// | | Quantum-spaced | 16 |
+// | | | 32 |
+// | | | 48 |
+// | | | ... |
+// | | | 480 |
+// | | | 496 |
+// | | | 512 |
+// | |----------------+---------|
+// | | Sub-page | 1 kB |
+// | | | 2 kB |
+// |=====================================|
+// | Large | 4 kB |
+// | | 8 kB |
+// | | 12 kB |
+// | | ... |
+// | | 1012 kB |
+// | | 1016 kB |
+// | | 1020 kB |
+// |=====================================|
+// | Huge | 1 MB |
+// | | 2 MB |
+// | | 3 MB |
+// | | ... |
+// |=====================================|
+//
+// NOTE: Due to Mozilla bug 691003, we cannot reserve less than one word for an
+// allocation on Linux or Mac. So on 32-bit *nix, the smallest bucket size is
+// 4 bytes, and on 64-bit, the smallest bucket size is 8 bytes.
+//
+// A different mechanism is used for each category:
+//
+// Small : Each size class is segregated into its own set of runs. Each run
+// maintains a bitmap of which regions are free/allocated.
+//
+// Large : Each allocation is backed by a dedicated run. Metadata are stored
+// in the associated arena chunk header maps.
+//
+// Huge : Each allocation is backed by a dedicated contiguous set of chunks.
+// Metadata are stored in a separate red-black tree.
+//
+// *****************************************************************************
#include "mozmemory_wrap.h"
#include "mozjemalloc.h"
#include "mozilla/Atomics.h"
#include "mozilla/DoublyLinkedList.h"
#include "mozilla/GuardObjects.h"
#include "mozilla/Likely.h"
#include "mozilla/Sprintf.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/Unused.h"
-/*
- * On Linux, we use madvise(MADV_DONTNEED) to release memory back to the
- * operating system. If we release 1MB of live pages with MADV_DONTNEED, our
- * RSS will decrease by 1MB (almost) immediately.
- *
- * On Mac, we use madvise(MADV_FREE). Unlike MADV_DONTNEED on Linux, MADV_FREE
- * on Mac doesn't cause the OS to release the specified pages immediately; the
- * OS keeps them in our process until the machine comes under memory pressure.
- *
- * It's therefore difficult to measure the process's RSS on Mac, since, in the
- * absence of memory pressure, the contribution from the heap to RSS will not
- * decrease due to our madvise calls.
- *
- * We therefore define MALLOC_DOUBLE_PURGE on Mac. This causes jemalloc to
- * track which pages have been MADV_FREE'd. You can then call
- * jemalloc_purge_freed_pages(), which will force the OS to release those
- * MADV_FREE'd pages, making the process's RSS reflect its true memory usage.
- *
- * The jemalloc_purge_freed_pages definition in memory/build/mozmemory.h needs
- * to be adjusted if MALLOC_DOUBLE_PURGE is ever enabled on Linux.
- */
+// On Linux, we use madvise(MADV_DONTNEED) to release memory back to the
+// operating system. If we release 1MB of live pages with MADV_DONTNEED, our
+// RSS will decrease by 1MB (almost) immediately.
+//
+// On Mac, we use madvise(MADV_FREE). Unlike MADV_DONTNEED on Linux, MADV_FREE
+// on Mac doesn't cause the OS to release the specified pages immediately; the
+// OS keeps them in our process until the machine comes under memory pressure.
+//
+// It's therefore difficult to measure the process's RSS on Mac, since, in the
+// absence of memory pressure, the contribution from the heap to RSS will not
+// decrease due to our madvise calls.
+//
+// We therefore define MALLOC_DOUBLE_PURGE on Mac. This causes jemalloc to
+// track which pages have been MADV_FREE'd. You can then call
+// jemalloc_purge_freed_pages(), which will force the OS to release those
+// MADV_FREE'd pages, making the process's RSS reflect its true memory usage.
+//
+// The jemalloc_purge_freed_pages definition in memory/build/mozmemory.h needs
+// to be adjusted if MALLOC_DOUBLE_PURGE is ever enabled on Linux.
+
#ifdef XP_DARWIN
#define MALLOC_DOUBLE_PURGE
#endif
#include <sys/types.h>
#include <errno.h>
#include <stdlib.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <algorithm>
#ifdef XP_WIN
-/* Some defines from the CRT internal headers that we need here. */
+// Some defines from the CRT internal headers that we need here.
#define _CRT_SPINCOUNT 5000
#include <io.h>
#include <windows.h>
#include <intrin.h>
#define SIZE_T_MAX SIZE_MAX
#define STDERR_FILENO 2
-/* use MSVC intrinsics */
+// Use MSVC intrinsics.
#pragma intrinsic(_BitScanForward)
static __forceinline int
ffs(int x)
{
unsigned long i;
if (_BitScanForward(&i, x) != 0) {
return i + 1;
}
return 0;
}
-/* Implement getenv without using malloc */
+// Implement getenv without using malloc.
static char mozillaMallocOptionsBuf[64];
#define getenv xgetenv
static char *
getenv(const char *name)
{
if (GetEnvironmentVariableA(name, mozillaMallocOptionsBuf,
@@ -246,265 +243,241 @@ typedef long ssize_t;
#include <malloc/malloc.h>
#endif
#endif
#include "mozilla/ThreadLocal.h"
#include "mozjemalloc_types.h"
-/* Some tools, such as /dev/dsp wrappers, LD_PRELOAD libraries that
- * happen to override mmap() and call dlsym() from their overridden
- * mmap(). The problem is that dlsym() calls malloc(), and this ends
- * up in a dead lock in jemalloc.
- * On these systems, we prefer to directly use the system call.
- * We do that for Linux systems and kfreebsd with GNU userland.
- * Note sanity checks are not done (alignment of offset, ...) because
- * the uses of mmap are pretty limited, in jemalloc.
- *
- * On Alpha, glibc has a bug that prevents syscall() to work for system
- * calls with 6 arguments
- */
+// Some tools, such as /dev/dsp wrappers, LD_PRELOAD libraries that
+// happen to override mmap() and call dlsym() from their overridden
+// mmap(). The problem is that dlsym() calls malloc(), and this ends
+// up in a dead lock in jemalloc.
+// On these systems, we prefer to directly use the system call.
+// We do that for Linux systems and kfreebsd with GNU userland.
+// Note sanity checks are not done (alignment of offset, ...) because
+// the uses of mmap are pretty limited, in jemalloc.
+//
+// On Alpha, glibc has a bug that prevents syscall() to work for system
+// calls with 6 arguments.
#if (defined(XP_LINUX) && !defined(__alpha__)) || \
(defined(__FreeBSD_kernel__) && defined(__GLIBC__))
#include <sys/syscall.h>
#if defined(SYS_mmap) || defined(SYS_mmap2)
static inline
void *_mmap(void *addr, size_t length, int prot, int flags,
int fd, off_t offset)
{
-/* S390 only passes one argument to the mmap system call, which is a
- * pointer to a structure containing the arguments */
+// S390 only passes one argument to the mmap system call, which is a
+// pointer to a structure containing the arguments.
#ifdef __s390__
struct {
void *addr;
size_t length;
long prot;
long flags;
long fd;
off_t offset;
} args = { addr, length, prot, flags, fd, offset };
return (void *) syscall(SYS_mmap, &args);
#else
#if defined(ANDROID) && defined(__aarch64__) && defined(SYS_mmap2)
-/* Android NDK defines SYS_mmap2 for AArch64 despite it not supporting mmap2 */
+// Android NDK defines SYS_mmap2 for AArch64 despite it not supporting mmap2.
#undef SYS_mmap2
#endif
#ifdef SYS_mmap2
return (void *) syscall(SYS_mmap2, addr, length, prot, flags,
fd, offset >> 12);
#else
return (void *) syscall(SYS_mmap, addr, length, prot, flags,
fd, offset);
#endif
#endif
}
#define mmap _mmap
#define munmap(a, l) syscall(SYS_munmap, a, l)
#endif
#endif
-/* Size of stack-allocated buffer passed to strerror_r(). */
+// Size of stack-allocated buffer passed to strerror_r().
#define STRERROR_BUF 64
-/* Minimum alignment of non-tiny allocations is 2^QUANTUM_2POW_MIN bytes. */
+// Minimum alignment of non-tiny allocations is 2^QUANTUM_2POW_MIN bytes.
# define QUANTUM_2POW_MIN 4
#if defined(_WIN64) || defined(__LP64__)
# define SIZEOF_PTR_2POW 3
#else
# define SIZEOF_PTR_2POW 2
#endif
#define SIZEOF_PTR (1U << SIZEOF_PTR_2POW)
#include "rb.h"
-/* sizeof(int) == (1U << SIZEOF_INT_2POW). */
+// sizeof(int) == (1U << SIZEOF_INT_2POW).
#ifndef SIZEOF_INT_2POW
# define SIZEOF_INT_2POW 2
#endif
-/*
- * Size and alignment of memory chunks that are allocated by the OS's virtual
- * memory system.
- */
+// Size and alignment of memory chunks that are allocated by the OS's virtual
+// memory system.
#define CHUNK_2POW_DEFAULT 20
-/* Maximum number of dirty pages per arena. */
+// Maximum number of dirty pages per arena.
#define DIRTY_MAX_DEFAULT (1U << 8)
-/*
- * Maximum size of L1 cache line. This is used to avoid cache line aliasing,
- * so over-estimates are okay (up to a point), but under-estimates will
- * negatively affect performance.
- */
+// Maximum size of L1 cache line. This is used to avoid cache line aliasing,
+// so over-estimates are okay (up to a point), but under-estimates will
+// negatively affect performance.
#define CACHELINE_2POW 6
#define CACHELINE ((size_t)(1U << CACHELINE_2POW))
-/*
- * Smallest size class to support. On Windows the smallest allocation size
- * must be 8 bytes on 32-bit, 16 bytes on 64-bit. On Linux and Mac, even
- * malloc(1) must reserve a word's worth of memory (see Mozilla bug 691003).
- */
+// Smallest size class to support. On Windows the smallest allocation size
+// must be 8 bytes on 32-bit, 16 bytes on 64-bit. On Linux and Mac, even
+// malloc(1) must reserve a word's worth of memory (see Mozilla bug 691003).
#ifdef XP_WIN
#define TINY_MIN_2POW (sizeof(void*) == 8 ? 4 : 3)
#else
#define TINY_MIN_2POW (sizeof(void*) == 8 ? 3 : 2)
#endif
-/*
- * Maximum size class that is a multiple of the quantum, but not (necessarily)
- * a power of 2. Above this size, allocations are rounded up to the nearest
- * power of 2.
- */
+// Maximum size class that is a multiple of the quantum, but not (necessarily)
+// a power of 2. Above this size, allocations are rounded up to the nearest
+// power of 2.
#define SMALL_MAX_2POW_DEFAULT 9
#define SMALL_MAX_DEFAULT (1U << SMALL_MAX_2POW_DEFAULT)
-/*
- * RUN_MAX_OVRHD indicates maximum desired run header overhead. Runs are sized
- * as small as possible such that this setting is still honored, without
- * violating other constraints. The goal is to make runs as small as possible
- * without exceeding a per run external fragmentation threshold.
- *
- * We use binary fixed point math for overhead computations, where the binary
- * point is implicitly RUN_BFP bits to the left.
- *
- * Note that it is possible to set RUN_MAX_OVRHD low enough that it cannot be
- * honored for some/all object sizes, since there is one bit of header overhead
- * per object (plus a constant). This constraint is relaxed (ignored) for runs
- * that are so small that the per-region overhead is greater than:
- *
- * (RUN_MAX_OVRHD / (reg_size << (3+RUN_BFP))
- */
+// RUN_MAX_OVRHD indicates maximum desired run header overhead. Runs are sized
+// as small as possible such that this setting is still honored, without
+// violating other constraints. The goal is to make runs as small as possible
+// without exceeding a per run external fragmentation threshold.
+//
+// We use binary fixed point math for overhead computations, where the binary
+// point is implicitly RUN_BFP bits to the left.
+//
+// Note that it is possible to set RUN_MAX_OVRHD low enough that it cannot be
+// honored for some/all object sizes, since there is one bit of header overhead
+// per object (plus a constant). This constraint is relaxed (ignored) for runs
+// that are so small that the per-region overhead is greater than:
+//
+// (RUN_MAX_OVRHD / (reg_size << (3+RUN_BFP))
#define RUN_BFP 12
-/* \/ Implicit binary fixed point. */
+// \/ Implicit binary fixed point.
#define RUN_MAX_OVRHD 0x0000003dU
#define RUN_MAX_OVRHD_RELAX 0x00001800U
-/*
- * When MALLOC_STATIC_PAGESIZE is defined, the page size is fixed at
- * compile-time for better performance, as opposed to determined at
- * runtime. Some platforms can have different page sizes at runtime
- * depending on kernel configuration, so they are opted out by default.
- * Debug builds are opted out too, for test coverage.
- */
+// When MALLOC_STATIC_PAGESIZE is defined, the page size is fixed at
+// compile-time for better performance, as opposed to determined at
+// runtime. Some platforms can have different page sizes at runtime
+// depending on kernel configuration, so they are opted out by default.
+// Debug builds are opted out too, for test coverage.
#ifndef MOZ_DEBUG
#if !defined(__ia64__) && !defined(__sparc__) && !defined(__mips__) && !defined(__aarch64__)
#define MALLOC_STATIC_PAGESIZE 1
#endif
#endif
-/* Various quantum-related settings. */
-
+// Various quantum-related settings.
#define QUANTUM_DEFAULT (size_t(1) << QUANTUM_2POW_MIN)
static const size_t quantum = QUANTUM_DEFAULT;
static const size_t quantum_mask = QUANTUM_DEFAULT - 1;
-/* Various bin-related settings. */
-
+// Various bin-related settings.
static const size_t small_min = (QUANTUM_DEFAULT >> 1) + 1;
static const size_t small_max = size_t(SMALL_MAX_DEFAULT);
-/* Number of (2^n)-spaced tiny bins. */
+// Number of (2^n)-spaced tiny bins.
static const unsigned ntbins = unsigned(QUANTUM_2POW_MIN - TINY_MIN_2POW);
- /* Number of quantum-spaced bins. */
+// Number of quantum-spaced bins.
static const unsigned nqbins = unsigned(SMALL_MAX_DEFAULT >> QUANTUM_2POW_MIN);
#ifdef MALLOC_STATIC_PAGESIZE
-/*
- * VM page size. It must divide the runtime CPU page size or the code
- * will abort.
- * Platform specific page size conditions copied from js/public/HeapAPI.h
- */
+// VM page size. It must divide the runtime CPU page size or the code
+// will abort.
+// Platform specific page size conditions copied from js/public/HeapAPI.h
#if (defined(SOLARIS) || defined(__FreeBSD__)) && \
(defined(__sparc) || defined(__sparcv9) || defined(__ia64))
#define pagesize_2pow (size_t(13))
#elif defined(__powerpc64__)
#define pagesize_2pow (size_t(16))
#else
#define pagesize_2pow (size_t(12))
#endif
#define pagesize (size_t(1) << pagesize_2pow)
#define pagesize_mask (pagesize - 1)
-/* Max size class for bins. */
+// Max size class for bins.
static const size_t bin_maxclass = pagesize >> 1;
-/* Number of (2^n)-spaced sub-page bins. */
+// Number of (2^n)-spaced sub-page bins.
static const unsigned nsbins = unsigned(pagesize_2pow - SMALL_MAX_2POW_DEFAULT - 1);
-#else /* !MALLOC_STATIC_PAGESIZE */
-
-/* VM page size. */
+#else // !MALLOC_STATIC_PAGESIZE
+
+// VM page size.
static size_t pagesize;
static size_t pagesize_mask;
static size_t pagesize_2pow;
-/* Various bin-related settings. */
-static size_t bin_maxclass; /* Max size class for bins. */
-static unsigned nsbins; /* Number of (2^n)-spaced sub-page bins. */
+// Various bin-related settings.
+static size_t bin_maxclass; // Max size class for bins.
+static unsigned nsbins; // Number of (2^n)-spaced sub-page bins.
#endif
-/* Various chunk-related settings. */
-
-/*
- * Compute the header size such that it is large enough to contain the page map
- * and enough nodes for the worst case: one node per non-header page plus one
- * extra for situations where we briefly have one more node allocated than we
- * will need.
- */
+// Various chunk-related settings.
+
+// Compute the header size such that it is large enough to contain the page map
+// and enough nodes for the worst case: one node per non-header page plus one
+// extra for situations where we briefly have one more node allocated than we
+// will need.
#define calculate_arena_header_size() \
(sizeof(arena_chunk_t) + sizeof(arena_chunk_map_t) * (chunk_npages - 1))
#define calculate_arena_header_pages() \
((calculate_arena_header_size() >> pagesize_2pow) + \
((calculate_arena_header_size() & pagesize_mask) ? 1 : 0))
-/* Max size class for arenas. */
+// Max size class for arenas.
#define calculate_arena_maxclass() \
(chunksize - (arena_chunk_header_npages << pagesize_2pow))
#define CHUNKSIZE_DEFAULT ((size_t) 1 << CHUNK_2POW_DEFAULT)
static const size_t chunksize = CHUNKSIZE_DEFAULT;
static const size_t chunksize_mask = CHUNKSIZE_DEFAULT - 1;
#ifdef MALLOC_STATIC_PAGESIZE
static const size_t chunk_npages = CHUNKSIZE_DEFAULT >> pagesize_2pow;
#define arena_chunk_header_npages calculate_arena_header_pages()
#define arena_maxclass calculate_arena_maxclass()
#else
static size_t chunk_npages;
static size_t arena_chunk_header_npages;
-static size_t arena_maxclass; /* Max size class for arenas. */
+static size_t arena_maxclass; // Max size class for arenas.
#endif
-/*
- * Recycle at most 128 chunks. With 1 MiB chunks, this means we retain at most
- * 6.25% of the process address space on a 32-bit OS for later use.
- */
+// Recycle at most 128 chunks. With 1 MiB chunks, this means we retain at most
+// 6.25% of the process address space on a 32-bit OS for later use.
#define CHUNK_RECYCLE_LIMIT 128
static const size_t gRecycleLimit = CHUNK_RECYCLE_LIMIT * CHUNKSIZE_DEFAULT;
-/* The current amount of recycled bytes, updated atomically. */
+// The current amount of recycled bytes, updated atomically.
static mozilla::Atomic<size_t, mozilla::ReleaseAcquire> gRecycledSize;
-/******************************************************************************/
-
-/* MALLOC_DECOMMIT and MALLOC_DOUBLE_PURGE are mutually exclusive. */
+// ***************************************************************************
+// MALLOC_DECOMMIT and MALLOC_DOUBLE_PURGE are mutually exclusive.
#if defined(MALLOC_DECOMMIT) && defined(MALLOC_DOUBLE_PURGE)
#error MALLOC_DECOMMIT and MALLOC_DOUBLE_PURGE are mutually exclusive.
#endif
-/*
- * Mutexes based on spinlocks. We can't use normal pthread spinlocks in all
- * places, because they require malloc()ed memory, which causes bootstrapping
- * issues in some cases.
- */
+// Mutexes based on spinlocks. We can't use normal pthread spinlocks in all
+// places, because they require malloc()ed memory, which causes bootstrapping
+// issues in some cases.
struct Mutex
{
#if defined(XP_WIN)
CRITICAL_SECTION mMutex;
#elif defined(XP_DARWIN)
OSSpinLock mMutex;
#else
pthread_mutex_t mMutex;
@@ -528,80 +501,76 @@ struct MOZ_RAII MutexAutoLock
~MutexAutoLock() { mMutex.Unlock(); }
private:
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER;
Mutex& mMutex;
};
-/* Set to true once the allocator has been initialized. */
+// Set to true once the allocator has been initialized.
static bool malloc_initialized = false;
#if defined(XP_WIN)
-/* No init lock for Windows. */
+// No init lock for Windows.
#elif defined(XP_DARWIN)
static Mutex gInitLock = { OS_SPINLOCK_INIT };
#elif defined(XP_LINUX) && !defined(ANDROID)
static Mutex gInitLock = { PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP };
#else
static Mutex gInitLock = { PTHREAD_MUTEX_INITIALIZER };
#endif
-/******************************************************************************/
-/*
- * Statistics data structures.
- */
+// ***************************************************************************
+// Statistics data structures.
struct malloc_bin_stats_t {
- /* Current number of runs in this bin. */
+ // Current number of runs in this bin.
unsigned long curruns;
};
struct arena_stats_t {
- /* Number of bytes currently mapped. */
+ // Number of bytes currently mapped.
size_t mapped;
- /* Current number of committed pages. */
+ // Current number of committed pages.
size_t committed;
- /* Per-size-category statistics. */
+ // Per-size-category statistics.
size_t allocated_small;
size_t allocated_large;
};
-/******************************************************************************/
-/*
- * Extent data structures.
- */
+// ***************************************************************************
+// Extent data structures.
enum ChunkType {
UNKNOWN_CHUNK,
- ZEROED_CHUNK, // chunk only contains zeroes
- ARENA_CHUNK, // used to back arena runs created by arena_t::AllocRun
- HUGE_CHUNK, // used to back huge allocations (e.g. huge_malloc)
- RECYCLED_CHUNK, // chunk has been stored for future use by chunk_recycle
+ ZEROED_CHUNK, // chunk only contains zeroes.
+ ARENA_CHUNK, // used to back arena runs created by arena_t::AllocRun.
+ HUGE_CHUNK, // used to back huge allocations (e.g. huge_malloc).
+ RECYCLED_CHUNK, // chunk has been stored for future use by chunk_recycle.
};
-/* Tree of extents. */
+// Tree of extents.
struct extent_node_t {
- /* Linkage for the size/address-ordered tree. */
+ // Linkage for the size/address-ordered tree.
RedBlackTreeNode<extent_node_t> link_szad;
- /* Linkage for the address-ordered tree. */
+ // Linkage for the address-ordered tree.
RedBlackTreeNode<extent_node_t> link_ad;
- /* Pointer to the extent that this tree node is responsible for. */
+ // Pointer to the extent that this tree node is responsible for.
void *addr;
- /* Total region size. */
+ // Total region size.
size_t size;
- /* What type of chunk is there; used by chunk recycling code. */
+ // What type of chunk is there; used by chunk recycling code.
ChunkType chunk_type;
};
template<typename T>
int
CompareAddr(T* aAddr1, T* aAddr2)
{
uintptr_t addr1 = reinterpret_cast<uintptr_t>(aAddr1);
@@ -649,32 +618,29 @@ struct ExtentTreeBoundsTrait : public Ex
if (node_addr <= key_addr && key_addr < node_addr + node_size) {
return 0;
}
return (key_addr > node_addr) - (key_addr < node_addr);
}
};
-/******************************************************************************/
-/*
- * Radix tree data structures.
- *
- * The number of bits passed to the template is the number of significant bits
- * in an address to do a radix lookup with.
- *
- * An address is looked up by splitting it in kBitsPerLevel bit chunks, except
- * the most significant bits, where the bit chunk is kBitsAtLevel1 which can be
- * different if Bits is not a multiple of kBitsPerLevel.
- *
- * With e.g. sizeof(void*)=4, Bits=16 and kBitsPerLevel=8, an address is split
- * like the following:
- * 0x12345678 -> mRoot[0x12][0x34]
- */
-
+// ***************************************************************************
+// Radix tree data structures.
+//
+// The number of bits passed to the template is the number of significant bits
+// in an address to do a radix lookup with.
+//
+// An address is looked up by splitting it in kBitsPerLevel bit chunks, except
+// the most significant bits, where the bit chunk is kBitsAtLevel1 which can be
+// different if Bits is not a multiple of kBitsPerLevel.
+//
+// With e.g. sizeof(void*)=4, Bits=16 and kBitsPerLevel=8, an address is split
+// like the following:
+// 0x12345678 -> mRoot[0x12][0x34]
template <size_t Bits>
class AddressRadixTree {
// Size of each radix tree node (as a power of 2).
// This impacts tree depth.
#if (SIZEOF_PTR == 4)
static const size_t kNodeSize2Pow = 14;
#else
static const size_t kNodeSize2Pow = CACHELINE_2POW;
@@ -689,116 +655,110 @@ class AddressRadixTree {
Mutex mLock;
void** mRoot;
public:
bool Init();
inline void* Get(void* aAddr);
- // Returns whether the value was properly set
+ // Returns whether the value was properly set.
inline bool Set(void* aAddr, void* aValue);
inline bool Unset(void* aAddr)
{
return Set(aAddr, nullptr);
}
private:
inline void** GetSlot(void* aAddr, bool aCreate = false);
};
-/******************************************************************************/
-/*
- * Arena data structures.
- */
+// ***************************************************************************
+// Arena data structures.
struct arena_t;
struct arena_bin_t;
-/* Each element of the chunk map corresponds to one page within the chunk. */
+// Each element of the chunk map corresponds to one page within the chunk.
struct arena_chunk_map_t {
- /*
- * Linkage for run trees. There are two disjoint uses:
- *
- * 1) arena_t's tree or available runs.
- * 2) arena_run_t conceptually uses this linkage for in-use non-full
- * runs, rather than directly embedding linkage.
- */
+ // Linkage for run trees. There are two disjoint uses:
+ //
+ // 1) arena_t's tree or available runs.
+ // 2) arena_run_t conceptually uses this linkage for in-use non-full
+ // runs, rather than directly embedding linkage.
RedBlackTreeNode<arena_chunk_map_t> link;
- /*
- * Run address (or size) and various flags are stored together. The bit
- * layout looks like (assuming 32-bit system):
- *
- * ???????? ???????? ????---- -mckdzla
- *
- * ? : Unallocated: Run address for first/last pages, unset for internal
- * pages.
- * Small: Run address.
- * Large: Run size for first page, unset for trailing pages.
- * - : Unused.
- * m : MADV_FREE/MADV_DONTNEED'ed?
- * c : decommitted?
- * k : key?
- * d : dirty?
- * z : zeroed?
- * l : large?
- * a : allocated?
- *
- * Following are example bit patterns for the three types of runs.
- *
- * r : run address
- * s : run size
- * x : don't care
- * - : 0
- * [cdzla] : bit set
- *
- * Unallocated:
- * ssssssss ssssssss ssss---- --c-----
- * xxxxxxxx xxxxxxxx xxxx---- ----d---
- * ssssssss ssssssss ssss---- -----z--
- *
- * Small:
- * rrrrrrrr rrrrrrrr rrrr---- -------a
- * rrrrrrrr rrrrrrrr rrrr---- -------a
- * rrrrrrrr rrrrrrrr rrrr---- -------a
- *
- * Large:
- * ssssssss ssssssss ssss---- ------la
- * -------- -------- -------- ------la
- * -------- -------- -------- ------la
- */
+ // Run address (or size) and various flags are stored together. The bit
+ // layout looks like (assuming 32-bit system):
+ //
+ // ???????? ???????? ????---- -mckdzla
+ //
+ // ? : Unallocated: Run address for first/last pages, unset for internal
+ // pages.
+ // Small: Run address.
+ // Large: Run size for first page, unset for trailing pages.
+ // - : Unused.
+ // m : MADV_FREE/MADV_DONTNEED'ed?
+ // c : decommitted?
+ // k : key?
+ // d : dirty?
+ // z : zeroed?
+ // l : large?
+ // a : allocated?
+ //
+ // Following are example bit patterns for the three types of runs.
+ //
+ // r : run address
+ // s : run size
+ // x : don't care
+ // - : 0
+ // [cdzla] : bit set
+ //
+ // Unallocated:
+ // ssssssss ssssssss ssss---- --c-----
+ // xxxxxxxx xxxxxxxx xxxx---- ----d---
+ // ssssssss ssssssss ssss---- -----z--
+ //
+ // Small:
+ // rrrrrrrr rrrrrrrr rrrr---- -------a
+ // rrrrrrrr rrrrrrrr rrrr---- -------a
+ // rrrrrrrr rrrrrrrr rrrr---- -------a
+ //
+ // Large:
+ // ssssssss ssssssss ssss---- ------la
+ // -------- -------- -------- ------la
+ // -------- -------- -------- ------la
size_t bits;
-/* Note that CHUNK_MAP_DECOMMITTED's meaning varies depending on whether
- * MALLOC_DECOMMIT and MALLOC_DOUBLE_PURGE are defined.
- *
- * If MALLOC_DECOMMIT is defined, a page which is CHUNK_MAP_DECOMMITTED must be
- * re-committed with pages_commit() before it may be touched. If
- * MALLOC_DECOMMIT is defined, MALLOC_DOUBLE_PURGE may not be defined.
- *
- * If neither MALLOC_DECOMMIT nor MALLOC_DOUBLE_PURGE is defined, pages which
- * are madvised (with either MADV_DONTNEED or MADV_FREE) are marked with
- * CHUNK_MAP_MADVISED.
- *
- * Otherwise, if MALLOC_DECOMMIT is not defined and MALLOC_DOUBLE_PURGE is
- * defined, then a page which is madvised is marked as CHUNK_MAP_MADVISED.
- * When it's finally freed with jemalloc_purge_freed_pages, the page is marked
- * as CHUNK_MAP_DECOMMITTED.
- */
+// Note that CHUNK_MAP_DECOMMITTED's meaning varies depending on whether
+// MALLOC_DECOMMIT and MALLOC_DOUBLE_PURGE are defined.
+//
+// If MALLOC_DECOMMIT is defined, a page which is CHUNK_MAP_DECOMMITTED must be
+// re-committed with pages_commit() before it may be touched. If
+// MALLOC_DECOMMIT is defined, MALLOC_DOUBLE_PURGE may not be defined.
+//
+// If neither MALLOC_DECOMMIT nor MALLOC_DOUBLE_PURGE is defined, pages which
+// are madvised (with either MADV_DONTNEED or MADV_FREE) are marked with
+// CHUNK_MAP_MADVISED.
+//
+// Otherwise, if MALLOC_DECOMMIT is not defined and MALLOC_DOUBLE_PURGE is
+// defined, then a page which is madvised is marked as CHUNK_MAP_MADVISED.
+// When it's finally freed with jemalloc_purge_freed_pages, the page is marked
+// as CHUNK_MAP_DECOMMITTED.
#define CHUNK_MAP_MADVISED ((size_t)0x40U)
#define CHUNK_MAP_DECOMMITTED ((size_t)0x20U)
#define CHUNK_MAP_MADVISED_OR_DECOMMITTED (CHUNK_MAP_MADVISED | CHUNK_MAP_DECOMMITTED)
#define CHUNK_MAP_KEY ((size_t)0x10U)
#define CHUNK_MAP_DIRTY ((size_t)0x08U)
#define CHUNK_MAP_ZEROED ((size_t)0x04U)
#define CHUNK_MAP_LARGE ((size_t)0x02U)
#define CHUNK_MAP_ALLOCATED ((size_t)0x01U)
};
+
struct ArenaChunkMapLink
{
static RedBlackTreeNode<arena_chunk_map_t>& GetTreeNode(arena_chunk_map_t* aThis)
{
return aThis->link;
}
};
@@ -818,39 +778,39 @@ struct ArenaAvailTreeTrait : public Aren
{
size_t size1 = aNode->bits & ~pagesize_mask;
size_t size2 = aOther->bits & ~pagesize_mask;
int ret = (size1 > size2) - (size1 < size2);
return ret ? ret : CompareAddr((aNode->bits & CHUNK_MAP_KEY) ? nullptr : aNode, aOther);
}
};
-/* Arena chunk header. */
+// Arena chunk header.
struct arena_chunk_t {
- /* Arena that owns the chunk. */
+ // Arena that owns the chunk.
arena_t *arena;
- /* Linkage for the arena's tree of dirty chunks. */
+ // Linkage for the arena's tree of dirty chunks.
RedBlackTreeNode<arena_chunk_t> link_dirty;
#ifdef MALLOC_DOUBLE_PURGE
- /* If we're double-purging, we maintain a linked list of chunks which
- * have pages which have been madvise(MADV_FREE)'d but not explicitly
- * purged.
- *
- * We're currently lazy and don't remove a chunk from this list when
- * all its madvised pages are recommitted. */
+ // If we're double-purging, we maintain a linked list of chunks which
+ // have pages which have been madvise(MADV_FREE)'d but not explicitly
+ // purged.
+ //
+ // We're currently lazy and don't remove a chunk from this list when
+ // all its madvised pages are recommitted.
mozilla::DoublyLinkedListElement<arena_chunk_t> chunks_madvised_elem;
#endif
- /* Number of dirty pages. */
+ // Number of dirty pages.
size_t ndirty;
- /* Map of pages within chunk that keeps track of free/large/small. */
- arena_chunk_map_t map[1]; /* Dynamically sized. */
+ // Map of pages within chunk that keeps track of free/large/small.
+ arena_chunk_map_t map[1]; // Dynamically sized.
};
struct ArenaDirtyChunkTrait
{
static RedBlackTreeNode<arena_chunk_t>& GetTreeNode(arena_chunk_t* aThis)
{
return aThis->link_dirty;
}
@@ -879,146 +839,133 @@ struct GetDoublyLinkedListElement<arena_
#endif
struct arena_run_t {
#if defined(MOZ_DEBUG) || defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED)
uint32_t magic;
# define ARENA_RUN_MAGIC 0x384adf93
#endif
- /* Bin this run is associated with. */
+ // Bin this run is associated with.
arena_bin_t *bin;
- /* Index of first element that might have a free region. */
+ // Index of first element that might have a free region.
unsigned regs_minelm;
- /* Number of free regions in run. */
+ // Number of free regions in run.
unsigned nfree;
- /* Bitmask of in-use regions (0: in use, 1: free). */
- unsigned regs_mask[1]; /* Dynamically sized. */
+ // Bitmask of in-use regions (0: in use, 1: free).
+ unsigned regs_mask[1]; // Dynamically sized.
};
struct arena_bin_t {
- /*
- * Current run being used to service allocations of this bin's size
- * class.
- */
+ // Current run being used to service allocations of this bin's size
+ // class.
arena_run_t *runcur;
- /*
- * Tree of non-full runs. This tree is used when looking for an
- * existing run when runcur is no longer usable. We choose the
- * non-full run that is lowest in memory; this policy tends to keep
- * objects packed well, and it can also help reduce the number of
- * almost-empty chunks.
- */
+ // Tree of non-full runs. This tree is used when looking for an
+ // existing run when runcur is no longer usable. We choose the
+ // non-full run that is lowest in memory; this policy tends to keep
+ // objects packed well, and it can also help reduce the number of
+ // almost-empty chunks.
RedBlackTree<arena_chunk_map_t, ArenaRunTreeTrait> runs;
- /* Size of regions in a run for this bin's size class. */
+ // Size of regions in a run for this bin's size class.
size_t reg_size;
- /* Total size of a run for this bin's size class. */
+ // Total size of a run for this bin's size class.
size_t run_size;
- /* Total number of regions in a run for this bin's size class. */
+ // Total number of regions in a run for this bin's size class.
uint32_t nregs;
- /* Number of elements in a run's regs_mask for this bin's size class. */
+ // Number of elements in a run's regs_mask for this bin's size class.
uint32_t regs_mask_nelms;
- /* Offset of first region in a run for this bin's size class. */
+ // Offset of first region in a run for this bin's size class.
uint32_t reg0_offset;
- /* Bin statistics. */
+ // Bin statistics.
malloc_bin_stats_t stats;
};
struct arena_t {
#if defined(MOZ_DEBUG) || defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED)
uint32_t mMagic;
# define ARENA_MAGIC 0x947d3d24
#endif
arena_id_t mId;
- /* Linkage for the tree of arenas by id. */
+ // Linkage for the tree of arenas by id.
RedBlackTreeNode<arena_t> mLink;
- /* All operations on this arena require that lock be locked. */
+ // All operations on this arena require that lock be locked.
Mutex mLock;
arena_stats_t mStats;
private:
- /* Tree of dirty-page-containing chunks this arena manages. */
+ // Tree of dirty-page-containing chunks this arena manages.
RedBlackTree<arena_chunk_t, ArenaDirtyChunkTrait> mChunksDirty;
#ifdef MALLOC_DOUBLE_PURGE
- /* Head of a linked list of MADV_FREE'd-page-containing chunks this
- * arena manages. */
+ // Head of a linked list of MADV_FREE'd-page-containing chunks this
+ // arena manages.
mozilla::DoublyLinkedList<arena_chunk_t> mChunksMAdvised;
#endif
- /*
- * In order to avoid rapid chunk allocation/deallocation when an arena
- * oscillates right on the cusp of needing a new chunk, cache the most
- * recently freed chunk. The spare is left in the arena's chunk trees
- * until it is deleted.
- *
- * There is one spare chunk per arena, rather than one spare total, in
- * order to avoid interactions between multiple threads that could make
- * a single spare inadequate.
- */
+ // In order to avoid rapid chunk allocation/deallocation when an arena
+ // oscillates right on the cusp of needing a new chunk, cache the most
+ // recently freed chunk. The spare is left in the arena's chunk trees
+ // until it is deleted.
+ //
+ // There is one spare chunk per arena, rather than one spare total, in
+ // order to avoid interactions between multiple threads that could make
+ // a single spare inadequate.
arena_chunk_t* mSpare;
public:
- /*
- * Current count of pages within unused runs that are potentially
- * dirty, and for which madvise(... MADV_FREE) has not been called. By
- * tracking this, we can institute a limit on how much dirty unused
- * memory is mapped for each arena.
- */
+ // Current count of pages within unused runs that are potentially
+ // dirty, and for which madvise(... MADV_FREE) has not been called. By
+ // tracking this, we can institute a limit on how much dirty unused
+ // memory is mapped for each arena.
size_t mNumDirty;
- /*
- * Maximum value allowed for mNumDirty.
- */
+
+ // Maximum value allowed for mNumDirty.
size_t mMaxDirty;
private:
- /*
- * Size/address-ordered tree of this arena's available runs. This tree
- * is used for first-best-fit run allocation.
- */
+ // Size/address-ordered tree of this arena's available runs. This tree
+ // is used for first-best-fit run allocation.
RedBlackTree<arena_chunk_map_t, ArenaAvailTreeTrait> mRunsAvail;
public:
- /*
- * mBins is used to store rings of free regions of the following sizes,
- * assuming a 16-byte quantum, 4kB pagesize, and default MALLOC_OPTIONS.
- *
- * mBins[i] | size |
- * --------+------+
- * 0 | 2 |
- * 1 | 4 |
- * 2 | 8 |
- * --------+------+
- * 3 | 16 |
- * 4 | 32 |
- * 5 | 48 |
- * 6 | 64 |
- * : :
- * : :
- * 33 | 496 |
- * 34 | 512 |
- * --------+------+
- * 35 | 1024 |
- * 36 | 2048 |
- * --------+------+
- */
- arena_bin_t mBins[1]; /* Dynamically sized. */
+ // mBins is used to store rings of free regions of the following sizes,
+ // assuming a 16-byte quantum, 4kB pagesize, and default MALLOC_OPTIONS.
+ //
+ // mBins[i] | size |
+ // --------+------+
+ // 0 | 2 |
+ // 1 | 4 |
+ // 2 | 8 |
+ // --------+------+
+ // 3 | 16 |
+ // 4 | 32 |
+ // 5 | 48 |
+ // 6 | 64 |
+ // : :
+ // : :
+ // 33 | 496 |
+ // 34 | 512 |
+ // --------+------+
+ // 35 | 1024 |
+ // 36 | 2048 |
+ // --------+------+
+ arena_bin_t mBins[1]; // Dynamically sized.
bool Init();
static inline arena_t* GetById(arena_id_t aArenaId);
private:
void InitChunk(arena_chunk_t* aChunk, bool aZeroed);
@@ -1072,113 +1019,98 @@ struct ArenaTreeTrait
static inline int Compare(arena_t* aNode, arena_t* aOther)
{
MOZ_ASSERT(aNode);
MOZ_ASSERT(aOther);
return (aNode->mId > aOther->mId) - (aNode->mId < aOther->mId);
}
};
-/********/
-/*
- * Chunks.
- */
-
+// ******
+// Chunks.
static AddressRadixTree<(SIZEOF_PTR << 3) - CHUNK_2POW_DEFAULT> gChunkRTree;
-/* Protects chunk-related data structures. */
+// Protects chunk-related data structures.
static Mutex chunks_mtx;
-/*
- * Trees of chunks that were previously allocated (trees differ only in node
- * ordering). These are used when allocating chunks, in an attempt to re-use
- * address space. Depending on function, different tree orderings are needed,
- * which is why there are two trees with the same contents.
- */
+// Trees of chunks that were previously allocated (trees differ only in node
+// ordering). These are used when allocating chunks, in an attempt to re-use
+// address space. Depending on function, different tree orderings are needed,
+// which is why there are two trees with the same contents.
static RedBlackTree<extent_node_t, ExtentTreeSzTrait> gChunksBySize;
static RedBlackTree<extent_node_t, ExtentTreeTrait> gChunksByAddress;
-/* Protects huge allocation-related data structures. */
+// Protects huge allocation-related data structures.
static Mutex huge_mtx;
-/* Tree of chunks that are stand-alone huge allocations. */
+// Tree of chunks that are stand-alone huge allocations.
static RedBlackTree<extent_node_t, ExtentTreeTrait> huge;
-/* Huge allocation statistics. */
+// Huge allocation statistics.
static size_t huge_allocated;
static size_t huge_mapped;
-/****************************/
-/*
- * base (internal allocation).
- */
-
-/*
- * Current pages that are being used for internal memory allocations. These
- * pages are carved up in cacheline-size quanta, so that there is no chance of
- * false cache line sharing.
- */
+// **************************
+// base (internal allocation).
+
+// Current pages that are being used for internal memory allocations. These
+// pages are carved up in cacheline-size quanta, so that there is no chance of
+// false cache line sharing.
+
static void *base_pages;
static void *base_next_addr;
static void *base_next_decommitted;
-static void *base_past_addr; /* Addr immediately past base_pages. */
+static void *base_past_addr; // Addr immediately past base_pages.
static extent_node_t *base_nodes;
static Mutex base_mtx;
static size_t base_mapped;
static size_t base_committed;
-/********/
-/*
- * Arenas.
- */
+// ******
+// Arenas.
// A tree of all available arenas, arranged by id.
// TODO: Move into arena_t as a static member when rb_tree doesn't depend on
// the type being defined anymore.
static RedBlackTree<arena_t, ArenaTreeTrait> gArenaTree;
static unsigned narenas;
-static Mutex arenas_lock; /* Protects arenas initialization. */
-
-/*
- * The arena associated with the current thread (per jemalloc_thread_local_arena)
- * On OSX, __thread/thread_local circles back calling malloc to allocate storage
- * on first access on each thread, which leads to an infinite loop, but
- * pthread-based TLS somehow doesn't have this problem.
- */
+static Mutex arenas_lock; // Protects arenas initialization.
+
+// The arena associated with the current thread (per jemalloc_thread_local_arena)
+// On OSX, __thread/thread_local circles back calling malloc to allocate storage
+// on first access on each thread, which leads to an infinite loop, but
+// pthread-based TLS somehow doesn't have this problem.
#if !defined(XP_DARWIN)
static MOZ_THREAD_LOCAL(arena_t*) thread_arena;
#else
static mozilla::detail::ThreadLocal<arena_t*, mozilla::detail::ThreadLocalKeyStorage> thread_arena;
#endif
// The main arena, which all threads default to until jemalloc_thread_local_arena
// is called.
static arena_t *gMainArena;
-/*******************************/
-/*
- * Runtime configuration options.
- */
+// *****************************
+// Runtime configuration options.
+
const uint8_t kAllocJunk = 0xe4;
const uint8_t kAllocPoison = 0xe5;
#ifdef MOZ_DEBUG
static bool opt_junk = true;
static bool opt_zero = false;
#else
static const bool opt_junk = false;
static const bool opt_zero = false;
#endif
static size_t opt_dirty_max = DIRTY_MAX_DEFAULT;
-/******************************************************************************/
-/*
- * Begin forward declarations.
- */
+// ***************************************************************************
+// Begin forward declarations.
static void* chunk_alloc(size_t aSize, size_t aAlignment, bool aBase, bool* aZeroed = nullptr);
static void chunk_dealloc(void* aChunk, size_t aSize, ChunkType aType);
static void chunk_ensure_zero(void* aPtr, size_t aSize, bool aZeroed);
static arena_t *arenas_extend();
static void *huge_malloc(size_t size, bool zero);
static void* huge_palloc(size_t aSize, size_t aAlignment, bool aZero);
static void* huge_ralloc(void* aPtr, size_t aSize, size_t aOldSize);
@@ -1194,20 +1126,18 @@ bool malloc_init_hard(void);
#define FORK_HOOK extern "C"
#else
#define FORK_HOOK static
#endif
FORK_HOOK void _malloc_prefork(void);
FORK_HOOK void _malloc_postfork_parent(void);
FORK_HOOK void _malloc_postfork_child(void);
-/*
- * End forward declarations.
- */
-/******************************************************************************/
+// End forward declarations.
+// ***************************************************************************
static void
_malloc_message(const char *p)
{
#if !defined(XP_WIN)
#define _write write
#endif
// Pretend to check _write() errors to suppress gcc warnings about
@@ -1232,23 +1162,21 @@ static void
// instead of the one defined here; use only MozTagAnonymousMemory().
#ifdef ANDROID
// Android's pthread.h does not declare pthread_atfork() until SDK 21.
extern "C" MOZ_EXPORT
int pthread_atfork(void (*)(void), void (*)(void), void(*)(void));
#endif
-/******************************************************************************/
-/*
- * Begin mutex. We can't use normal pthread mutexes in all places, because
- * they require malloc()ed memory, which causes bootstrapping issues in some
- * cases. We also can't use constructors, because for statics, they would fire
- * after the first use of malloc, resetting the locks.
- */
+// ***************************************************************************
+// Begin mutex. We can't use normal pthread mutexes in all places, because
+// they require malloc()ed memory, which causes bootstrapping issues in some
+// cases. We also can't use constructors, because for statics, they would fire
+// after the first use of malloc, resetting the locks.
// Initializes a mutex. Returns whether initialization succeeded.
bool
Mutex::Init()
{
#if defined(XP_WIN)
if (!InitializeCriticalSectionAndSpinCount(&mMutex, _CRT_SPINCOUNT)) {
return false;
@@ -1293,55 +1221,51 @@ Mutex::Unlock()
LeaveCriticalSection(&mMutex);
#elif defined(XP_DARWIN)
OSSpinLockUnlock(&mMutex);
#else
pthread_mutex_unlock(&mMutex);
#endif
}
-/*
- * End mutex.
- */
-/******************************************************************************/
-/*
- * Begin Utility functions/macros.
- */
-
-/* Return the chunk address for allocation address a. */
+// End mutex.
+// ***************************************************************************
+// Begin Utility functions/macros.
+
+// Return the chunk address for allocation address a.
static inline arena_chunk_t*
GetChunkForPtr(const void* aPtr)
{
return (arena_chunk_t*)(uintptr_t(aPtr) & ~chunksize_mask);
}
-/* Return the chunk offset of address a. */
+// Return the chunk offset of address a.
static inline size_t
GetChunkOffsetForPtr(const void* aPtr)
{
return (size_t)(uintptr_t(aPtr) & chunksize_mask);
}
-/* Return the smallest chunk multiple that is >= s. */
+// Return the smallest chunk multiple that is >= s.
#define CHUNK_CEILING(s) \
(((s) + chunksize_mask) & ~chunksize_mask)
-/* Return the smallest cacheline multiple that is >= s. */
+// Return the smallest cacheline multiple that is >= s.
#define CACHELINE_CEILING(s) \
(((s) + (CACHELINE - 1)) & ~(CACHELINE - 1))
-/* Return the smallest quantum multiple that is >= a. */
+// Return the smallest quantum multiple that is >= a.
#define QUANTUM_CEILING(a) \
(((a) + quantum_mask) & ~quantum_mask)
-/* Return the smallest pagesize multiple that is >= s. */
+// Return the smallest pagesize multiple that is >= s.
#define PAGE_CEILING(s) \
(((s) + pagesize_mask) & ~pagesize_mask)
-/* Compute the smallest power of 2 that is >= x. */
+// Compute the smallest power of 2 that is >= x.
static inline size_t
pow2_ceil(size_t x)
{
x--;
x |= x >> 1;
x |= x >> 2;
x |= x >> 4;
@@ -1356,28 +1280,26 @@ pow2_ceil(size_t x)
static inline const char *
_getprogname(void)
{
return "<jemalloc>";
}
-/******************************************************************************/
+// ***************************************************************************
static inline void
pages_decommit(void* aAddr, size_t aSize)
{
#ifdef XP_WIN
- /*
- * The region starting at addr may have been allocated in multiple calls
- * to VirtualAlloc and recycled, so decommitting the entire region in one
- * go may not be valid. However, since we allocate at least a chunk at a
- * time, we may touch any region in chunksized increments.
- */
+ // The region starting at addr may have been allocated in multiple calls
+ // to VirtualAlloc and recycled, so decommitting the entire region in one
+ // go may not be valid. However, since we allocate at least a chunk at a
+ // time, we may touch any region in chunksized increments.
size_t pages_size = std::min(aSize, chunksize - GetChunkOffsetForPtr(aAddr));
while (aSize > 0) {
if (!VirtualFree(aAddr, pages_size, MEM_DECOMMIT)) {
MOZ_CRASH();
}
aAddr = (void*)((uintptr_t)aAddr + pages_size);
aSize -= pages_size;
pages_size = std::min(aSize, chunksize);
@@ -1386,27 +1308,25 @@ pages_decommit(void* aAddr, size_t aSize
if (mmap(aAddr, aSize, PROT_NONE, MAP_FIXED | MAP_PRIVATE | MAP_ANON, -1, 0) ==
MAP_FAILED) {
MOZ_CRASH();
}
MozTagAnonymousMemory(aAddr, aSize, "jemalloc-decommitted");
#endif
}
-/* Commit pages. Returns whether pages were committed. */
+// Commit pages. Returns whether pages were committed.
MOZ_MUST_USE static inline bool
pages_commit(void* aAddr, size_t aSize)
{
#ifdef XP_WIN
- /*
- * The region starting at addr may have been allocated in multiple calls
- * to VirtualAlloc and recycled, so committing the entire region in one
- * go may not be valid. However, since we allocate at least a chunk at a
- * time, we may touch any region in chunksized increments.
- */
+ // The region starting at addr may have been allocated in multiple calls
+ // to VirtualAlloc and recycled, so committing the entire region in one
+ // go may not be valid. However, since we allocate at least a chunk at a
+ // time, we may touch any region in chunksized increments.
size_t pages_size = std::min(aSize, chunksize - GetChunkOffsetForPtr(aAddr));
while (aSize > 0) {
if (!VirtualAlloc(aAddr, pages_size, MEM_COMMIT, PAGE_READWRITE)) {
return false;
}
aAddr = (void*)((uintptr_t)aAddr + pages_size);
aSize -= pages_size;
pages_size = std::min(aSize, chunksize);
@@ -1434,20 +1354,18 @@ base_pages_alloc(size_t minsize)
MOZ_ASSERT(minsize != 0);
csize = CHUNK_CEILING(minsize);
base_pages = chunk_alloc(csize, chunksize, true);
if (!base_pages) {
return true;
}
base_next_addr = base_pages;
base_past_addr = (void *)((uintptr_t)base_pages + csize);
- /*
- * Leave enough pages for minsize committed, since otherwise they would
- * have to be immediately recommitted.
- */
+ // Leave enough pages for minsize committed, since otherwise they would
+ // have to be immediately recommitted.
pminsize = PAGE_CEILING(minsize);
base_next_decommitted = (void *)((uintptr_t)base_pages + pminsize);
# if defined(MALLOC_DECOMMIT)
if (pminsize < csize) {
pages_decommit(base_next_decommitted, csize - pminsize);
}
# endif
base_mapped += csize;
@@ -1457,30 +1375,30 @@ base_pages_alloc(size_t minsize)
}
static void*
base_alloc(size_t aSize)
{
void* ret;
size_t csize;
- /* Round size up to nearest multiple of the cacheline size. */
+ // Round size up to nearest multiple of the cacheline size.
csize = CACHELINE_CEILING(aSize);
MutexAutoLock lock(base_mtx);
- /* Make sure there's enough space for the allocation. */
+ // Make sure there's enough space for the allocation.
if ((uintptr_t)base_next_addr + csize > (uintptr_t)base_past_addr) {
if (base_pages_alloc(csize)) {
return nullptr;
}
}
- /* Allocate. */
+ // Allocate.
ret = base_next_addr;
base_next_addr = (void*)((uintptr_t)base_next_addr + csize);
- /* Make sure enough pages are committed for the new allocation. */
+ // Make sure enough pages are committed for the new allocation.
if ((uintptr_t)base_next_addr > (uintptr_t)base_next_decommitted) {
void* pbase_next_addr = (void*)(PAGE_CEILING((uintptr_t)base_next_addr));
# ifdef MALLOC_DECOMMIT
if (!pages_commit(base_next_decommitted,
(uintptr_t)pbase_next_addr -
(uintptr_t)base_next_decommitted)) {
return nullptr;
@@ -1532,23 +1450,19 @@ base_node_dealloc(extent_node_t* aNode)
struct BaseNodeFreePolicy
{
void operator()(extent_node_t* aPtr) { base_node_dealloc(aPtr); }
};
using UniqueBaseNode = mozilla::UniquePtr<extent_node_t, BaseNodeFreePolicy>;
-/*
- * End Utility functions/macros.
- */
-/******************************************************************************/
-/*
- * Begin chunk management functions.
- */
+// End Utility functions/macros.
+// ***************************************************************************
+// Begin chunk management functions.
#ifdef XP_WIN
static void *
pages_map(void *aAddr, size_t aSize)
{
void *ret = nullptr;
ret = VirtualAlloc(aAddr, aSize, MEM_COMMIT | MEM_RESERVE,
@@ -1579,86 +1493,76 @@ pages_unmap(void *aAddr, size_t aSize)
}
}
static void *
pages_map(void *aAddr, size_t aSize)
{
void *ret;
#if defined(__ia64__) || (defined(__sparc__) && defined(__arch64__) && defined(__linux__))
- /*
- * The JS engine assumes that all allocated pointers have their high 17 bits clear,
- * which ia64's mmap doesn't support directly. However, we can emulate it by passing
- * mmap an "addr" parameter with those bits clear. The mmap will return that address,
- * or the nearest available memory above that address, providing a near-guarantee
- * that those bits are clear. If they are not, we return nullptr below to indicate
- * out-of-memory.
- *
- * The addr is chosen as 0x0000070000000000, which still allows about 120TB of virtual
- * address space.
- *
- * See Bug 589735 for more information.
- */
+ // The JS engine assumes that all allocated pointers have their high 17 bits clear,
+ // which ia64's mmap doesn't support directly. However, we can emulate it by passing
+ // mmap an "addr" parameter with those bits clear. The mmap will return that address,
+ // or the nearest available memory above that address, providing a near-guarantee
+ // that those bits are clear. If they are not, we return nullptr below to indicate
+ // out-of-memory.
+ //
+ // The addr is chosen as 0x0000070000000000, which still allows about 120TB of virtual
+ // address space.
+ //
+ // See Bug 589735 for more information.
bool check_placement = true;
if (!aAddr) {
aAddr = (void*)0x0000070000000000;
check_placement = false;
}
#endif
#if defined(__sparc__) && defined(__arch64__) && defined(__linux__)
const uintptr_t start = 0x0000070000000000ULL;
const uintptr_t end = 0x0000800000000000ULL;
- /* Copied from js/src/gc/Memory.cpp and adapted for this source */
-
+ // Copied from js/src/gc/Memory.cpp and adapted for this source
uintptr_t hint;
void* region = MAP_FAILED;
for (hint = start; region == MAP_FAILED && hint + aSize <= end; hint += chunksize) {
region = mmap((void*)hint, aSize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
if (region != MAP_FAILED) {
if (((size_t) region + (aSize - 1)) & 0xffff800000000000) {
if (munmap(region, aSize)) {
MOZ_ASSERT(errno == ENOMEM);
}
region = MAP_FAILED;
}
}
}
ret = region;
#else
-
- /*
- * We don't use MAP_FIXED here, because it can cause the *replacement*
- * of existing mappings, and we only want to create new mappings.
- */
+ // We don't use MAP_FIXED here, because it can cause the *replacement*
+ // of existing mappings, and we only want to create new mappings.
ret = mmap(aAddr, aSize, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
MOZ_ASSERT(ret);
#endif
if (ret == MAP_FAILED) {
ret = nullptr;
}
#if defined(__ia64__) || (defined(__sparc__) && defined(__arch64__) && defined(__linux__))
- /*
- * If the allocated memory doesn't have its upper 17 bits clear, consider it
- * as out of memory.
- */
+ // If the allocated memory doesn't have its upper 17 bits clear, consider it
+ // as out of memory.
else if ((long long)ret & 0xffff800000000000) {
munmap(ret, aSize);
ret = nullptr;
}
- /* If the caller requested a specific memory location, verify that's what mmap returned. */
+ // If the caller requested a specific memory location, verify that's what mmap returned.
else if (check_placement && ret != aAddr) {
#else
else if (aAddr && ret != aAddr) {
#endif
- /*
- * We succeeded in mapping memory, but not in the right place.
- */
+ // We succeeded in mapping memory, but not in the right place.
pages_unmap(ret, aSize);
ret = nullptr;
}
if (ret) {
MozTagAnonymousMemory(ret, aSize, "jemalloc");
}
#if defined(__ia64__) || (defined(__sparc__) && defined(__arch64__) && defined(__linux__))
@@ -1718,20 +1622,18 @@ AddressRadixTree<Bits>::GetSlot(void* aK
node[subkey] = child;
}
}
if (!child) {
return nullptr;
}
}
- /*
- * node is a leaf, so it contains values rather than node
- * pointers.
- */
+ // node is a leaf, so it contains values rather than node
+ // pointers.
bits = i ? kBitsPerLevel : kBitsAtLevel1;
subkey = (key << lshift) >> ((SIZEOF_PTR << 3) - bits);
return &node[subkey];
}
template <size_t Bits>
void*
AddressRadixTree<Bits>::Get(void* aKey)
@@ -1740,25 +1642,24 @@ AddressRadixTree<Bits>::Get(void* aKey)
void** slot = GetSlot(aKey);
if (slot) {
ret = *slot;
}
#ifdef MOZ_DEBUG
MutexAutoLock lock(mLock);
- /*
- * Suppose that it were possible for a jemalloc-allocated chunk to be
- * munmap()ped, followed by a different allocator in another thread re-using
- * overlapping virtual memory, all without invalidating the cached rtree
- * value. The result would be a false positive (the rtree would claim that
- * jemalloc owns memory that it had actually discarded). I don't think this
- * scenario is possible, but the following assertion is a prudent sanity
- * check.
- */
+
+ // Suppose that it were possible for a jemalloc-allocated chunk to be
+ // munmap()ped, followed by a different allocator in another thread re-using
+ // overlapping virtual memory, all without invalidating the cached rtree
+ // value. The result would be a false positive (the rtree would claim that
+ // jemalloc owns memory that it had actually discarded). I don't think this
+ // scenario is possible, but the following assertion is a prudent sanity
+ // check.
if (!slot) {
// In case a slot has been created in the meantime.
slot = GetSlot(aKey);
}
if (slot) {
// The MutexAutoLock above should act as a memory barrier, forcing
// the compiler to emit a new read instruction for *slot.
MOZ_ASSERT(ret == *slot);
@@ -1769,31 +1670,31 @@ AddressRadixTree<Bits>::Get(void* aKey)
return ret;
}
template <size_t Bits>
bool
AddressRadixTree<Bits>::Set(void* aKey, void* aValue)
{
MutexAutoLock lock(mLock);
- void** slot = GetSlot(aKey, /* create */ true);
+ void** slot = GetSlot(aKey, /* create = */ true);
if (slot) {
*slot = aValue;
}
return slot;
}
-/* pages_trim, chunk_alloc_mmap_slow and chunk_alloc_mmap were cherry-picked
- * from upstream jemalloc 3.4.1 to fix Mozilla bug 956501. */
-
-/* Return the offset between a and the nearest aligned address at or below a. */
+// pages_trim, chunk_alloc_mmap_slow and chunk_alloc_mmap were cherry-picked
+// from upstream jemalloc 3.4.1 to fix Mozilla bug 956501.
+
+// Return the offset between a and the nearest aligned address at or below a.
#define ALIGNMENT_ADDR2OFFSET(a, alignment) \
((size_t)((uintptr_t)(a) & (alignment - 1)))
-/* Return the smallest alignment multiple that is >= s. */
+// Return the smallest alignment multiple that is >= s.
#define ALIGNMENT_CEILING(s, alignment) \
(((s) + (alignment - 1)) & (~(alignment - 1)))
static void *
pages_trim(void *addr, size_t alloc_size, size_t leadsize, size_t size)
{
void *ret = (void *)((uintptr_t)addr + leadsize);
@@ -1829,17 +1730,17 @@ pages_trim(void *addr, size_t alloc_size
static void *
chunk_alloc_mmap_slow(size_t size, size_t alignment)
{
void *ret, *pages;
size_t alloc_size, leadsize;
alloc_size = size + alignment - pagesize;
- /* Beware size_t wrap-around. */
+ // Beware size_t wrap-around.
if (alloc_size < size) {
return nullptr;
}
do {
pages = pages_map(nullptr, alloc_size);
if (!pages) {
return nullptr;
}
@@ -1853,83 +1754,77 @@ chunk_alloc_mmap_slow(size_t size, size_
}
static void *
chunk_alloc_mmap(size_t size, size_t alignment)
{
void *ret;
size_t offset;
- /*
- * Ideally, there would be a way to specify alignment to mmap() (like
- * NetBSD has), but in the absence of such a feature, we have to work
- * hard to efficiently create aligned mappings. The reliable, but
- * slow method is to create a mapping that is over-sized, then trim the
- * excess. However, that always results in one or two calls to
- * pages_unmap().
- *
- * Optimistically try mapping precisely the right amount before falling
- * back to the slow method, with the expectation that the optimistic
- * approach works most of the time.
- */
-
+ // Ideally, there would be a way to specify alignment to mmap() (like
+ // NetBSD has), but in the absence of such a feature, we have to work
+ // hard to efficiently create aligned mappings. The reliable, but
+ // slow method is to create a mapping that is over-sized, then trim the
+ // excess. However, that always results in one or two calls to
+ // pages_unmap().
+ //
+ // Optimistically try mapping precisely the right amount before falling
+ // back to the slow method, with the expectation that the optimistic
+ // approach works most of the time.
ret = pages_map(nullptr, size);
if (!ret) {
return nullptr;
}
offset = ALIGNMENT_ADDR2OFFSET(ret, alignment);
if (offset != 0) {
pages_unmap(ret, size);
return chunk_alloc_mmap_slow(size, alignment);
}
MOZ_ASSERT(ret);
return ret;
}
-/* Purge and release the pages in the chunk of length `length` at `addr` to
- * the OS.
- * Returns whether the pages are guaranteed to be full of zeroes when the
- * function returns.
- * The force_zero argument explicitly requests that the memory is guaranteed
- * to be full of zeroes when the function returns.
- */
+// Purge and release the pages in the chunk of length `length` at `addr` to
+// the OS.
+// Returns whether the pages are guaranteed to be full of zeroes when the
+// function returns.
+// The force_zero argument explicitly requests that the memory is guaranteed
+// to be full of zeroes when the function returns.
static bool
pages_purge(void *addr, size_t length, bool force_zero)
{
#ifdef MALLOC_DECOMMIT
pages_decommit(addr, length);
return true;
#else
# ifndef XP_LINUX
if (force_zero) {
memset(addr, 0, length);
}
# endif
# ifdef XP_WIN
- /*
- * The region starting at addr may have been allocated in multiple calls
- * to VirtualAlloc and recycled, so resetting the entire region in one
- * go may not be valid. However, since we allocate at least a chunk at a
- * time, we may touch any region in chunksized increments.
- */
+ // The region starting at addr may have been allocated in multiple calls
+ // to VirtualAlloc and recycled, so resetting the entire region in one
+ // go may not be valid. However, since we allocate at least a chunk at a
+ // time, we may touch any region in chunksized increments.
size_t pages_size = std::min(length, chunksize -
GetChunkOffsetForPtr(addr));
while (length > 0) {
VirtualAlloc(addr, pages_size, MEM_RESET, PAGE_READWRITE);
addr = (void *)((uintptr_t)addr + pages_size);
length -= pages_size;
pages_size = std::min(length, chunksize);
}
return force_zero;
# else
# ifdef XP_LINUX
# define JEMALLOC_MADV_PURGE MADV_DONTNEED
# define JEMALLOC_MADV_ZEROS true
-# else /* FreeBSD and Darwin. */
+# else // FreeBSD and Darwin.
# define JEMALLOC_MADV_PURGE MADV_FREE
# define JEMALLOC_MADV_ZEROS force_zero
# endif
int err = madvise(addr, length, JEMALLOC_MADV_PURGE);
return JEMALLOC_MADV_ZEROS && err == 0;
# undef JEMALLOC_MADV_PURGE
# undef JEMALLOC_MADV_ZEROS
# endif
@@ -1937,17 +1832,17 @@ pages_purge(void *addr, size_t length, b
}
static void*
chunk_recycle(size_t aSize, size_t aAlignment, bool* aZeroed)
{
extent_node_t key;
size_t alloc_size = aSize + aAlignment - chunksize;
- /* Beware size_t wrap-around. */
+ // Beware size_t wrap-around.
if (alloc_size < aSize) {
return nullptr;
}
key.addr = nullptr;
key.size = alloc_size;
chunks_mtx.Lock();
extent_node_t* node = gChunksBySize.SearchOrNext(&key);
if (!node) {
@@ -1958,36 +1853,34 @@ chunk_recycle(size_t aSize, size_t aAlig
ALIGNMENT_CEILING((uintptr_t)node->addr, aAlignment) - (uintptr_t)node->addr;
MOZ_ASSERT(node->size >= leadsize + aSize);
size_t trailsize = node->size - leadsize - aSize;
void* ret = (void*)((uintptr_t)node->addr + leadsize);
ChunkType chunk_type = node->chunk_type;
if (aZeroed) {
*aZeroed = (chunk_type == ZEROED_CHUNK);
}
- /* Remove node from the tree. */
+ // Remove node from the tree.
gChunksBySize.Remove(node);
gChunksByAddress.Remove(node);
if (leadsize != 0) {
- /* Insert the leading space as a smaller chunk. */
+ // Insert the leading space as a smaller chunk.
node->size = leadsize;
gChunksBySize.Insert(node);
gChunksByAddress.Insert(node);
node = nullptr;
}
if (trailsize != 0) {
- /* Insert the trailing space as a smaller chunk. */
+ // Insert the trailing space as a smaller chunk.
if (!node) {
- /*
- * An additional node is required, but
- * base_node_alloc() can cause a new base chunk to be
- * allocated. Drop chunks_mtx in order to avoid
- * deadlock, and if node allocation fails, deallocate
- * the result before returning an error.
- */
+ // An additional node is required, but
+ // base_node_alloc() can cause a new base chunk to be
+ // allocated. Drop chunks_mtx in order to avoid
+ // deadlock, and if node allocation fails, deallocate
+ // the result before returning an error.
chunks_mtx.Unlock();
node = base_node_alloc();
if (!node) {
chunk_dealloc(ret, aSize, chunk_type);
return nullptr;
}
chunks_mtx.Lock();
}
@@ -2014,34 +1907,31 @@ chunk_recycle(size_t aSize, size_t aAlig
if (aZeroed) {
*aZeroed = true;
}
#endif
return ret;
}
#ifdef XP_WIN
-/*
- * On Windows, calls to VirtualAlloc and VirtualFree must be matched, making it
- * awkward to recycle allocations of varying sizes. Therefore we only allow
- * recycling when the size equals the chunksize, unless deallocation is entirely
- * disabled.
- */
+// On Windows, calls to VirtualAlloc and VirtualFree must be matched, making it
+// awkward to recycle allocations of varying sizes. Therefore we only allow
+// recycling when the size equals the chunksize, unless deallocation is entirely
+// disabled.
#define CAN_RECYCLE(size) (size == chunksize)
#else
#define CAN_RECYCLE(size) true
#endif
-/* Allocates `size` bytes of system memory aligned for `alignment`.
- * `base` indicates whether the memory will be used for the base allocator
- * (e.g. base_alloc).
- * `zeroed` is an outvalue that returns whether the allocated memory is
- * guaranteed to be full of zeroes. It can be omitted when the caller doesn't
- * care about the result.
- */
+// Allocates `size` bytes of system memory aligned for `alignment`.
+// `base` indicates whether the memory will be used for the base allocator
+// (e.g. base_alloc).
+// `zeroed` is an outvalue that returns whether the allocated memory is
+// guaranteed to be full of zeroes. It can be omitted when the caller doesn't
+// care about the result.
static void*
chunk_alloc(size_t aSize, size_t aAlignment, bool aBase, bool* aZeroed)
{
void* ret = nullptr;
MOZ_ASSERT(aSize != 0);
MOZ_ASSERT((aSize & chunksize_mask) == 0);
MOZ_ASSERT(aAlignment != 0);
@@ -2093,72 +1983,64 @@ chunk_record(void* aChunk, size_t aSize,
extent_node_t key;
if (aType != ZEROED_CHUNK) {
if (pages_purge(aChunk, aSize, aType == HUGE_CHUNK)) {
aType = ZEROED_CHUNK;
}
}
- /*
- * Allocate a node before acquiring chunks_mtx even though it might not
- * be needed, because base_node_alloc() may cause a new base chunk to
- * be allocated, which could cause deadlock if chunks_mtx were already
- * held.
- */
+ // Allocate a node before acquiring chunks_mtx even though it might not
+ // be needed, because base_node_alloc() may cause a new base chunk to
+ // be allocated, which could cause deadlock if chunks_mtx were already
+ // held.
UniqueBaseNode xnode(base_node_alloc());
- /* Use xprev to implement conditional deferred deallocation of prev. */
+ // Use xprev to implement conditional deferred deallocation of prev.
UniqueBaseNode xprev;
- /* RAII deallocates xnode and xprev defined above after unlocking
- * in order to avoid potential dead-locks */
+ // RAII deallocates xnode and xprev defined above after unlocking
+ // in order to avoid potential dead-locks
MutexAutoLock lock(chunks_mtx);
key.addr = (void*)((uintptr_t)aChunk + aSize);
extent_node_t* node = gChunksByAddress.SearchOrNext(&key);
- /* Try to coalesce forward. */
+ // Try to coalesce forward.
if (node && node->addr == key.addr) {
- /*
- * Coalesce chunk with the following address range. This does
- * not change the position within gChunksByAddress, so only
- * remove/insert from/into gChunksBySize.
- */
+ // Coalesce chunk with the following address range. This does
+ // not change the position within gChunksByAddress, so only
+ // remove/insert from/into gChunksBySize.
gChunksBySize.Remove(node);
node->addr = aChunk;
node->size += aSize;
if (node->chunk_type != aType) {
node->chunk_type = RECYCLED_CHUNK;
}
gChunksBySize.Insert(node);
} else {
- /* Coalescing forward failed, so insert a new node. */
+ // Coalescing forward failed, so insert a new node.
if (!xnode) {
- /*
- * base_node_alloc() failed, which is an exceedingly
- * unlikely failure. Leak chunk; its pages have
- * already been purged, so this is only a virtual
- * memory leak.
- */
+ // base_node_alloc() failed, which is an exceedingly
+ // unlikely failure. Leak chunk; its pages have
+ // already been purged, so this is only a virtual
+ // memory leak.
return;
}
node = xnode.release();
node->addr = aChunk;
node->size = aSize;
node->chunk_type = aType;
gChunksByAddress.Insert(node);
gChunksBySize.Insert(node);
}
- /* Try to coalesce backward. */
+ // Try to coalesce backward.
extent_node_t* prev = gChunksByAddress.Prev(node);
if (prev && (void*)((uintptr_t)prev->addr + prev->size) == aChunk) {
- /*
- * Coalesce chunk with the previous address range. This does
- * not change the position within gChunksByAddress, so only
- * remove/insert node from/into gChunksBySize.
- */
+ // Coalesce chunk with the previous address range. This does
+ // not change the position within gChunksByAddress, so only
+ // remove/insert node from/into gChunksBySize.
gChunksBySize.Remove(prev);
gChunksByAddress.Remove(prev);
gChunksBySize.Remove(node);
node->addr = prev->addr;
node->size += prev->size;
if (node->chunk_type != prev->chunk_type) {
node->chunk_type = RECYCLED_CHUNK;
@@ -2199,61 +2081,54 @@ chunk_dealloc(void* aChunk, size_t aSize
}
}
pages_unmap(aChunk, aSize);
}
#undef CAN_RECYCLE
-/*
- * End chunk management functions.
- */
-/******************************************************************************/
-/*
- * Begin arena.
- */
+// End chunk management functions.
+// ***************************************************************************
+// Begin arena.
static inline arena_t *
thread_local_arena(bool enabled)
{
arena_t *arena;
if (enabled) {
- /* The arena will essentially be leaked if this function is
- * called with `false`, but it doesn't matter at the moment.
- * because in practice nothing actually calls this function
- * with `false`, except maybe at shutdown. */
+ // The arena will essentially be leaked if this function is
+ // called with `false`, but it doesn't matter at the moment.
+ // because in practice nothing actually calls this function
+ // with `false`, except maybe at shutdown.
arena = arenas_extend();
} else {
arena = gMainArena;
}
thread_arena.set(arena);
return arena;
}
template<> inline void
MozJemalloc::jemalloc_thread_local_arena(bool aEnabled)
{
thread_local_arena(aEnabled);
}
-/*
- * Choose an arena based on a per-thread value.
- */
+// Choose an arena based on a per-thread value.
static inline arena_t *
choose_arena(size_t size)
{
arena_t *ret = nullptr;
- /*
- * We can only use TLS if this is a PIC library, since for the static
- * library version, libc's malloc is used by TLS allocation, which
- * introduces a bootstrapping issue.
- */
+ // We can only use TLS if this is a PIC library, since for the static
+ // library version, libc's malloc is used by TLS allocation, which
+ // introduces a bootstrapping issue.
+
// Only use a thread local arena for small sizes.
if (size <= small_max) {
ret = thread_arena.get();
}
if (!ret) {
ret = thread_local_arena(false);
}
@@ -2265,81 +2140,76 @@ static inline void *
arena_run_reg_alloc(arena_run_t *run, arena_bin_t *bin)
{
void *ret;
unsigned i, mask, bit, regind;
MOZ_ASSERT(run->magic == ARENA_RUN_MAGIC);
MOZ_ASSERT(run->regs_minelm < bin->regs_mask_nelms);
- /*
- * Move the first check outside the loop, so that run->regs_minelm can
- * be updated unconditionally, without the possibility of updating it
- * multiple times.
- */
+ // Move the first check outside the loop, so that run->regs_minelm can
+ // be updated unconditionally, without the possibility of updating it
+ // multiple times.
i = run->regs_minelm;
mask = run->regs_mask[i];
if (mask != 0) {
- /* Usable allocation found. */
+ // Usable allocation found.
bit = ffs((int)mask) - 1;
regind = ((i << (SIZEOF_INT_2POW + 3)) + bit);
MOZ_ASSERT(regind < bin->nregs);
ret = (void *)(((uintptr_t)run) + bin->reg0_offset
+ (bin->reg_size * regind));
- /* Clear bit. */
+ // Clear bit.
mask ^= (1U << bit);
run->regs_mask[i] = mask;
return ret;
}
for (i++; i < bin->regs_mask_nelms; i++) {
mask = run->regs_mask[i];
if (mask != 0) {
- /* Usable allocation found. */
+ // Usable allocation found.
bit = ffs((int)mask) - 1;
regind = ((i << (SIZEOF_INT_2POW + 3)) + bit);
MOZ_ASSERT(regind < bin->nregs);
ret = (void *)(((uintptr_t)run) + bin->reg0_offset
+ (bin->reg_size * regind));
- /* Clear bit. */
+ // Clear bit.
mask ^= (1U << bit);
run->regs_mask[i] = mask;
- /*
- * Make a note that nothing before this element
- * contains a free region.
- */
- run->regs_minelm = i; /* Low payoff: + (mask == 0); */
+ // Make a note that nothing before this element
+ // contains a free region.
+ run->regs_minelm = i; // Low payoff: + (mask == 0);
return ret;
}
}
- /* Not reached. */
+ // Not reached.
MOZ_DIAGNOSTIC_ASSERT(0);
return nullptr;
}
static inline void
arena_run_reg_dalloc(arena_run_t *run, arena_bin_t *bin, void *ptr, size_t size)
{
- /*
- * To divide by a number D that is not a power of two we multiply
- * by (2^21 / D) and then right shift by 21 positions.
- *
- * X / D
- *
- * becomes
- *
- * (X * size_invs[(D >> QUANTUM_2POW_MIN) - 3]) >> SIZE_INV_SHIFT
- */
+ // To divide by a number D that is not a power of two we multiply
+ // by (2^21 / D) and then right shift by 21 positions.
+ //
+ // X / D
+ //
+ // becomes
+ //
+ // (X * size_invs[(D >> QUANTUM_2POW_MIN) - 3]) >> SIZE_INV_SHIFT
+
#define SIZE_INV_SHIFT 21
#define SIZE_INV(s) (((1U << SIZE_INV_SHIFT) / (s << QUANTUM_2POW_MIN)) + 1)
static const unsigned size_invs[] = {
SIZE_INV(3),
SIZE_INV(4), SIZE_INV(5), SIZE_INV(6), SIZE_INV(7),
SIZE_INV(8), SIZE_INV(9), SIZE_INV(10), SIZE_INV(11),
SIZE_INV(12),SIZE_INV(13), SIZE_INV(14), SIZE_INV(15),
SIZE_INV(16),SIZE_INV(17), SIZE_INV(18), SIZE_INV(19),
@@ -2359,61 +2229,53 @@ arena_run_reg_dalloc(arena_run_t *run, a
#endif
};
unsigned diff, regind, elm, bit;
MOZ_ASSERT(run->magic == ARENA_RUN_MAGIC);
MOZ_ASSERT(((sizeof(size_invs)) / sizeof(unsigned)) + 3
>= (SMALL_MAX_DEFAULT >> QUANTUM_2POW_MIN));
- /*
- * Avoid doing division with a variable divisor if possible. Using
- * actual division here can reduce allocator throughput by over 20%!
- */
+ // Avoid doing division with a variable divisor if possible. Using
+ // actual division here can reduce allocator throughput by over 20%!
diff = (unsigned)((uintptr_t)ptr - (uintptr_t)run - bin->reg0_offset);
if ((size & (size - 1)) == 0) {
- /*
- * log2_table allows fast division of a power of two in the
- * [1..128] range.
- *
- * (x / divisor) becomes (x >> log2_table[divisor - 1]).
- */
+ // log2_table allows fast division of a power of two in the
+ // [1..128] range.
+ //
+ // (x / divisor) becomes (x >> log2_table[divisor - 1]).
static const unsigned char log2_table[] = {
0, 1, 0, 2, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 4,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7
};
if (size <= 128) {
regind = (diff >> log2_table[size - 1]);
} else if (size <= 32768) {
regind = diff >> (8 + log2_table[(size >> 8) - 1]);
} else {
- /*
- * The run size is too large for us to use the lookup
- * table. Use real division.
- */
+ // The run size is too large for us to use the lookup
+ // table. Use real division.
regind = diff / size;
}
} else if (size <= ((sizeof(size_invs) / sizeof(unsigned))
<< QUANTUM_2POW_MIN) + 2) {
regind = size_invs[(size >> QUANTUM_2POW_MIN) - 3] * diff;
regind >>= SIZE_INV_SHIFT;
} else {
- /*
- * size_invs isn't large enough to handle this size class, so
- * calculate regind using actual division. This only happens
- * if the user increases small_max via the 'S' runtime
- * configuration option.
- */
+ // size_invs isn't large enough to handle this size class, so
+ // calculate regind using actual division. This only happens
+ // if the user increases small_max via the 'S' runtime
+ // configuration option.
regind = diff / size;
};
MOZ_DIAGNOSTIC_ASSERT(diff == regind * size);
MOZ_DIAGNOSTIC_ASSERT(regind < bin->nregs);
elm = regind >> (SIZEOF_INT_2POW + 3);
if (elm < run->regs_minelm) {
run->regs_minelm = elm;
@@ -2436,33 +2298,29 @@ arena_t::SplitRun(arena_run_t* aRun, siz
run_ind = (unsigned)((uintptr_t(aRun) - uintptr_t(chunk)) >> pagesize_2pow);
total_pages = (chunk->map[run_ind].bits & ~pagesize_mask) >> pagesize_2pow;
need_pages = (aSize >> pagesize_2pow);
MOZ_ASSERT(need_pages > 0);
MOZ_ASSERT(need_pages <= total_pages);
rem_pages = total_pages - need_pages;
for (i = 0; i < need_pages; i++) {
- /*
- * Commit decommitted pages if necessary. If a decommitted
- * page is encountered, commit all needed adjacent decommitted
- * pages in one operation, in order to reduce system call
- * overhead.
- */
+ // Commit decommitted pages if necessary. If a decommitted
+ // page is encountered, commit all needed adjacent decommitted
+ // pages in one operation, in order to reduce system call
+ // overhead.
if (chunk->map[run_ind + i].bits & CHUNK_MAP_MADVISED_OR_DECOMMITTED) {
size_t j;
- /*
- * Advance i+j to just past the index of the last page
- * to commit. Clear CHUNK_MAP_DECOMMITTED and
- * CHUNK_MAP_MADVISED along the way.
- */
+ // Advance i+j to just past the index of the last page
+ // to commit. Clear CHUNK_MAP_DECOMMITTED and
+ // CHUNK_MAP_MADVISED along the way.
for (j = 0; i + j < need_pages && (chunk->map[run_ind +
i + j].bits & CHUNK_MAP_MADVISED_OR_DECOMMITTED); j++) {
- /* DECOMMITTED and MADVISED are mutually exclusive. */
+ // DECOMMITTED and MADVISED are mutually exclusive.
MOZ_ASSERT(!(chunk->map[run_ind + i + j].bits & CHUNK_MAP_DECOMMITTED &&
chunk->map[run_ind + i + j].bits & CHUNK_MAP_MADVISED));
chunk->map[run_ind + i + j].bits &=
~CHUNK_MAP_MADVISED_OR_DECOMMITTED;
}
# ifdef MALLOC_DECOMMIT
@@ -2481,119 +2339,113 @@ arena_t::SplitRun(arena_run_t* aRun, siz
# endif
mStats.committed += j;
}
}
mRunsAvail.Remove(&chunk->map[run_ind]);
- /* Keep track of trailing unused pages for later use. */
+ // Keep track of trailing unused pages for later use.
if (rem_pages > 0) {
chunk->map[run_ind+need_pages].bits = (rem_pages <<
pagesize_2pow) | (chunk->map[run_ind+need_pages].bits &
pagesize_mask);
chunk->map[run_ind+total_pages-1].bits = (rem_pages <<
pagesize_2pow) | (chunk->map[run_ind+total_pages-1].bits &
pagesize_mask);
mRunsAvail.Insert(&chunk->map[run_ind+need_pages]);
}
for (i = 0; i < need_pages; i++) {
- /* Zero if necessary. */
+ // Zero if necessary.
if (aZero) {
if ((chunk->map[run_ind + i].bits & CHUNK_MAP_ZEROED) == 0) {
memset((void*)(uintptr_t(chunk) + ((run_ind + i) << pagesize_2pow)),
0, pagesize);
- /* CHUNK_MAP_ZEROED is cleared below. */
+ // CHUNK_MAP_ZEROED is cleared below.
}
}
- /* Update dirty page accounting. */
+ // Update dirty page accounting.
if (chunk->map[run_ind + i].bits & CHUNK_MAP_DIRTY) {
chunk->ndirty--;
mNumDirty--;
- /* CHUNK_MAP_DIRTY is cleared below. */
+ // CHUNK_MAP_DIRTY is cleared below.
}
- /* Initialize the chunk map. */
+ // Initialize the chunk map.
if (aLarge) {
chunk->map[run_ind + i].bits = CHUNK_MAP_LARGE | CHUNK_MAP_ALLOCATED;
} else {
chunk->map[run_ind + i].bits = size_t(aRun) | CHUNK_MAP_ALLOCATED;
}
}
- /*
- * Set the run size only in the first element for large runs. This is
- * primarily a debugging aid, since the lack of size info for trailing
- * pages only matters if the application tries to operate on an
- * interior pointer.
- */
+ // Set the run size only in the first element for large runs. This is
+ // primarily a debugging aid, since the lack of size info for trailing
+ // pages only matters if the application tries to operate on an
+ // interior pointer.
if (aLarge) {
chunk->map[run_ind].bits |= aSize;
}
if (chunk->ndirty == 0 && old_ndirty > 0) {
mChunksDirty.Remove(chunk);
}
return true;
}
void
arena_t::InitChunk(arena_chunk_t* aChunk, bool aZeroed)
{
size_t i;
- /* WARNING: The following relies on !aZeroed meaning "used to be an arena
- * chunk".
- * When the chunk we're initializating as an arena chunk is zeroed, we
- * mark all runs are decommitted and zeroed.
- * When it is not, which we can assume means it's a recycled arena chunk,
- * all it can contain is an arena chunk header (which we're overwriting),
- * and zeroed or poisoned memory (because a recycled arena chunk will
- * have been emptied before being recycled). In that case, we can get
- * away with reusing the chunk as-is, marking all runs as madvised.
- */
+ // WARNING: The following relies on !aZeroed meaning "used to be an arena
+ // chunk".
+ // When the chunk we're initializating as an arena chunk is zeroed, we
+ // mark all runs are decommitted and zeroed.
+ // When it is not, which we can assume means it's a recycled arena chunk,
+ // all it can contain is an arena chunk header (which we're overwriting),
+ // and zeroed or poisoned memory (because a recycled arena chunk will
+ // have been emptied before being recycled). In that case, we can get
+ // away with reusing the chunk as-is, marking all runs as madvised.
+
size_t flags = aZeroed ? CHUNK_MAP_DECOMMITTED | CHUNK_MAP_ZEROED
: CHUNK_MAP_MADVISED;
mStats.mapped += chunksize;
aChunk->arena = this;
- /*
- * Claim that no pages are in use, since the header is merely overhead.
- */
+ // Claim that no pages are in use, since the header is merely overhead.
aChunk->ndirty = 0;
- /* Initialize the map to contain one maximal free untouched run. */
+ // Initialize the map to contain one maximal free untouched run.
#ifdef MALLOC_DECOMMIT
arena_run_t* run = (arena_run_t*)(uintptr_t(aChunk) +
(arena_chunk_header_npages << pagesize_2pow));
#endif
for (i = 0; i < arena_chunk_header_npages; i++) {
aChunk->map[i].bits = 0;
}
aChunk->map[i].bits = arena_maxclass | flags;
for (i++; i < chunk_npages-1; i++) {
aChunk->map[i].bits = flags;
}
aChunk->map[chunk_npages-1].bits = arena_maxclass | flags;
#ifdef MALLOC_DECOMMIT
- /*
- * Start out decommitted, in order to force a closer correspondence
- * between dirty pages and committed untouched pages.
- */
+ // Start out decommitted, in order to force a closer correspondence
+ // between dirty pages and committed untouched pages.
pages_decommit(run, arena_maxclass);
#endif
mStats.committed += arena_chunk_header_npages;
- /* Insert the run into the tree of available runs. */
+ // Insert the run into the tree of available runs.
mRunsAvail.Insert(&aChunk->map[arena_chunk_header_npages]);
#ifdef MALLOC_DOUBLE_PURGE
new (&aChunk->chunks_madvised_elem) mozilla::DoublyLinkedListElement<arena_chunk_t>();
#endif
}
void
@@ -2612,93 +2464,87 @@ arena_t::DeallocChunk(arena_chunk_t* aCh
}
#endif
chunk_dealloc((void*)mSpare, chunksize, ARENA_CHUNK);
mStats.mapped -= chunksize;
mStats.committed -= arena_chunk_header_npages;
}
- /*
- * Remove run from the tree of available runs, so that the arena does not use it.
- * Dirty page flushing only uses the tree of dirty chunks, so leaving this
- * chunk in the chunks_* trees is sufficient for that purpose.
- */
+ // Remove run from the tree of available runs, so that the arena does not use it.
+ // Dirty page flushing only uses the tree of dirty chunks, so leaving this
+ // chunk in the chunks_* trees is sufficient for that purpose.
mRunsAvail.Remove(&aChunk->map[arena_chunk_header_npages]);
mSpare = aChunk;
}
arena_run_t*
arena_t::AllocRun(arena_bin_t* aBin, size_t aSize, bool aLarge, bool aZero)
{
arena_run_t* run;
arena_chunk_map_t* mapelm;
arena_chunk_map_t key;
MOZ_ASSERT(aSize <= arena_maxclass);
MOZ_ASSERT((aSize & pagesize_mask) == 0);
- /* Search the arena's chunks for the lowest best fit. */
+ // Search the arena's chunks for the lowest best fit.
key.bits = aSize | CHUNK_MAP_KEY;
mapelm = mRunsAvail.SearchOrNext(&key);
if (mapelm) {
arena_chunk_t* chunk = GetChunkForPtr(mapelm);
size_t pageind = (uintptr_t(mapelm) - uintptr_t(chunk->map)) /
sizeof(arena_chunk_map_t);
run = (arena_run_t*)(uintptr_t(chunk) + (pageind << pagesize_2pow));
} else if (mSpare) {
- /* Use the spare. */
+ // Use the spare.
arena_chunk_t* chunk = mSpare;
mSpare = nullptr;
run = (arena_run_t*)(uintptr_t(chunk) + (arena_chunk_header_npages << pagesize_2pow));
- /* Insert the run into the tree of available runs. */
+ // Insert the run into the tree of available runs.
mRunsAvail.Insert(&chunk->map[arena_chunk_header_npages]);
} else {
- /*
- * No usable runs. Create a new chunk from which to allocate
- * the run.
- */
+ // No usable runs. Create a new chunk from which to allocate
+ // the run.
bool zeroed;
arena_chunk_t* chunk = (arena_chunk_t*)
chunk_alloc(chunksize, chunksize, false, &zeroed);
if (!chunk) {
return nullptr;
}
InitChunk(chunk, zeroed);
run = (arena_run_t*)(uintptr_t(chunk) + (arena_chunk_header_npages << pagesize_2pow));
}
- /* Update page map. */
+ // Update page map.
return SplitRun(run, aSize, aLarge, aZero) ? run : nullptr;
}
void
arena_t::Purge(bool aAll)
{
arena_chunk_t* chunk;
size_t i, npages;
- /* If all is set purge all dirty pages. */
+ // If all is set purge all dirty pages.
size_t dirty_max = aAll ? 1 : mMaxDirty;
#ifdef MOZ_DEBUG
size_t ndirty = 0;
for (auto chunk : mChunksDirty.iter()) {
ndirty += chunk->ndirty;
}
MOZ_ASSERT(ndirty == mNumDirty);
#endif
MOZ_DIAGNOSTIC_ASSERT(aAll || (mNumDirty > mMaxDirty));
- /*
- * Iterate downward through chunks until enough dirty memory has been
- * purged. Terminate as soon as possible in order to minimize the
- * number of system calls, even if a chunk has only been partially
- * purged.
- */
+ // Iterate downward through chunks until enough dirty memory has been
+ // purged. Terminate as soon as possible in order to minimize the
+ // number of system calls, even if a chunk has only been partially
+ // purged.
while (mNumDirty > (dirty_max >> 1)) {
#ifdef MALLOC_DOUBLE_PURGE
bool madvised = false;
#endif
chunk = mChunksDirty.Last();
MOZ_DIAGNOSTIC_ASSERT(chunk);
for (i = chunk_npages - 1; chunk->ndirty > 0; i--) {
@@ -2708,17 +2554,17 @@ arena_t::Purge(bool aAll)
#ifdef MALLOC_DECOMMIT
const size_t free_operation = CHUNK_MAP_DECOMMITTED;
#else
const size_t free_operation = CHUNK_MAP_MADVISED;
#endif
MOZ_ASSERT((chunk->map[i].bits &
CHUNK_MAP_MADVISED_OR_DECOMMITTED) == 0);
chunk->map[i].bits ^= free_operation | CHUNK_MAP_DIRTY;
- /* Find adjacent dirty run(s). */
+ // Find adjacent dirty run(s).
for (npages = 1;
i > arena_chunk_header_npages &&
(chunk->map[i - 1].bits & CHUNK_MAP_DIRTY);
npages++) {
i--;
MOZ_ASSERT((chunk->map[i].bits &
CHUNK_MAP_MADVISED_OR_DECOMMITTED) == 0);
chunk->map[i].bits ^= free_operation | CHUNK_MAP_DIRTY;
@@ -2745,18 +2591,18 @@ arena_t::Purge(bool aAll)
}
}
if (chunk->ndirty == 0) {
mChunksDirty.Remove(chunk);
}
#ifdef MALLOC_DOUBLE_PURGE
if (madvised) {
- /* The chunk might already be in the list, but this
- * makes sure it's at the front. */
+ // The chunk might already be in the list, but this
+ // makes sure it's at the front.
if (mChunksMAdvised.ElementProbablyInList(chunk)) {
mChunksMAdvised.remove(chunk);
}
mChunksMAdvised.pushFront(chunk);
}
#endif
}
}
@@ -2773,17 +2619,17 @@ arena_t::DallocRun(arena_run_t* aRun, bo
MOZ_DIAGNOSTIC_ASSERT(run_ind < chunk_npages);
if ((chunk->map[run_ind].bits & CHUNK_MAP_LARGE) != 0) {
size = chunk->map[run_ind].bits & ~pagesize_mask;
} else {
size = aRun->bin->run_size;
}
run_pages = (size >> pagesize_2pow);
- /* Mark pages as unallocated in the chunk map. */
+ // Mark pages as unallocated in the chunk map.
if (aDirty) {
size_t i;
for (i = 0; i < run_pages; i++) {
MOZ_DIAGNOSTIC_ASSERT((chunk->map[run_ind + i].bits & CHUNK_MAP_DIRTY)
== 0);
chunk->map[run_ind + i].bits = CHUNK_MAP_DIRTY;
}
@@ -2801,91 +2647,85 @@ arena_t::DallocRun(arena_run_t* aRun, bo
CHUNK_MAP_ALLOCATED);
}
}
chunk->map[run_ind].bits = size | (chunk->map[run_ind].bits &
pagesize_mask);
chunk->map[run_ind+run_pages-1].bits = size |
(chunk->map[run_ind+run_pages-1].bits & pagesize_mask);
- /* Try to coalesce forward. */
+ // Try to coalesce forward.
if (run_ind + run_pages < chunk_npages &&
(chunk->map[run_ind+run_pages].bits & CHUNK_MAP_ALLOCATED) == 0) {
size_t nrun_size = chunk->map[run_ind+run_pages].bits &
~pagesize_mask;
- /*
- * Remove successor from tree of available runs; the coalesced run is
- * inserted later.
- */
+ // Remove successor from tree of available runs; the coalesced run is
+ // inserted later.
mRunsAvail.Remove(&chunk->map[run_ind+run_pages]);
size += nrun_size;
run_pages = size >> pagesize_2pow;
MOZ_DIAGNOSTIC_ASSERT((chunk->map[run_ind+run_pages-1].bits & ~pagesize_mask)
== nrun_size);
chunk->map[run_ind].bits = size | (chunk->map[run_ind].bits &
pagesize_mask);
chunk->map[run_ind+run_pages-1].bits = size |
(chunk->map[run_ind+run_pages-1].bits & pagesize_mask);
}
- /* Try to coalesce backward. */
+ // Try to coalesce backward.
if (run_ind > arena_chunk_header_npages && (chunk->map[run_ind-1].bits &
CHUNK_MAP_ALLOCATED) == 0) {
size_t prun_size = chunk->map[run_ind-1].bits & ~pagesize_mask;
run_ind -= prun_size >> pagesize_2pow;
- /*
- * Remove predecessor from tree of available runs; the coalesced run is
- * inserted later.
- */
+ // Remove predecessor from tree of available runs; the coalesced run is
+ // inserted later.
mRunsAvail.Remove(&chunk->map[run_ind]);
size += prun_size;
run_pages = size >> pagesize_2pow;
MOZ_DIAGNOSTIC_ASSERT((chunk->map[run_ind].bits & ~pagesize_mask) ==
prun_size);
chunk->map[run_ind].bits = size | (chunk->map[run_ind].bits &
pagesize_mask);
chunk->map[run_ind+run_pages-1].bits = size |
(chunk->map[run_ind+run_pages-1].bits & pagesize_mask);
}
- /* Insert into tree of available runs, now that coalescing is complete. */
+ // Insert into tree of available runs, now that coalescing is complete.
mRunsAvail.Insert(&chunk->map[run_ind]);
- /* Deallocate chunk if it is now completely unused. */
+ // Deallocate chunk if it is now completely unused.
if ((chunk->map[arena_chunk_header_npages].bits & (~pagesize_mask |
CHUNK_MAP_ALLOCATED)) == arena_maxclass) {
DeallocChunk(chunk);
}
- /* Enforce mMaxDirty. */
+ // Enforce mMaxDirty.
if (mNumDirty > mMaxDirty) {
Purge(false);
}
}
void
arena_t::TrimRunHead(arena_chunk_t* aChunk, arena_run_t* aRun, size_t aOldSize,
size_t aNewSize)
{
size_t pageind = (uintptr_t(aRun) - uintptr_t(aChunk)) >> pagesize_2pow;
size_t head_npages = (aOldSize - aNewSize) >> pagesize_2pow;
MOZ_ASSERT(aOldSize > aNewSize);
- /*
- * Update the chunk map so that arena_t::RunDalloc() can treat the
- * leading run as separately allocated.
- */
+ // Update the chunk map so that arena_t::RunDalloc() can treat the
+ // leading run as separately allocated.
aChunk->map[pageind].bits = (aOldSize - aNewSize) | CHUNK_MAP_LARGE |
CHUNK_MAP_ALLOCATED;
aChunk->map[pageind+head_npages].bits = aNewSize | CHUNK_MAP_LARGE |
CHUNK_MAP_ALLOCATED;
DallocRun(aRun, false);
}
@@ -2893,170 +2733,160 @@ void
arena_t::TrimRunTail(arena_chunk_t* aChunk, arena_run_t* aRun, size_t aOldSize,
size_t aNewSize, bool aDirty)
{
size_t pageind = (uintptr_t(aRun) - uintptr_t(aChunk)) >> pagesize_2pow;
size_t npages = aNewSize >> pagesize_2pow;
MOZ_ASSERT(aOldSize > aNewSize);
- /*
- * Update the chunk map so that arena_t::RunDalloc() can treat the
- * trailing run as separately allocated.
- */
+ // Update the chunk map so that arena_t::RunDalloc() can treat the
+ // trailing run as separately allocated.
aChunk->map[pageind].bits = aNewSize | CHUNK_MAP_LARGE |
CHUNK_MAP_ALLOCATED;
aChunk->map[pageind+npages].bits = (aOldSize - aNewSize) | CHUNK_MAP_LARGE
| CHUNK_MAP_ALLOCATED;
DallocRun((arena_run_t*)(uintptr_t(aRun) + aNewSize), aDirty);
}
arena_run_t*
arena_t::GetNonFullBinRun(arena_bin_t* aBin)
{
arena_chunk_map_t* mapelm;
arena_run_t* run;
unsigned i, remainder;
- /* Look for a usable run. */
+ // Look for a usable run.
mapelm = aBin->runs.First();
if (mapelm) {
- /* run is guaranteed to have available space. */
+ // run is guaranteed to have available space.
aBin->runs.Remove(mapelm);
run = (arena_run_t*)(mapelm->bits & ~pagesize_mask);
return run;
}
- /* No existing runs have any space available. */
-
- /* Allocate a new run. */
+ // No existing runs have any space available.
+
+ // Allocate a new run.
run = AllocRun(aBin, aBin->run_size, false, false);
if (!run) {
return nullptr;
}
- /*
- * Don't initialize if a race in arena_t::RunAlloc() allowed an existing
- * run to become usable.
- */
+ // Don't initialize if a race in arena_t::RunAlloc() allowed an existing
+ // run to become usable.
if (run == aBin->runcur) {
return run;
}
- /* Initialize run internals. */
+ // Initialize run internals.
run->bin = aBin;
for (i = 0; i < aBin->regs_mask_nelms - 1; i++) {
run->regs_mask[i] = UINT_MAX;
}
remainder = aBin->nregs & ((1U << (SIZEOF_INT_2POW + 3)) - 1);
if (remainder == 0) {
run->regs_mask[i] = UINT_MAX;
} else {
- /* The last element has spare bits that need to be unset. */
+ // The last element has spare bits that need to be unset.
run->regs_mask[i] = (UINT_MAX >> ((1U << (SIZEOF_INT_2POW + 3))
- remainder));
}
run->regs_minelm = 0;
run->nfree = aBin->nregs;
#if defined(MOZ_DEBUG) || defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED)
run->magic = ARENA_RUN_MAGIC;
#endif
aBin->stats.curruns++;
return run;
}
-/* bin->runcur must have space available before this function is called. */
+// bin->runcur must have space available before this function is called.
void*
arena_t::MallocBinEasy(arena_bin_t* aBin, arena_run_t* aRun)
{
void* ret;
MOZ_DIAGNOSTIC_ASSERT(aRun->magic == ARENA_RUN_MAGIC);
MOZ_DIAGNOSTIC_ASSERT(aRun->nfree > 0);
ret = arena_run_reg_alloc(aRun, aBin);
MOZ_DIAGNOSTIC_ASSERT(ret);
aRun->nfree--;
return ret;
}
-/* Re-fill aBin->runcur, then call arena_t::MallocBinEasy(). */
+// Re-fill aBin->runcur, then call arena_t::MallocBinEasy().
void*
arena_t::MallocBinHard(arena_bin_t* aBin)
{
aBin->runcur = GetNonFullBinRun(aBin);
if (!aBin->runcur) {
return nullptr;
}
MOZ_DIAGNOSTIC_ASSERT(aBin->runcur->magic == ARENA_RUN_MAGIC);
MOZ_DIAGNOSTIC_ASSERT(aBin->runcur->nfree > 0);
return MallocBinEasy(aBin, aBin->runcur);
}
-/*
- * Calculate bin->run_size such that it meets the following constraints:
- *
- * *) bin->run_size >= min_run_size
- * *) bin->run_size <= arena_maxclass
- * *) bin->run_size <= RUN_MAX_SMALL
- * *) run header overhead <= RUN_MAX_OVRHD (or header overhead relaxed).
- *
- * bin->nregs, bin->regs_mask_nelms, and bin->reg0_offset are
- * also calculated here, since these settings are all interdependent.
- */
+// Calculate bin->run_size such that it meets the following constraints:
+//
+// *) bin->run_size >= min_run_size
+// *) bin->run_size <= arena_maxclass
+// *) bin->run_size <= RUN_MAX_SMALL
+// *) run header overhead <= RUN_MAX_OVRHD (or header overhead relaxed).
+//
+// bin->nregs, bin->regs_mask_nelms, and bin->reg0_offset are
+// also calculated here, since these settings are all interdependent.
static size_t
arena_bin_run_size_calc(arena_bin_t *bin, size_t min_run_size)
{
size_t try_run_size, good_run_size;
unsigned good_nregs, good_mask_nelms, good_reg0_offset;
unsigned try_nregs, try_mask_nelms, try_reg0_offset;
MOZ_ASSERT(min_run_size >= pagesize);
MOZ_ASSERT(min_run_size <= arena_maxclass);
- /*
- * Calculate known-valid settings before entering the run_size
- * expansion loop, so that the first part of the loop always copies
- * valid settings.
- *
- * The do..while loop iteratively reduces the number of regions until
- * the run header and the regions no longer overlap. A closed formula
- * would be quite messy, since there is an interdependency between the
- * header's mask length and the number of regions.
- */
+ // Calculate known-valid settings before entering the run_size
+ // expansion loop, so that the first part of the loop always copies
+ // valid settings.
+ //
+ // The do..while loop iteratively reduces the number of regions until
+ // the run header and the regions no longer overlap. A closed formula
+ // would be quite messy, since there is an interdependency between the
+ // header's mask length and the number of regions.
try_run_size = min_run_size;
try_nregs = ((try_run_size - sizeof(arena_run_t)) / bin->reg_size)
- + 1; /* Counter-act try_nregs-- in loop. */
+ + 1; // Counter-act try_nregs-- in loop.
do {
try_nregs--;
try_mask_nelms = (try_nregs >> (SIZEOF_INT_2POW + 3)) +
((try_nregs & ((1U << (SIZEOF_INT_2POW + 3)) - 1)) ? 1 : 0);
try_reg0_offset = try_run_size - (try_nregs * bin->reg_size);
} while (sizeof(arena_run_t) + (sizeof(unsigned) * (try_mask_nelms - 1))
> try_reg0_offset);
- /* run_size expansion loop. */
+ // run_size expansion loop.
do {
- /*
- * Copy valid settings before trying more aggressive settings.
- */
+ // Copy valid settings before trying more aggressive settings.
good_run_size = try_run_size;
good_nregs = try_nregs;
good_mask_nelms = try_mask_nelms;
good_reg0_offset = try_reg0_offset;
- /* Try more aggressive settings. */
+ // Try more aggressive settings.
try_run_size += pagesize;
try_nregs = ((try_run_size - sizeof(arena_run_t)) /
- bin->reg_size) + 1; /* Counter-act try_nregs-- in loop. */
+ bin->reg_size) + 1; // Counter-act try_nregs-- in loop.
do {
try_nregs--;
try_mask_nelms = (try_nregs >> (SIZEOF_INT_2POW + 3)) +
((try_nregs & ((1U << (SIZEOF_INT_2POW + 3)) - 1)) ?
1 : 0);
try_reg0_offset = try_run_size - (try_nregs *
bin->reg_size);
} while (sizeof(arena_run_t) + (sizeof(unsigned) *
@@ -3064,50 +2894,49 @@ arena_bin_run_size_calc(arena_bin_t *bin
} while (try_run_size <= arena_maxclass
&& RUN_MAX_OVRHD * (bin->reg_size << 3) > RUN_MAX_OVRHD_RELAX
&& (try_reg0_offset << RUN_BFP) > RUN_MAX_OVRHD * try_run_size);
MOZ_ASSERT(sizeof(arena_run_t) + (sizeof(unsigned) * (good_mask_nelms - 1))
<= good_reg0_offset);
MOZ_ASSERT((good_mask_nelms << (SIZEOF_INT_2POW + 3)) >= good_nregs);
- /* Copy final settings. */
+ // Copy final settings.
bin->run_size = good_run_size;
bin->nregs = good_nregs;
bin->regs_mask_nelms = good_mask_nelms;
bin->reg0_offset = good_reg0_offset;
return good_run_size;
}
void*
arena_t::MallocSmall(size_t aSize, bool aZero)
{
void* ret;
arena_bin_t* bin;
arena_run_t* run;
if (aSize < small_min) {
- /* Tiny. */
+ // Tiny.
aSize = pow2_ceil(aSize);
bin = &mBins[ffs((int)(aSize >> (TINY_MIN_2POW + 1)))];
- /*
- * Bin calculation is always correct, but we may need
- * to fix size for the purposes of assertions and/or
- * stats accuracy.
- */
+
+ // Bin calculation is always correct, but we may need
+ // to fix size for the purposes of assertions and/or
+ // stats accuracy.
if (aSize < (1U << TINY_MIN_2POW)) {
aSize = 1U << TINY_MIN_2POW;
}
} else if (aSize <= small_max) {
- /* Quantum-spaced. */
+ // Quantum-spaced.
aSize = QUANTUM_CEILING(aSize);
bin = &mBins[ntbins + (aSize >> QUANTUM_2POW_MIN) - 1];
} else {
- /* Sub-page. */
+ // Sub-page.
aSize = pow2_ceil(aSize);
bin = &mBins[ntbins + nqbins
+ (ffs((int)(aSize >> SMALL_MAX_2POW_DEFAULT)) - 2)];
}
MOZ_DIAGNOSTIC_ASSERT(aSize == bin->reg_size);
{
MutexAutoLock lock(mLock);
@@ -3137,17 +2966,17 @@ arena_t::MallocSmall(size_t aSize, bool
return ret;
}
void*
arena_t::MallocLarge(size_t aSize, bool aZero)
{
void* ret;
- /* Large allocation. */
+ // Large allocation.
aSize = PAGE_CEILING(aSize);
{
MutexAutoLock lock(mLock);
ret = AllocRun(nullptr, aSize, true, aZero);
if (!ret) {
return nullptr;
}
@@ -3183,17 +3012,17 @@ imalloc(size_t aSize, bool aZero, arena_
if (aSize <= arena_maxclass) {
aArena = aArena ? aArena : choose_arena(aSize);
return aArena->Malloc(aSize, aZero);
}
return huge_malloc(aSize, aZero);
}
-/* Only handles large allocations that require more than page alignment. */
+// Only handles large allocations that require more than page alignment.
void*
arena_t::Palloc(size_t aAlignment, size_t aSize, size_t aAllocSize)
{
void* ret;
size_t offset;
arena_chunk_t* chunk;
MOZ_ASSERT((aSize & pagesize_mask) == 0);
@@ -3219,17 +3048,17 @@ arena_t::Palloc(size_t aAlignment, size_
leadsize = aAlignment - offset;
if (leadsize > 0) {
TrimRunHead(chunk, (arena_run_t*)ret, aAllocSize, aAllocSize - leadsize);
ret = (void*)(uintptr_t(ret) + leadsize);
}
trailsize = aAllocSize - leadsize - aSize;
if (trailsize != 0) {
- /* Trim trailing space. */
+ // Trim trailing space.
MOZ_ASSERT(trailsize < aAllocSize);
TrimRunTail(chunk, (arena_run_t*)ret, aSize + trailsize, aSize, false);
}
}
mStats.allocated_large += aSize;
}
@@ -3242,90 +3071,80 @@ arena_t::Palloc(size_t aAlignment, size_
}
static inline void*
ipalloc(size_t aAlignment, size_t aSize, arena_t* aArena)
{
void* ret;
size_t ceil_size;
- /*
- * Round size up to the nearest multiple of alignment.
- *
- * This done, we can take advantage of the fact that for each small
- * size class, every object is aligned at the smallest power of two
- * that is non-zero in the base two representation of the size. For
- * example:
- *
- * Size | Base 2 | Minimum alignment
- * -----+----------+------------------
- * 96 | 1100000 | 32
- * 144 | 10100000 | 32
- * 192 | 11000000 | 64
- *
- * Depending on runtime settings, it is possible that arena_malloc()
- * will further round up to a power of two, but that never causes
- * correctness issues.
- */
+ // Round size up to the nearest multiple of alignment.
+ //
+ // This done, we can take advantage of the fact that for each small
+ // size class, every object is aligned at the smallest power of two
+ // that is non-zero in the base two representation of the size. For
+ // example:
+ //
+ // Size | Base 2 | Minimum alignment
+ // -----+----------+------------------
+ // 96 | 1100000 | 32
+ // 144 | 10100000 | 32
+ // 192 | 11000000 | 64
+ //
+ // Depending on runtime settings, it is possible that arena_malloc()
+ // will further round up to a power of two, but that never causes
+ // correctness issues.
ceil_size = ALIGNMENT_CEILING(aSize, aAlignment);
- /*
- * (ceil_size < aSize) protects against the combination of maximal
- * alignment and size greater than maximal alignment.
- */
+
+ // (ceil_size < aSize) protects against the combination of maximal
+ // alignment and size greater than maximal alignment.
if (ceil_size < aSize) {
- /* size_t overflow. */
+ // size_t overflow.
return nullptr;
}
if (ceil_size <= pagesize || (aAlignment <= pagesize
&& ceil_size <= arena_maxclass)) {
aArena = aArena ? aArena : choose_arena(aSize);
ret = aArena->Malloc(ceil_size, false);
} else {
size_t run_size;
- /*
- * We can't achieve sub-page alignment, so round up alignment
- * permanently; it makes later calculations simpler.
- */
+ // We can't achieve sub-page alignment, so round up alignment
+ // permanently; it makes later calculations simpler.
aAlignment = PAGE_CEILING(aAlignment);
ceil_size = PAGE_CEILING(aSize);
- /*
- * (ceil_size < aSize) protects against very large sizes within
- * pagesize of SIZE_T_MAX.
- *
- * (ceil_size + aAlignment < ceil_size) protects against the
- * combination of maximal alignment and ceil_size large enough
- * to cause overflow. This is similar to the first overflow
- * check above, but it needs to be repeated due to the new
- * ceil_size value, which may now be *equal* to maximal
- * alignment, whereas before we only detected overflow if the
- * original size was *greater* than maximal alignment.
- */
+
+ // (ceil_size < aSize) protects against very large sizes within
+ // pagesize of SIZE_T_MAX.
+ //
+ // (ceil_size + aAlignment < ceil_size) protects against the
+ // combination of maximal alignment and ceil_size large enough
+ // to cause overflow. This is similar to the first overflow
+ // check above, but it needs to be repeated due to the new
+ // ceil_size value, which may now be *equal* to maximal
+ // alignment, whereas before we only detected overflow if the
+ // original size was *greater* than maximal alignment.
if (ceil_size < aSize || ceil_size + aAlignment < ceil_size) {
- /* size_t overflow. */
+ // size_t overflow.
return nullptr;
}
- /*
- * Calculate the size of the over-size run that arena_palloc()
- * would need to allocate in order to guarantee the alignment.
- */
+ // Calculate the size of the over-size run that arena_palloc()
+ // would need to allocate in order to guarantee the alignment.
if (ceil_size >= aAlignment) {
run_size = ceil_size + aAlignment - pagesize;
} else {
- /*
- * It is possible that (aAlignment << 1) will cause
- * overflow, but it doesn't matter because we also
- * subtract pagesize, which in the case of overflow
- * leaves us with a very large run_size. That causes
- * the first conditional below to fail, which means
- * that the bogus run_size value never gets used for
- * anything important.
- */
+ // It is possible that (aAlignment << 1) will cause
+ // overflow, but it doesn't matter because we also
+ // subtract pagesize, which in the case of overflow
+ // leaves us with a very large run_size. That causes
+ // the first conditional below to fail, which means
+ // that the bogus run_size value never gets used for
+ // anything important.
run_size = (aAlignment << 1) - pagesize;
}
if (run_size <= arena_maxclass) {
aArena = aArena ? aArena : choose_arena(aSize);
ret = aArena->Palloc(aAlignment, ceil_size, run_size);
} else if (aAlignment <= chunksize) {
ret = huge_malloc(ceil_size, false);
@@ -3333,17 +3152,17 @@ ipalloc(size_t aAlignment, size_t aSize,
ret = huge_palloc(ceil_size, aAlignment, false);
}
}
MOZ_ASSERT((uintptr_t(ret) & (aAlignment - 1)) == 0);
return ret;
}
-/* Return the size of the allocation pointed to by ptr. */
+// Return the size of the allocation pointed to by ptr.
static size_t
arena_salloc(const void *ptr)
{
size_t ret;
arena_chunk_t *chunk;
size_t pageind, mapbits;
MOZ_ASSERT(ptr);
@@ -3360,28 +3179,26 @@ arena_salloc(const void *ptr)
} else {
ret = mapbits & ~pagesize_mask;
MOZ_DIAGNOSTIC_ASSERT(ret != 0);
}
return ret;
}
-/*
- * Validate ptr before assuming that it points to an allocation. Currently,
- * the following validation is performed:
- *
- * + Check that ptr is not nullptr.
- *
- * + Check that ptr lies within a mapped chunk.
- */
+// Validate ptr before assuming that it points to an allocation. Currently,
+// the following validation is performed:
+//
+// + Check that ptr is not nullptr.
+//
+// + Check that ptr lies within a mapped chunk.
static inline size_t
isalloc_validate(const void* aPtr)
{
- /* If the allocator is not initialized, the pointer can't belong to it. */
+ // If the allocator is not initialized, the pointer can't belong to it.
if (malloc_initialized == false) {
return 0;
}
auto chunk = GetChunkForPtr(aPtr);
if (!chunk) {
return 0;
}
@@ -3392,46 +3209,45 @@ isalloc_validate(const void* aPtr)
if (chunk != aPtr) {
MOZ_DIAGNOSTIC_ASSERT(chunk->arena->mMagic == ARENA_MAGIC);
return arena_salloc(aPtr);
}
extent_node_t key;
- /* Chunk. */
+ // Chunk.
key.addr = (void*)chunk;
MutexAutoLock lock(huge_mtx);
extent_node_t* node = huge.Search(&key);
if (node) {
return node->size;
}
return 0;
}
static inline size_t
isalloc(const void* aPtr)
{
MOZ_ASSERT(aPtr);
auto chunk = GetChunkForPtr(aPtr);
if (chunk != aPtr) {
- /* Region. */
+ // Region.
MOZ_ASSERT(chunk->arena->mMagic == ARENA_MAGIC);
return arena_salloc(aPtr);
}
extent_node_t key;
- /* Chunk (huge allocation). */
-
+ // Chunk (huge allocation).
MutexAutoLock lock(huge_mtx);
- /* Extract from tree of huge allocations. */
+ // Extract from tree of huge allocations.
key.addr = const_cast<void*>(aPtr);
extent_node_t* node = huge.Search(&key);
MOZ_DIAGNOSTIC_ASSERT(node);
return node->size;
}
template<> inline void
@@ -3506,17 +3322,16 @@ MozJemalloc::jemalloc_ptr_info(const voi
while (true) {
size = mapbits & ~pagesize_mask;
if (size != 0) {
break;
}
// The following two return paths shouldn't occur in
// practice unless there is heap corruption.
-
pageind--;
MOZ_DIAGNOSTIC_ASSERT(pageind >= arena_chunk_header_npages);
if (pageind < arena_chunk_header_npages) {
*aInfo = { TagUnknown, nullptr, 0 };
return;
}
mapbits = chunk->map[pageind].bits;
@@ -3528,17 +3343,16 @@ MozJemalloc::jemalloc_ptr_info(const voi
}
void* addr = ((char*)chunk) + (pageind << pagesize_2pow);
*aInfo = { TagLiveLarge, addr, size };
return;
}
// It must be a small allocation.
-
auto run = (arena_run_t *)(mapbits & ~pagesize_mask);
MOZ_DIAGNOSTIC_ASSERT(run->magic == ARENA_RUN_MAGIC);
// The allocation size is stored in the run metadata.
size_t size = run->bin->reg_size;
// Address of the first possible pointer in the run after its headers.
uintptr_t reg0_addr = (uintptr_t)run + run->bin->reg0_offset;
@@ -3590,50 +3404,47 @@ arena_t::DallocSmall(arena_chunk_t* aChu
MOZ_DIAGNOSTIC_ASSERT((uintptr_t(aPtr) - (uintptr_t(run) + bin->reg0_offset)) % size == 0);
memset(aPtr, kAllocPoison, size);
arena_run_reg_dalloc(run, bin, aPtr, size);
run->nfree++;
if (run->nfree == bin->nregs) {
- /* Deallocate run. */
+ // Deallocate run.
if (run == bin->runcur) {
bin->runcur = nullptr;
} else if (bin->nregs != 1) {
size_t run_pageind = (uintptr_t(run) - uintptr_t(aChunk)) >> pagesize_2pow;
arena_chunk_map_t* run_mapelm = &aChunk->map[run_pageind];
- /*
- * This block's conditional is necessary because if the
- * run only contains one region, then it never gets
- * inserted into the non-full runs tree.
- */
+
+ // This block's conditional is necessary because if the
+ // run only contains one region, then it never gets
+ // inserted into the non-full runs tree.
MOZ_DIAGNOSTIC_ASSERT(bin->runs.Search(run_mapelm) == run_mapelm);
bin->runs.Remove(run_mapelm);
}
#if defined(MOZ_DEBUG) || defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED)
run->magic = 0;
#endif
DallocRun(run, true);
bin->stats.curruns--;
} else if (run->nfree == 1 && run != bin->runcur) {
- /*
- * Make sure that bin->runcur always refers to the lowest
- * non-full run, if one exists.
- */
+ // Make sure that bin->runcur always refers to the lowest
+ // non-full run, if one exists.
if (!bin->runcur) {
bin->runcur = run;
} else if (uintptr_t(run) < uintptr_t(bin->runcur)) {
- /* Switch runcur. */
+ // Switch runcur.
if (bin->runcur->nfree > 0) {
arena_chunk_t* runcur_chunk = GetChunkForPtr(bin->runcur);
size_t runcur_pageind = (uintptr_t(bin->runcur) - uintptr_t(runcur_chunk)) >> pagesize_2pow;
arena_chunk_map_t* runcur_mapelm = &runcur_chunk->map[runcur_pageind];
- /* Insert runcur. */
+ // Insert runcur.
MOZ_DIAGNOSTIC_ASSERT(!bin->runs.Search(runcur_mapelm));
bin->runs.Insert(runcur_mapelm);
}
bin->runcur = run;
} else {
size_t run_pageind = (uintptr_t(run) - uintptr_t(aChunk)) >> pagesize_2pow;
arena_chunk_map_t *run_mapelm = &aChunk->map[run_pageind];
@@ -3669,20 +3480,20 @@ arena_dalloc(void* aPtr, size_t aOffset)
MOZ_ASSERT(arena);
MOZ_DIAGNOSTIC_ASSERT(arena->mMagic == ARENA_MAGIC);
MutexAutoLock lock(arena->mLock);
size_t pageind = aOffset >> pagesize_2pow;
arena_chunk_map_t* mapelm = &chunk->map[pageind];
MOZ_DIAGNOSTIC_ASSERT((mapelm->bits & CHUNK_MAP_ALLOCATED) != 0);
if ((mapelm->bits & CHUNK_MAP_LARGE) == 0) {
- /* Small allocation. */
+ // Small allocation.
arena->DallocSmall(chunk, aPtr, mapelm);
} else {
- /* Large allocation. */
+ // Large allocation.
arena->DallocLarge(chunk, aPtr);
}
}
static inline void
idalloc(void *ptr)
{
size_t offset;
@@ -3698,46 +3509,42 @@ idalloc(void *ptr)
}
void
arena_t::RallocShrinkLarge(arena_chunk_t* aChunk, void* aPtr, size_t aSize,
size_t aOldSize)
{
MOZ_ASSERT(aSize < aOldSize);
- /*
- * Shrink the run, and make trailing pages available for other
- * allocations.
- */
+ // Shrink the run, and make trailing pages available for other
+ // allocations.
MutexAutoLock lock(mLock);
TrimRunTail(aChunk, (arena_run_t*)aPtr, aOldSize, aSize, true);
mStats.allocated_large -= aOldSize - aSize;
}
-/* Returns whether reallocation was successful. */
+// Returns whether reallocation was successful.
bool
arena_t::RallocGrowLarge(arena_chunk_t* aChunk, void* aPtr, size_t aSize,
size_t aOldSize)
{
size_t pageind = (uintptr_t(aPtr) - uintptr_t(aChunk)) >> pagesize_2pow;
size_t npages = aOldSize >> pagesize_2pow;
MutexAutoLock lock(mLock);
MOZ_DIAGNOSTIC_ASSERT(aOldSize == (aChunk->map[pageind].bits & ~pagesize_mask));
- /* Try to extend the run. */
+ // Try to extend the run.
MOZ_ASSERT(aSize > aOldSize);
if (pageind + npages < chunk_npages && (aChunk->map[pageind+npages].bits
& CHUNK_MAP_ALLOCATED) == 0 && (aChunk->map[pageind+npages].bits &
~pagesize_mask) >= aSize - aOldSize) {
- /*
- * The next run is available and sufficiently large. Split the
- * following run, then merge the first part with the existing
- * allocation.
- */
+ // The next run is available and sufficiently large. Split the
+ // following run, then merge the first part with the existing
+ // allocation.
if (!SplitRun((arena_run_t*)(uintptr_t(aChunk) +
((pageind + npages) << pagesize_2pow)),
aSize - aOldSize,
true,
false)) {
return false;
}
@@ -3748,41 +3555,39 @@ arena_t::RallocGrowLarge(arena_chunk_t*
mStats.allocated_large += aSize - aOldSize;
return true;
}
return false;
}
-/*
- * Try to resize a large allocation, in order to avoid copying. This will
- * always fail if growing an object, and the following run is already in use.
- * Returns whether reallocation was successful.
- */
+// Try to resize a large allocation, in order to avoid copying. This will
+// always fail if growing an object, and the following run is already in use.
+// Returns whether reallocation was successful.
static bool
arena_ralloc_large(void* aPtr, size_t aSize, size_t aOldSize)
{
size_t psize;
psize = PAGE_CEILING(aSize);
if (psize == aOldSize) {
- /* Same size class. */
+ // Same size class.
if (aSize < aOldSize) {
memset((void*)((uintptr_t)aPtr + aSize), kAllocPoison, aOldSize - aSize);
}
return true;
}
arena_chunk_t* chunk = GetChunkForPtr(aPtr);
arena_t* arena = chunk->arena;
MOZ_DIAGNOSTIC_ASSERT(arena->mMagic == ARENA_MAGIC);
if (psize < aOldSize) {
- /* Fill before shrinking in order avoid a race. */
+ // Fill before shrinking in order avoid a race.
memset((void*)((uintptr_t)aPtr + aSize), kAllocPoison, aOldSize - aSize);
arena->RallocShrinkLarge(chunk, aPtr, psize, aOldSize);
return true;
}
bool ret = arena->RallocGrowLarge(chunk, aPtr, psize, aOldSize);
if (ret && opt_zero) {
memset((void*)((uintptr_t)aPtr + aOldSize), 0, aSize - aOldSize);
@@ -3791,53 +3596,51 @@ arena_ralloc_large(void* aPtr, size_t aS
}
static void*
arena_ralloc(void* aPtr, size_t aSize, size_t aOldSize, arena_t* aArena)
{
void* ret;
size_t copysize;
- /* Try to avoid moving the allocation. */
+ // Try to avoid moving the allocation.
if (aSize < small_min) {
if (aOldSize < small_min &&
ffs((int)(pow2_ceil(aSize) >> (TINY_MIN_2POW + 1))) ==
ffs((int)(pow2_ceil(aOldSize) >> (TINY_MIN_2POW + 1)))) {
- goto IN_PLACE; /* Same size class. */
+ goto IN_PLACE; // Same size class.
}
} else if (aSize <= small_max) {
if (aOldSize >= small_min && aOldSize <= small_max &&
(QUANTUM_CEILING(aSize) >> QUANTUM_2POW_MIN) ==
(QUANTUM_CEILING(aOldSize) >> QUANTUM_2POW_MIN)) {
- goto IN_PLACE; /* Same size class. */
+ goto IN_PLACE; // Same size class.
}
} else if (aSize <= bin_maxclass) {
if (aOldSize > small_max && aOldSize <= bin_maxclass &&
pow2_ceil(aSize) == pow2_ceil(aOldSize)) {
- goto IN_PLACE; /* Same size class. */
+ goto IN_PLACE; // Same size class.
}
} else if (aOldSize > bin_maxclass && aOldSize <= arena_maxclass) {
MOZ_ASSERT(aSize > bin_maxclass);
if (arena_ralloc_large(aPtr, aSize, aOldSize)) {
return aPtr;
}
}
- /*
- * If we get here, then aSize and aOldSize are different enough that we
- * need to move the object. In that case, fall back to allocating new
- * space and copying.
- */
+ // If we get here, then aSize and aOldSize are different enough that we
+ // need to move the object. In that case, fall back to allocating new
+ // space and copying.
aArena = aArena ? aArena : choose_arena(aSize);
ret = aArena->Malloc(aSize, false);
if (!ret) {
return nullptr;
}
- /* Junk/zero-filling were already done by arena_t::Malloc(). */
+ // Junk/zero-filling were already done by arena_t::Malloc().
copysize = (aSize < aOldSize) ? aSize : aOldSize;
#ifdef VM_COPY_MIN
if (copysize >= VM_COPY_MIN) {
pages_copy(ret, aPtr, copysize);
} else
#endif
{
memcpy(ret, aPtr, copysize);
@@ -3877,60 +3680,60 @@ arena_t::Init()
if (!mLock.Init()) {
return false;
}
memset(&mLink, 0, sizeof(mLink));
memset(&mStats, 0, sizeof(arena_stats_t));
- /* Initialize chunks. */
+ // Initialize chunks.
mChunksDirty.Init();
#ifdef MALLOC_DOUBLE_PURGE
new (&mChunksMAdvised) mozilla::DoublyLinkedList<arena_chunk_t>();
#endif
mSpare = nullptr;
mNumDirty = 0;
// Reduce the maximum amount of dirty pages we allow to be kept on
// thread local arenas. TODO: make this more flexible.
mMaxDirty = opt_dirty_max >> 3;
mRunsAvail.Init();
- /* Initialize bins. */
+ // Initialize bins.
prev_run_size = pagesize;
- /* (2^n)-spaced tiny bins. */
+ // (2^n)-spaced tiny bins.
for (i = 0; i < ntbins; i++) {
bin = &mBins[i];
bin->runcur = nullptr;
bin->runs.Init();
bin->reg_size = (1ULL << (TINY_MIN_2POW + i));
prev_run_size = arena_bin_run_size_calc(bin, prev_run_size);
memset(&bin->stats, 0, sizeof(malloc_bin_stats_t));
}
- /* Quantum-spaced bins. */
+ // Quantum-spaced bins.
for (; i < ntbins + nqbins; i++) {
bin = &mBins[i];
bin->runcur = nullptr;
bin->runs.Init();
bin->reg_size = quantum * (i - ntbins + 1);
prev_run_size = arena_bin_run_size_calc(bin, prev_run_size);
memset(&bin->stats, 0, sizeof(malloc_bin_stats_t));
}
- /* (2^n)-spaced sub-page bins. */
+ // (2^n)-spaced sub-page bins.
for (; i < ntbins + nqbins + nsbins; i++) {
bin = &mBins[i];
bin->runcur = nullptr;
bin->runs.Init();
bin->reg_size = (small_max << (i - (ntbins + nqbins) + 1));
prev_run_size = arena_bin_run_size_calc(bin, prev_run_size);
@@ -3943,125 +3746,118 @@ arena_t::Init()
#endif
return true;
}
static inline arena_t *
arenas_fallback()
{
- /* Only reached if there is an OOM error. */
-
- /*
- * OOM here is quite inconvenient to propagate, since dealing with it
- * would require a check for failure in the fast path. Instead, punt
- * by using the first arena.
- * In practice, this is an extremely unlikely failure.
- */
+ // Only reached if there is an OOM error.
+
+ // OOM here is quite inconvenient to propagate, since dealing with it
+ // would require a check for failure in the fast path. Instead, punt
+ // by using the first arena.
+ // In practice, this is an extremely unlikely failure.
_malloc_message(_getprogname(),
": (malloc) Error initializing arena\n");
return gMainArena;
}
-/* Create a new arena and return it. */
+// Create a new arena and return it.
static arena_t*
arenas_extend()
{
arena_t* ret;
- /* Allocate enough space for trailing bins. */
+ // Allocate enough space for trailing bins.
ret = (arena_t*)base_alloc(sizeof(arena_t) +
(sizeof(arena_bin_t) * (ntbins + nqbins + nsbins - 1)));
if (!ret || !ret->Init()) {
return arenas_fallback();
}
MutexAutoLock lock(arenas_lock);
// TODO: Use random Ids.
ret->mId = narenas++;
gArenaTree.Insert(ret);
return ret;
}
-/*
- * End arena.
- */
-/******************************************************************************/
-/*
- * Begin general internal functions.
- */
+// End arena.
+// ***************************************************************************
+// Begin general internal functions.
static void *
huge_malloc(size_t size, bool zero)
{
return huge_palloc(size, chunksize, zero);
}
static void*
huge_palloc(size_t aSize, size_t aAlignment, bool aZero)
{
void* ret;
size_t csize;
size_t psize;
extent_node_t* node;
bool zeroed;
- /* Allocate one or more contiguous chunks for this request. */
-
+ // Allocate one or more contiguous chunks for this request.
csize = CHUNK_CEILING(aSize);
if (csize == 0) {
- /* size is large enough to cause size_t wrap-around. */
+ // size is large enough to cause size_t wrap-around.
return nullptr;
}
- /* Allocate an extent node with which to track the chunk. */
+ // Allocate an extent node with which to track the chunk.
node = base_node_alloc();
if (!node) {
return nullptr;
}
ret = chunk_alloc(csize, aAlignment, false, &zeroed);
if (!ret) {
base_node_dealloc(node);
return nullptr;
}
if (aZero) {
chunk_ensure_zero(ret, csize, zeroed);
}
- /* Insert node into huge. */
+ // Insert node into huge.
node->addr = ret;
psize = PAGE_CEILING(aSize);
node->size = psize;
{
MutexAutoLock lock(huge_mtx);
huge.Insert(node);
- /* Although we allocated space for csize bytes, we indicate that we've
- * allocated only psize bytes.
- *
- * If DECOMMIT is defined, this is a reasonable thing to do, since
- * we'll explicitly decommit the bytes in excess of psize.
- *
- * If DECOMMIT is not defined, then we're relying on the OS to be lazy
- * about how it allocates physical pages to mappings. If we never
- * touch the pages in excess of psize, the OS won't allocate a physical
- * page, and we won't use more than psize bytes of physical memory.
- *
- * A correct program will only touch memory in excess of how much it
- * requested if it first calls malloc_usable_size and finds out how
- * much space it has to play with. But because we set node->size =
- * psize above, malloc_usable_size will return psize, not csize, and
- * the program will (hopefully) never touch bytes in excess of psize.
- * Thus those bytes won't take up space in physical memory, and we can
- * reasonably claim we never "allocated" them in the first place. */
+ // Although we allocated space for csize bytes, we indicate that we've
+ // allocated only psize bytes.
+ //
+ // If DECOMMIT is defined, this is a reasonable thing to do, since
+ // we'll explicitly decommit the bytes in excess of psize.
+ //
+ // If DECOMMIT is not defined, then we're relying on the OS to be lazy
+ // about how it allocates physical pages to mappings. If we never
+ // touch the pages in excess of psize, the OS won't allocate a physical
+ // page, and we won't use more than psize bytes of physical memory.
+ //
+ // A correct program will only touch memory in excess of how much it
+ // requested if it first calls malloc_usable_size and finds out how
+ // much space it has to play with. But because we set node->size =
+ // psize above, malloc_usable_size will return psize, not csize, and
+ // the program will (hopefully) never touch bytes in excess of psize.
+ // Thus those bytes won't take up space in physical memory, and we can
+ // reasonably claim we never "allocated" them in the first place.
huge_allocated += psize;
huge_mapped += csize;
}
#ifdef MALLOC_DECOMMIT
if (csize - psize > 0) {
pages_decommit((void*)((uintptr_t)ret + psize), csize - psize);
}
@@ -4087,77 +3883,74 @@ huge_palloc(size_t aSize, size_t aAlignm
}
static void*
huge_ralloc(void* aPtr, size_t aSize, size_t aOldSize)
{
void* ret;
size_t copysize;
- /* Avoid moving the allocation if the size class would not change. */
-
+ // Avoid moving the allocation if the size class would not change.
if (aOldSize > arena_maxclass &&
CHUNK_CEILING(aSize) == CHUNK_CEILING(aOldSize)) {
size_t psize = PAGE_CEILING(aSize);
if (aSize < aOldSize) {
memset((void*)((uintptr_t)aPtr + aSize), kAllocPoison, aOldSize - aSize);
}
#ifdef MALLOC_DECOMMIT
if (psize < aOldSize) {
extent_node_t key;
pages_decommit((void*)((uintptr_t)aPtr + psize), aOldSize - psize);
- /* Update recorded size. */
+ // Update recorded size.
MutexAutoLock lock(huge_mtx);
key.addr = const_cast<void*>(aPtr);
extent_node_t* node = huge.Search(&key);
MOZ_ASSERT(node);
MOZ_ASSERT(node->size == aOldSize);
huge_allocated -= aOldSize - psize;
- /* No need to change huge_mapped, because we didn't (un)map anything. */
+ // No need to change huge_mapped, because we didn't (un)map anything.
node->size = psize;
} else if (psize > aOldSize) {
if (!pages_commit((void*)((uintptr_t)aPtr + aOldSize),
psize - aOldSize)) {
return nullptr;
}
}
#endif
- /* Although we don't have to commit or decommit anything if
- * DECOMMIT is not defined and the size class didn't change, we
- * do need to update the recorded size if the size increased,
- * so malloc_usable_size doesn't return a value smaller than
- * what was requested via realloc(). */
+ // Although we don't have to commit or decommit anything if
+ // DECOMMIT is not defined and the size class didn't change, we
+ // do need to update the recorded size if the size increased,
+ // so malloc_usable_size doesn't return a value smaller than
+ // what was requested via realloc().
if (psize > aOldSize) {
- /* Update recorded size. */
+ // Update recorded size.
extent_node_t key;
MutexAutoLock lock(huge_mtx);
key.addr = const_cast<void*>(aPtr);
extent_node_t* node = huge.Search(&key);
MOZ_ASSERT(node);
MOZ_ASSERT(node->size == aOldSize);
huge_allocated += psize - aOldSize;
- /* No need to change huge_mapped, because we didn't
- * (un)map anything. */
+ // No need to change huge_mapped, because we didn't
+ // (un)map anything.
node->size = psize;
}
if (opt_zero && aSize > aOldSize) {
memset((void*)((uintptr_t)aPtr + aOldSize), 0, aSize - aOldSize);
}
return aPtr;
}
- /*
- * If we get here, then aSize and aOldSize are different enough that we
- * need to use a different size class. In that case, fall back to
- * allocating new space and copying.
- */
+ // If we get here, then aSize and aOldSize are different enough that we
+ // need to use a different size class. In that case, fall back to
+ // allocating new space and copying.
ret = huge_malloc(aSize, false);
if (!ret) {
return nullptr;
}
copysize = (aSize < aOldSize) ? aSize : aOldSize;
#ifdef VM_COPY_MIN
if (copysize >= VM_COPY_MIN) {
@@ -4174,38 +3967,36 @@ huge_ralloc(void* aPtr, size_t aSize, si
static void
huge_dalloc(void* aPtr)
{
extent_node_t* node;
{
extent_node_t key;
MutexAutoLock lock(huge_mtx);
- /* Extract from tree of huge allocations. */
+ // Extract from tree of huge allocations.
key.addr = aPtr;
node = huge.Search(&key);
MOZ_ASSERT(node);
MOZ_ASSERT(node->addr == aPtr);
huge.Remove(node);
huge_allocated -= node->size;
huge_mapped -= CHUNK_CEILING(node->size);
}
- /* Unmap chunk. */
+ // Unmap chunk.
chunk_dealloc(node->addr, CHUNK_CEILING(node->size), HUGE_CHUNK);
base_node_dealloc(node);
}
-/*
- * FreeBSD's pthreads implementation calls malloc(3), so the malloc
- * implementation has to take pains to avoid infinite recursion during
- * initialization.
- */
+// FreeBSD's pthreads implementation calls malloc(3), so the malloc
+// implementation has to take pains to avoid infinite recursion during
+// initialization.
#if defined(XP_WIN)
#define malloc_init() false
#else
static inline bool
malloc_init(void)
{
if (malloc_initialized == false) {
@@ -4243,50 +4034,48 @@ malloc_init_hard(void)
const char *opts;
long result;
#ifndef XP_WIN
MutexAutoLock lock(gInitLock);
#endif
if (malloc_initialized) {
- /*
- * Another thread initialized the allocator before this one
- * acquired gInitLock.
- */
+ // Another thread initialized the allocator before this one
+ // acquired gInitLock.
return false;
}
if (!thread_arena.init()) {
return false;
}
- /* Get page size and number of CPUs */
+ // Get page size and number of CPUs
result = GetKernelPageSize();
- /* We assume that the page size is a power of 2. */
+ // We assume that the page size is a power of 2.
MOZ_ASSERT(((result - 1) & result) == 0);
#ifdef MALLOC_STATIC_PAGESIZE
if (pagesize % (size_t) result) {
_malloc_message(_getprogname(),
"Compile-time page size does not divide the runtime one.\n");
MOZ_CRASH();
}
#else
pagesize = (size_t) result;
pagesize_mask = (size_t) result - 1;
pagesize_2pow = ffs((int)result) - 1;
#endif
- /* Get runtime configuration. */
+ // Get runtime configuration.
if ((opts = getenv("MALLOC_OPTIONS"))) {
for (i = 0; opts[i] != '\0'; i++) {
unsigned j, nreps;
bool nseen;
- /* Parse repetition count, if any. */
+ // Parse repetition count, if any.
for (nreps = 0, nseen = false;; i++, nseen = true) {
switch (opts[i]) {
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
case '8': case '9':
nreps *= 10;
nreps += opts[i] - '0';
break;
@@ -4338,99 +4127,91 @@ MALLOC_OUT:
"'\n");
}
}
}
}
}
#ifndef MALLOC_STATIC_PAGESIZE
- /* Set bin-related variables. */
+ // Set bin-related variables.
bin_maxclass = (pagesize >> 1);
nsbins = pagesize_2pow - SMALL_MAX_2POW_DEFAULT - 1;
chunk_npages = (chunksize >> pagesize_2pow);
arena_chunk_header_npages = calculate_arena_header_pages();
arena_maxclass = calculate_arena_maxclass();
#endif
gRecycledSize = 0;
- /* Various sanity checks that regard configuration. */
+ // Various sanity checks that regard configuration.
MOZ_ASSERT(quantum >= sizeof(void *));
MOZ_ASSERT(quantum <= pagesize);
MOZ_ASSERT(chunksize >= pagesize);
MOZ_ASSERT(quantum * 4 <= chunksize);
- /* Initialize chunks data. */
+ // Initialize chunks data.
chunks_mtx.Init();
gChunksBySize.Init();
gChunksByAddress.Init();
- /* Initialize huge allocation data. */
+ // Initialize huge allocation data.
huge_mtx.Init();
huge.Init();
huge_allocated = 0;
huge_mapped = 0;
- /* Initialize base allocation data structures. */
+ // Initialize base allocation data structures.
base_mapped = 0;
base_committed = 0;
base_nodes = nullptr;
base_mtx.Init();
arenas_lock.Init();
- /*
- * Initialize one arena here.
- */
+ // Initialize one arena here.
gArenaTree.Init();
arenas_extend();
gMainArena = gArenaTree.First();
if (!gMainArena) {
return true;
}
- /* arena_t::Init() sets this to a lower value for thread local arenas;
- * reset to the default value for the main arena. */
+ // arena_t::Init() sets this to a lower value for thread local arenas;
+ // reset to the default value for the main arena.
gMainArena->mMaxDirty = opt_dirty_max;
- /*
- * Assign the initial arena to the initial thread.
- */
+ // Assign the initial arena to the initial thread.
thread_arena.set(gMainArena);
if (!gChunkRTree.Init()) {
return true;
}
malloc_initialized = true;
// Dummy call so that the function is not removed by dead-code elimination
Debug::jemalloc_ptr_info(nullptr);
#if !defined(XP_WIN) && !defined(XP_DARWIN)
- /* Prevent potential deadlock on malloc locks after fork. */
+ // Prevent potential deadlock on malloc locks after fork.
pthread_atfork(_malloc_prefork, _malloc_postfork_parent, _malloc_postfork_child);
#endif
return false;
}
-/*
- * End general internal functions.
- */
-/******************************************************************************/
-/*
- * Begin malloc(3)-compatible functions.
- */
-
-/* The BaseAllocator class is a helper class that implements the base allocator
- * functions (malloc, calloc, realloc, free, memalign) for a given arena,
- * or an appropriately chosen arena (per choose_arena()) when none is given. */
+// End general internal functions.
+// ***************************************************************************
+// Begin malloc(3)-compatible functions.
+
+// The BaseAllocator class is a helper class that implements the base allocator
+// functions (malloc, calloc, realloc, free, memalign) for a given arena,
+// or an appropriately chosen arena (per choose_arena()) when none is given.
struct BaseAllocator {
#define MALLOC_DECL(name, return_type, ...) \
inline return_type name(__VA_ARGS__);
#define MALLOC_FUNCS MALLOC_FUNCS_MALLOC_BASE
#include "malloc_decls.h"
explicit BaseAllocator(arena_t* aArena) : mArena(aArena) { }
@@ -4502,24 +4283,23 @@ BaseAllocator::calloc(size_t aNum, size_
if (malloc_init()) {
ret = nullptr;
goto RETURN;
}
size_t num_size = aNum * aSize;
if (num_size == 0) {
num_size = 1;
- /*
- * Try to avoid division here. We know that it isn't possible to
- * overflow during multiplication if neither operand uses any of the
- * most significant half of the bits in a size_t.
- */
+
+ // Try to avoid division here. We know that it isn't possible to
+ // overflow during multiplication if neither operand uses any of the
+ // most significant half of the bits in a size_t.
} else if (((aNum | aSize) & (SIZE_T_MAX << (sizeof(size_t) << 2)))
&& (num_size / aSize != aNum)) {
- /* size_t overflow. */
+ // size_t overflow.
ret = nullptr;
goto RETURN;
}
ret = imalloc(num_size, /* zero = */ true, mArena);
RETURN:
if (!ret) {
@@ -4578,23 +4358,22 @@ BaseAllocator::free(void* aPtr)
template<void* (*memalign)(size_t, size_t)>
struct AlignedAllocator
{
static inline int
posix_memalign(void** aMemPtr, size_t aAlignment, size_t aSize)
{
void* result;
- /* alignment must be a power of two and a multiple of sizeof(void*) */
+ // alignment must be a power of two and a multiple of sizeof(void*)
if (((aAlignment - 1) & aAlignment) != 0 || aAlignment < sizeof(void*)) {
return EINVAL;
}
- /* The 0-->1 size promotion is done in the memalign() call below */
-
+ // The 0-->1 size promotion is done in the memalign() call below
result = memalign(aAlignment, aSize);
if (!result) {
return ENOMEM;
}
*aMemPtr = result;
return 0;
@@ -4629,59 +4408,50 @@ MozJemalloc::aligned_alloc(size_t aAlign
}
template<> inline void*
MozJemalloc::valloc(size_t aSize)
{
return AlignedAllocator<memalign>::valloc(aSize);
}
-/*
- * End malloc(3)-compatible functions.
- */
-/******************************************************************************/
-/*
- * Begin non-standard functions.
- */
-
-/* This was added by Mozilla for use by SQLite. */
+// End malloc(3)-compatible functions.
+// ***************************************************************************
+// Begin non-standard functions.
+
+// This was added by Mozilla for use by SQLite.
template<> inline size_t
MozJemalloc::malloc_good_size(size_t aSize)
{
- /*
- * This duplicates the logic in imalloc(), arena_malloc() and
- * arena_t::MallocSmall().
- */
+ // This duplicates the logic in imalloc(), arena_malloc() and
+ // arena_t::MallocSmall().
if (aSize < small_min) {
- /* Small (tiny). */
+ // Small (tiny).
aSize = pow2_ceil(aSize);
- /*
- * We omit the #ifdefs from arena_t::MallocSmall() --
- * it can be inaccurate with its size in some cases, but this
- * function must be accurate.
- */
+
+ // We omit the #ifdefs from arena_t::MallocSmall() --
+ // it can be inaccurate with its size in some cases, but this
+ // function must be accurate.
if (aSize < (1U << TINY_MIN_2POW)) {
aSize = (1U << TINY_MIN_2POW);
}
} else if (aSize <= small_max) {
- /* Small (quantum-spaced). */
+ // Small (quantum-spaced).
aSize = QUANTUM_CEILING(aSize);
} else if (aSize <= bin_maxclass) {
- /* Small (sub-page). */
+ // Small (sub-page).
aSize = pow2_ceil(aSize);
} else if (aSize <= arena_maxclass) {
- /* Large. */
+ // Large.
aSize = PAGE_CEILING(aSize);
} else {
- /*
- * Huge. We use PAGE_CEILING to get psize, instead of using
- * CHUNK_CEILING to get csize. This ensures that this
- * malloc_usable_size(malloc(n)) always matches
- * malloc_good_size(n).
- */
+ // Huge. We use PAGE_CEILING to get psize, instead of using
+ // CHUNK_CEILING to get csize. This ensures that this
+ // malloc_usable_size(malloc(n)) always matches
+ // malloc_good_size(n).
aSize = PAGE_CEILING(aSize);
}
return aSize;
}
template<> inline size_t
MozJemalloc::malloc_usable_size(usable_ptr_t aPtr)
@@ -4691,59 +4461,55 @@ MozJemalloc::malloc_usable_size(usable_p
template<> inline void
MozJemalloc::jemalloc_stats(jemalloc_stats_t* aStats)
{
size_t non_arena_mapped, chunk_header_size;
MOZ_ASSERT(aStats);
- /*
- * Gather runtime settings.
- */
+ // Gather runtime settings.
aStats->opt_junk = opt_junk;
aStats->opt_zero = opt_zero;
aStats->narenas = narenas;
aStats->quantum = quantum;
aStats->small_max = small_max;
aStats->large_max = arena_maxclass;
aStats->chunksize = chunksize;
aStats->page_size = pagesize;
aStats->dirty_max = opt_dirty_max;
- /*
- * Gather current memory usage statistics.
- */
+ // Gather current memory usage statistics.
aStats->mapped = 0;
aStats->allocated = 0;
aStats->waste = 0;
aStats->page_cache = 0;
aStats->bookkeeping = 0;
aStats->bin_unused = 0;
non_arena_mapped = 0;
- /* Get huge mapped/allocated. */
+ // Get huge mapped/allocated.
{
MutexAutoLock lock(huge_mtx);
non_arena_mapped += huge_mapped;
aStats->allocated += huge_allocated;
MOZ_ASSERT(huge_mapped >= huge_allocated);
}
- /* Get base mapped/allocated. */
+ // Get base mapped/allocated.
{
MutexAutoLock lock(base_mtx);
non_arena_mapped += base_mapped;
aStats->bookkeeping += base_committed;
MOZ_ASSERT(base_mapped >= base_committed);
}
arenas_lock.Lock();
- /* Iterate over arenas. */
+ // Iterate over arenas.
for (auto arena : gArenaTree.iter()) {
size_t arena_mapped, arena_allocated, arena_committed, arena_dirty, j,
arena_unused, arena_headers;
arena_run_t* run;
if (!arena) {
continue;
}
@@ -4751,17 +4517,17 @@ MozJemalloc::jemalloc_stats(jemalloc_sta
arena_headers = 0;
arena_unused = 0;
{
MutexAutoLock lock(arena->mLock);
arena_mapped = arena->mStats.mapped;
- /* "committed" counts dirty and allocated memory. */
+ // "committed" counts dirty and allocated memory.
arena_committed = arena->mStats.committed << pagesize_2pow;
arena_allocated = arena->mStats.allocated_small +
arena->mStats.allocated_large;
arena_dirty = arena->mNumDirty << pagesize_2pow;
for (j = 0; j < ntbins + nqbins + nsbins; j++) {
@@ -4780,74 +4546,74 @@ MozJemalloc::jemalloc_stats(jemalloc_sta
arena_unused += bin_unused;
arena_headers += bin->stats.curruns * bin->reg0_offset;
}
}
MOZ_ASSERT(arena_mapped >= arena_committed);
MOZ_ASSERT(arena_committed >= arena_allocated + arena_dirty);
- /* "waste" is committed memory that is neither dirty nor
- * allocated. */
+ // "waste" is committed memory that is neither dirty nor
+ // allocated.
aStats->mapped += arena_mapped;
aStats->allocated += arena_allocated;
aStats->page_cache += arena_dirty;
aStats->waste += arena_committed -
arena_allocated - arena_dirty - arena_unused - arena_headers;
aStats->bin_unused += arena_unused;
aStats->bookkeeping += arena_headers;
}
arenas_lock.Unlock();
- /* Account for arena chunk headers in bookkeeping rather than waste. */
+ // Account for arena chunk headers in bookkeeping rather than waste.
chunk_header_size =
((aStats->mapped / aStats->chunksize) * arena_chunk_header_npages) <<
pagesize_2pow;
aStats->mapped += non_arena_mapped;
aStats->bookkeeping += chunk_header_size;
aStats->waste -= chunk_header_size;
MOZ_ASSERT(aStats->mapped >= aStats->allocated + aStats->waste +
aStats->page_cache + aStats->bookkeeping);
}
#ifdef MALLOC_DOUBLE_PURGE
-/* Explicitly remove all of this chunk's MADV_FREE'd pages from memory. */
+// Explicitly remove all of this chunk's MADV_FREE'd pages from memory.
static void
hard_purge_chunk(arena_chunk_t* aChunk)
{
- /* See similar logic in arena_t::Purge(). */
+ // See similar logic in arena_t::Purge().
for (size_t i = arena_chunk_header_npages; i < chunk_npages; i++) {
- /* Find all adjacent pages with CHUNK_MAP_MADVISED set. */
+ // Find all adjacent pages with CHUNK_MAP_MADVISED set.
size_t npages;
for (npages = 0; aChunk->map[i + npages].bits & CHUNK_MAP_MADVISED &&
i + npages < chunk_npages;
npages++) {
- /* Turn off the chunk's MADV_FREED bit and turn on its
- * DECOMMITTED bit. */
+ // Turn off the chunk's MADV_FREED bit and turn on its
+ // DECOMMITTED bit.
MOZ_DIAGNOSTIC_ASSERT(
!(aChunk->map[i + npages].bits & CHUNK_MAP_DECOMMITTED));
aChunk->map[i + npages].bits ^= CHUNK_MAP_MADVISED_OR_DECOMMITTED;
}
- /* We could use mincore to find out which pages are actually
- * present, but it's not clear that's better. */
+ // We could use mincore to find out which pages are actually
+ // present, but it's not clear that's better.
if (npages > 0) {
pages_decommit(((char*)aChunk) + (i << pagesize_2pow),
npages << pagesize_2pow);
mozilla::Unused << pages_commit(((char*)aChunk) + (i << pagesize_2pow),
npages << pagesize_2pow);
}
i += npages;
}
}
-/* Explicitly remove all of this arena's MADV_FREE'd pages from memory. */
+// Explicitly remove all of this arena's MADV_FREE'd pages from memory.
void
arena_t::HardPurge()
{
MutexAutoLock lock(mLock);
while (!mChunksMAdvised.isEmpty()) {
arena_chunk_t* chunk = mChunksMAdvised.popFront();
hard_purge_chunk(chunk);
@@ -4858,25 +4624,25 @@ template<> inline void
MozJemalloc::jemalloc_purge_freed_pages()
{
MutexAutoLock lock(arenas_lock);
for (auto arena : gArenaTree.iter()) {
arena->HardPurge();
}
}
-#else /* !defined MALLOC_DOUBLE_PURGE */
+#else // !defined MALLOC_DOUBLE_PURGE
template<> inline void
MozJemalloc::jemalloc_purge_freed_pages()
{
- /* Do nothing. */
+ // Do nothing.
}
-#endif /* defined MALLOC_DOUBLE_PURGE */
+#endif // defined MALLOC_DOUBLE_PURGE
template<> inline void
MozJemalloc::jemalloc_free_dirty_pages(void)
{
MutexAutoLock lock(arenas_lock);
for (auto arena : gArenaTree.iter()) {
MutexAutoLock arena_lock(arena->mLock);
@@ -4932,35 +4698,29 @@ MozJemalloc::moz_dispose_arena(arena_id_
{ \
return DummyArenaAllocator<MozJemalloc>::name(ARGS_HELPER(ARGS, ##__VA_ARGS__)); \
}
#define MALLOC_FUNCS MALLOC_FUNCS_ARENA
#include "malloc_decls.h"
#endif
-/*
- * End non-standard functions.
- */
-/******************************************************************************/
-/*
- * Begin library-private functions, used by threading libraries for protection
- * of malloc during fork(). These functions are only called if the program is
- * running in threaded mode, so there is no need to check whether the program
- * is threaded here.
- */
-
+// End non-standard functions.
+// ***************************************************************************
+// Begin library-private functions, used by threading libraries for protection
+// of malloc during fork(). These functions are only called if the program is
+// running in threaded mode, so there is no need to check whether the program
+// is threaded here.
#ifndef XP_DARWIN
static
#endif
void
_malloc_prefork(void)
{
- /* Acquire all mutexes in a safe order. */
-
+ // Acquire all mutexes in a safe order.
arenas_lock.Lock();
for (auto arena : gArenaTree.iter()) {
arena->mLock.Lock();
}
base_mtx.Lock();
@@ -4968,62 +4728,55 @@ void
}
#ifndef XP_DARWIN
static
#endif
void
_malloc_postfork_parent(void)
{
- /* Release all mutexes, now that fork() has completed. */
-
+ // Release all mutexes, now that fork() has completed.
huge_mtx.Unlock();
base_mtx.Unlock();
for (auto arena : gArenaTree.iter()) {
arena->mLock.Unlock();
}
arenas_lock.Unlock();
}
#ifndef XP_DARWIN
static
#endif
void
_malloc_postfork_child(void)
{
- /* Reinitialize all mutexes, now that fork() has completed. */
-
+ // Reinitialize all mutexes, now that fork() has completed.
huge_mtx.Init();
base_mtx.Init();
for (auto arena : gArenaTree.iter()) {
arena->mLock.Init();
}
arenas_lock.Init();
}
-/*
- * End library-private functions.
- */
-/******************************************************************************/
+// End library-private functions.
+// ***************************************************************************
#ifdef MOZ_REPLACE_MALLOC
-
-/*
- * Windows doesn't come with weak imports as they are possible with
- * LD_PRELOAD or DYLD_INSERT_LIBRARIES on Linux/OSX. On this platform,
- * the replacement functions are defined as variable pointers to the
- * function resolved with GetProcAddress() instead of weak definitions
- * of functions. On Android, the same needs to happen as well, because
- * the Android linker doesn't handle weak linking with non LD_PRELOADed
- * libraries, but LD_PRELOADing is not very convenient on Android, with
- * the zygote.
- */
+// Windows doesn't come with weak imports as they are possible with
+// LD_PRELOAD or DYLD_INSERT_LIBRARIES on Linux/OSX. On this platform,
+// the replacement functions are defined as variable pointers to the
+// function resolved with GetProcAddress() instead of weak definitions
+// of functions. On Android, the same needs to happen as well, because
+// the Android linker doesn't handle weak linking with non LD_PRELOADed
+// libraries, but LD_PRELOADing is not very convenient on Android, with
+// the zygote.
#ifdef XP_DARWIN
# define MOZ_REPLACE_WEAK __attribute__((weak_import))
#elif defined(XP_WIN) || defined(MOZ_WIDGET_ANDROID)
# define MOZ_NO_REPLACE_FUNC_DECL
#elif defined(__GNUC__)
# define MOZ_REPLACE_WEAK __attribute__((weak))
#endif
@@ -5093,21 +4846,18 @@ replace_malloc_handle()
# define REPLACE_MALLOC_GET_FUNC(handle, name) \
replace_##name
#endif
static void replace_malloc_init_funcs();
-/*
- * Below is the malloc implementation overriding jemalloc and calling the
- * replacement functions if they exist.
- */
-
+// Below is the malloc implementation overriding jemalloc and calling the
+// replacement functions if they exist.
static int replace_malloc_initialized = 0;
static void
init()
{
replace_malloc_init_funcs();
// Set this *before* calling replace_init, otherwise if replace_init calls
// malloc() we'll get an infinite loop.
replace_malloc_initialized = 1;
@@ -5134,23 +4884,21 @@ get_bridge(void)
init();
}
if (MOZ_LIKELY(!replace_get_bridge)) {
return nullptr;
}
return replace_get_bridge();
}
-/*
- * posix_memalign, aligned_alloc, memalign and valloc all implement some kind
- * of aligned memory allocation. For convenience, a replace-malloc library can
- * skip defining replace_posix_memalign, replace_aligned_alloc and
- * replace_valloc, and default implementations will be automatically derived
- * from replace_memalign.
- */
+// posix_memalign, aligned_alloc, memalign and valloc all implement some kind
+// of aligned memory allocation. For convenience, a replace-malloc library can
+// skip defining replace_posix_memalign, replace_aligned_alloc and
+// replace_valloc, and default implementations will be automatically derived
+// from replace_memalign.
static void
replace_malloc_init_funcs()
{
replace_malloc_handle_t handle = replace_malloc_handle();
if (handle) {
#ifdef MOZ_NO_REPLACE_FUNC_DECL
# define MALLOC_DECL(name, ...) \
replace_##name = REPLACE_MALLOC_GET_FUNC(handle, name);
@@ -5182,19 +4930,19 @@ replace_malloc_init_funcs()
#define MALLOC_DECL(name, ...) \
if (!replace_malloc_table.name) { \
replace_malloc_table.name = MozJemalloc::name; \
}
#include "malloc_decls.h"
}
-#endif /* MOZ_REPLACE_MALLOC */
-/******************************************************************************/
-/* Definition of all the _impl functions */
+#endif // MOZ_REPLACE_MALLOC
+// ***************************************************************************
+// Definition of all the _impl functions
#define GENERIC_MALLOC_DECL2(name, name_impl, return_type, ...) \
return_type name_impl(ARGS_HELPER(TYPED_ARGS, ##__VA_ARGS__)) \
{ \
return DefaultMalloc::name(ARGS_HELPER(ARGS, ##__VA_ARGS__)); \
}
#define GENERIC_MALLOC_DECL(name, return_type, ...) \
@@ -5206,107 +4954,97 @@ replace_malloc_init_funcs()
#undef GENERIC_MALLOC_DECL
#define GENERIC_MALLOC_DECL(name, return_type, ...) \
GENERIC_MALLOC_DECL2(name, name, return_type, ##__VA_ARGS__)
#define MALLOC_DECL(...) MOZ_JEMALLOC_API MACRO_CALL(GENERIC_MALLOC_DECL, (__VA_ARGS__))
#define MALLOC_FUNCS (MALLOC_FUNCS_JEMALLOC | MALLOC_FUNCS_ARENA)
#include "malloc_decls.h"
-/******************************************************************************/
+// ***************************************************************************
#ifdef HAVE_DLOPEN
# include <dlfcn.h>
#endif
#if defined(__GLIBC__) && !defined(__UCLIBC__)
-/*
- * glibc provides the RTLD_DEEPBIND flag for dlopen which can make it possible
- * to inconsistently reference libc's malloc(3)-compatible functions
- * (bug 493541).
- *
- * These definitions interpose hooks in glibc. The functions are actually
- * passed an extra argument for the caller return address, which will be
- * ignored.
- */
+// glibc provides the RTLD_DEEPBIND flag for dlopen which can make it possible
+// to inconsistently reference libc's malloc(3)-compatible functions
+// (bug 493541).
+//
+// These definitions interpose hooks in glibc. The functions are actually
+// passed an extra argument for the caller return address, which will be
+// ignored.
+
extern "C" {
MOZ_EXPORT void (*__free_hook)(void*) = free_impl;
MOZ_EXPORT void* (*__malloc_hook)(size_t) = malloc_impl;
MOZ_EXPORT void* (*__realloc_hook)(void*, size_t) = realloc_impl;
MOZ_EXPORT void* (*__memalign_hook)(size_t, size_t) = memalign_impl;
}
#elif defined(RTLD_DEEPBIND)
-/*
- * XXX On systems that support RTLD_GROUP or DF_1_GROUP, do their
- * implementations permit similar inconsistencies? Should STV_SINGLETON
- * visibility be used for interposition where available?
- */
+// XXX On systems that support RTLD_GROUP or DF_1_GROUP, do their
+// implementations permit similar inconsistencies? Should STV_SINGLETON
+// visibility be used for interposition where available?
# error "Interposing malloc is unsafe on this system without libc malloc hooks."
#endif
#ifdef XP_WIN
void*
_recalloc(void* aPtr, size_t aCount, size_t aSize)
{
size_t oldsize = aPtr ? isalloc(aPtr) : 0;
size_t newsize = aCount * aSize;
- /*
- * In order for all trailing bytes to be zeroed, the caller needs to
- * use calloc(), followed by recalloc(). However, the current calloc()
- * implementation only zeros the bytes requested, so if recalloc() is
- * to work 100% correctly, calloc() will need to change to zero
- * trailing bytes.
- */
-
+ // In order for all trailing bytes to be zeroed, the caller needs to
+ // use calloc(), followed by recalloc(). However, the current calloc()
+ // implementation only zeros the bytes requested, so if recalloc() is
+ // to work 100% correctly, calloc() will need to change to zero
+ // trailing bytes.
aPtr = DefaultMalloc::realloc(aPtr, newsize);
if (aPtr && oldsize < newsize) {
memset((void*)((uintptr_t)aPtr + oldsize), 0, newsize - oldsize);
}
return aPtr;
}
-/*
- * This impl of _expand doesn't ever actually expand or shrink blocks: it
- * simply replies that you may continue using a shrunk block.
- */
+// This impl of _expand doesn't ever actually expand or shrink blocks: it
+// simply replies that you may continue using a shrunk block.
void*
_expand(void* aPtr, size_t newsize)
{
if (isalloc(aPtr) >= newsize) {
return aPtr;
}
return nullptr;
}
size_t
_msize(void* aPtr)
{
return DefaultMalloc::malloc_usable_size(aPtr);
}
-/*
- * In the new style jemalloc integration jemalloc is built as a separate
- * shared library. Since we're no longer hooking into the CRT binary,
- * we need to initialize the heap at the first opportunity we get.
- * DLL_PROCESS_ATTACH in DllMain is that opportunity.
- */
+// In the new style jemalloc integration jemalloc is built as a separate
+// shared library. Since we're no longer hooking into the CRT binary,
+// we need to initialize the heap at the first opportunity we get.
+// DLL_PROCESS_ATTACH in DllMain is that opportunity.
BOOL APIENTRY DllMain(HINSTANCE hModule,
DWORD reason,
LPVOID lpReserved)
{
switch (reason) {
case DLL_PROCESS_ATTACH:
- /* Don't force the system to page DllMain back in every time
- * we create/destroy a thread */
+ // Don't force the system to page DllMain back in every time
+ // we create/destroy a thread
DisableThreadLibraryCalls(hModule);
- /* Initialize the heap */
+ // Initialize the heap
malloc_init_hard();
break;
case DLL_PROCESS_DETACH:
break;
}
