--- a/browser/components/extensions/ext-tabs.js
+++ b/browser/components/extensions/ext-tabs.js
@@ -3,16 +3,18 @@
"use strict";
XPCOMUtils.defineLazyServiceGetter(this, "aboutNewTabService",
"@mozilla.org/browser/aboutnewtab-service;1",
"nsIAboutNewTabService");
XPCOMUtils.defineLazyModuleGetter(this, "MatchPattern",
"resource://gre/modules/MatchPattern.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "MessageChannel",
+ "resource://gre/modules/MessageChannel.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "Services",
"resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/ExtensionUtils.jsm");
var {
EventManager,
@@ -443,24 +445,20 @@ extensions.registerSchemaAPI("tabs", nul
_execute: function(tabId, details, kind, callback) {
let tab = tabId !== null ? TabManager.getTab(tabId) : TabManager.activeTab;
let mm = tab.linkedBrowser.messageManager;
let options = {
js: [],
css: [],
+ };
- // We need to send the inner window ID to make sure we only
- // execute the script if the window is currently navigated to
- // the document that we expect.
- //
- // TODO: When we add support for callbacks, non-matching
- // window IDs and insufficient permissions need to result in a
- // callback with |lastError| set.
+ let recipient = {
+ extensionId: extension.id,
innerWindowID: tab.linkedBrowser.innerWindowID,
};
if (TabManager.for(extension).hasActiveTabPermission(tab)) {
// If we have the "activeTab" permission for this tab, ignore
// the host whitelist.
options.matchesHost = ["<all_urls>"];
} else {
@@ -482,18 +480,18 @@ extensions.registerSchemaAPI("tabs", nul
options.all_frames = details.allFrames;
}
if (details.matchAboutBlank) {
options.match_about_blank = details.matchAboutBlank;
}
if (details.runAt !== null) {
options.run_at = details.runAt;
}
- mm.sendAsyncMessage("Extension:Execute",
- {extensionId: extension.id, options});
+
+ MessageChannel.sendMessage(mm, "Extension:Execute", { options }, recipient);
// TODO: Call the callback with the result (which is what???).
},
executeScript: function(tabId, details, callback) {
self.tabs._execute(tabId, details, "js", callback);
},
--- a/toolkit/components/extensions/Extension.jsm
+++ b/toolkit/components/extensions/Extension.jsm
@@ -45,16 +45,18 @@ XPCOMUtils.defineLazyModuleGetter(this,
XPCOMUtils.defineLazyModuleGetter(this, "Preferences",
"resource://gre/modules/Preferences.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "Schemas",
"resource://gre/modules/Schemas.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "Task",
"resource://gre/modules/Task.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "AppConstants",
"resource://gre/modules/AppConstants.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "MessageChannel",
+ "resource://gre/modules/MessageChannel.jsm");
Cu.import("resource://gre/modules/ExtensionManagement.jsm");
// Register built-in parts of the API. Other parts may be registered
// in browser/, mobile/, or b2g/.
ExtensionManagement.registerScript("chrome://extensions/content/ext-alarms.js");
ExtensionManagement.registerScript("chrome://extensions/content/ext-backgroundPage.js");
ExtensionManagement.registerScript("chrome://extensions/content/ext-cookies.js");
@@ -1071,16 +1073,18 @@ Extension.prototype = extend(Object.crea
for (let obj of this.onShutdown) {
obj.close();
}
Management.emit("shutdown", this);
Services.ppmm.broadcastAsyncMessage("Extension:Shutdown", {id: this.id});
+ MessageChannel.abortResponses({ extensionId: this.id });
+
ExtensionManagement.shutdownExtension(this.uuid);
// Clean up a generated file.
this.cleanupGeneratedFile();
},
observe(subject, topic, data) {
if (topic == "xpcom-shutdown") {
--- a/toolkit/components/extensions/ExtensionContent.jsm
+++ b/toolkit/components/extensions/ExtensionContent.jsm
@@ -24,16 +24,18 @@ Cu.import("resource://gre/modules/Servic
Cu.import("resource://gre/modules/AppConstants.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "ExtensionManagement",
"resource://gre/modules/ExtensionManagement.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "MatchPattern",
"resource://gre/modules/MatchPattern.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "PrivateBrowsingUtils",
"resource://gre/modules/PrivateBrowsingUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "MessageChannel",
+ "resource://gre/modules/MessageChannel.jsm");
Cu.import("resource://gre/modules/ExtensionUtils.jsm");
var {
runSafeSyncWithoutClone,
LocaleData,
MessageBroker,
Messenger,
injectAPI,
@@ -132,26 +134,16 @@ Script.prototype = {
if (this.exclude_matches_.matches(uri)) {
return false;
}
if (!this.options.all_frames && window.top != window) {
return false;
}
- if ("innerWindowID" in this.options) {
- let innerWindowID = window.QueryInterface(Ci.nsIInterfaceRequestor)
- .getInterface(Ci.nsIDOMWindowUtils)
- .currentInnerWindowID;
-
- if (innerWindowID !== this.options.innerWindowID) {
- return false;
- }
- }
-
// TODO: match_about_blank.
return true;
},
tryInject(extension, window, sandbox, shouldRun) {
if (!this.matches(window)) {
return;
@@ -399,16 +391,18 @@ var DocumentManager = {
this.trigger("document_start", window);
/* eslint-disable mozilla/balanced-listeners */
window.addEventListener("DOMContentLoaded", this, true);
window.addEventListener("load", this, true);
/* eslint-enable mozilla/balanced-listeners */
} else if (topic == "inner-window-destroyed") {
let windowId = subject.QueryInterface(Ci.nsISupportsPRUint64).data;
+ MessageChannel.abortResponses({ innerWindowID: windowId });
+
// Close any existent content-script context for the destroyed window.
if (this.contentScriptWindows.has(windowId)) {
let extensions = this.contentScriptWindows.get(windowId);
for (let [, context] of extensions) {
context.close();
}
this.contentScriptWindows.delete(windowId);
@@ -441,17 +435,17 @@ var DocumentManager = {
this.trigger("document_idle", window);
}
},
executeScript(global, extensionId, script) {
let window = global.content;
let context = this.getContentScriptContext(extensionId, window);
if (!context) {
- return;
+ throw new Error("Unexpected add-on ID");
}
// TODO: Somehow make sure we have the right permissions for this origin!
// FIXME: Script should be executed only if current state has
// already reached its run_at state, or we have to keep it around
// somewhere to execute later.
context.execute(script, scheduled => true);
@@ -530,16 +524,18 @@ var DocumentManager = {
// Clean up iframe extension page contexts on extension shutdown.
for (let [winId, context] of this.extensionPageWindows) {
if (context.extensionId == extensionId) {
context.close();
this.extensionPageWindows.delete(winId);
}
}
+ MessageChannel.abortResponses({ extensionId });
+
this.extensionCount--;
if (this.extensionCount == 0) {
this.uninit();
}
},
trigger(when, window) {
let state = this.getWindowState(window);
@@ -640,50 +636,66 @@ ExtensionManager = {
flushJarCache(file);
Services.cpmm.sendAsyncMessage("Extension:FlushJarCacheComplete");
break;
}
}
},
};
+class ExtensionGlobal {
+ constructor(global) {
+ this.global = global;
+
+ MessageChannel.addListener(global, "Extension:Execute", this);
+
+ this.broker = new MessageBroker([global]);
+
+ this.windowId = global.content
+ .QueryInterface(Ci.nsIInterfaceRequestor)
+ .getInterface(Ci.nsIDOMWindowUtils)
+ .outerWindowID;
+
+ global.sendAsyncMessage("Extension:TopWindowID", { windowId: this.windowId });
+ }
+
+ uninit() {
+ this.global.sendAsyncMessage("Extension:RemoveTopWindowID", { windowId: this.windowId });
+ }
+
+ get messageFilter() {
+ return {
+ innerWindowID: this.global.content
+ .QueryInterface(Ci.nsIInterfaceRequestor)
+ .getInterface(Ci.nsIDOMWindowUtils)
+ .currentInnerWindowID,
+ };
+ }
+
+ receiveMessage({ target, messageName, recipient, data }) {
+ switch (messageName) {
+ case "Extension:Execute":
+ let script = new Script(data.options);
+ let { extensionId } = recipient;
+ DocumentManager.executeScript(target, extensionId, script);
+ break;
+ }
+ }
+}
+
this.ExtensionContent = {
globals: new Map(),
init(global) {
- let broker = new MessageBroker([global]);
- this.globals.set(global, broker);
-
- global.addMessageListener("Extension:Execute", this);
-
- let windowId = global.content
- .QueryInterface(Ci.nsIInterfaceRequestor)
- .getInterface(Ci.nsIDOMWindowUtils)
- .outerWindowID;
- global.sendAsyncMessage("Extension:TopWindowID", {windowId});
+ this.globals.set(global, new ExtensionGlobal(global));
},
uninit(global) {
+ this.globals.get(global).uninit();
this.globals.delete(global);
-
- let windowId = global.content
- .QueryInterface(Ci.nsIInterfaceRequestor)
- .getInterface(Ci.nsIDOMWindowUtils)
- .outerWindowID;
- global.sendAsyncMessage("Extension:RemoveTopWindowID", {windowId});
},
getBroker(messageManager) {
- return this.globals.get(messageManager);
- },
-
- receiveMessage({target, name, data}) {
- switch (name) {
- case "Extension:Execute":
- let script = new Script(data.options);
- let {extensionId} = data;
- DocumentManager.executeScript(target, extensionId, script);
- break;
- }
+ return this.globals.get(messageManager).broker;
},
};
ExtensionManager.init();
new file mode 100644
--- /dev/null
+++ b/toolkit/components/extensions/MessageChannel.jsm
@@ -0,0 +1,610 @@
+/* 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/. */
+
+"use strict";
+
+/**
+ * This module provides wrappers around standard message managers to
+ * simplify bidirectional communication. It currently allows a caller to
+ * send a message to a single listener, and receive a reply. If there
+ * are no matching listeners, or the message manager disconnects before
+ * a reply is received, the caller is returned an error.
+ *
+ * Since each message may have only one recipient, the listener end may
+ * specify filters for the messages it wishes to receive, and the sender
+ * end likewise may specify recipient tags to match the filters.
+ *
+ * The message handler on the listener side may return its response
+ * value directly, or may return a promise, the resolution or rejection
+ * of which will be returned instead. The sender end likewise receives a
+ * promise which resolves or rejects to the listener's response.
+ *
+ *
+ * A basic setup works something like this:
+ *
+ * A content script adds a message listener to its global
+ * nsIContentFrameMessageManager, with an appropriate set of filters:
+ *
+ * {
+ * init(messageManager, window, extensionID) {
+ * this.window = window;
+ *
+ * MessageChannel.addListener(
+ * messageManager, "ContentScript:TouchContent",
+ * this);
+ *
+ * this.messageFilter = {
+ * innerWindowID: getInnerWindowID(window),
+ * extensionID: extensionID,
+ * };
+ * },
+ *
+ * receiveMessage({ target, messageName, sender, recipient, data }) {
+ * if (messageName == "ContentScript:TouchContent") {
+ * return new Promise(resolve => {
+ * this.touchWindow(data.touchWith, result => {
+ * resolve({ touchResult: result });
+ * });
+ * });
+ * }
+ * },
+ * };
+ *
+ * A script in the parent process sends a message to the content process
+ * via a tab message manager, including recipient tags to match its
+ * filter, and an optional sender tag to identify itself:
+ *
+ * let data = { touchWith: "pencil" };
+ * let sender = { extensionID, contextID };
+ * let recipient = { innerWindowID: tab.linkedBrowser.innerWindowID, extensionID };
+ *
+ * MessageChannel.sendMessage(
+ * tab.linkedBrowser.messageManager, "ContentScript:TouchContent",
+ * data, recipient, sender
+ * ).then(result => {
+ * alert(result.touchResult);
+ * });
+ *
+ * Since the lifetimes of message senders and receivers may not always
+ * match, either side of the message channel may cancel pending
+ * responses which match its sender or recipient tags.
+ *
+ * For the above client, this might be done from an
+ * inner-window-destroyed observer, when its target scope is destroyed:
+ *
+ * observe(subject, topic, data) {
+ * if (topic == "inner-window-destroyed") {
+ * let innerWindowID = subject.QueryInterface(Ci.nsISupportsPRUint64).data;
+ *
+ * MessageChannel.abortResponses({ innerWindowID });
+ * }
+ * },
+ *
+ * From the parent, it may be done when its context is being destroyed:
+ *
+ * onDestroy() {
+ * MessageChannel.abortResponses({
+ * extensionID: this.extensionID,
+ * contextID: this.contextID,
+ * });
+ * },
+ *
+ */
+
+this.EXPORTED_SYMBOLS = ["MessageChannel"];
+
+/* globals MessageChannel */
+
+const Ci = Components.interfaces;
+const Cc = Components.classes;
+const Cu = Components.utils;
+const Cr = Components.results;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "PromiseUtils",
+ "resource://gre/modules/PromiseUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+ "resource://gre/modules/Task.jsm");
+
+
+/**
+ * Handles the mapping and dispatching of messages to their registered
+ * handlers. There is one broker per message manager and class of
+ * messages. Each class of messages is mapped to one native message
+ * name, e.g., "MessageChannel:Message", and is dispatched to handlers
+ * based on an internal message name, e.g., "Extension:ExecuteScript".
+ */
+class FilteringMessageManager {
+ /**
+ * @param {string} messageName
+ * The name of the native message this broker listens for.
+ * @param {function} callback
+ * A function which is called for each message after it has been
+ * mapped to its handler. The function receives two arguments:
+ *
+ * result:
+ * An object containing either a `handler` or an `error` property.
+ * If no error occurs, `handler` will be a matching handler that
+ * was registered by `addHandler`. Otherwise, the `error` property
+ * will contain an object describing the error.
+ *
+ * data:
+ * An object describing the message, as defined in
+ * `MessageChannel.addListener`.
+ */
+ constructor(messageName, callback, messageManager) {
+ this.messageName = messageName;
+ this.callback = callback;
+ this.messageManager = messageManager;
+
+ this.messageManager.addMessageListener(this.messageName, this);
+
+ this.handlers = new Map();
+ }
+
+ /**
+ * Receives a message from our message manager, maps it to a handler, and
+ * passes the result to our message callback.
+ */
+ receiveMessage({ data, target }) {
+ let handlers = Array.from(this.getHandlers(data.messageName, data.recipient));
+
+ let result = {};
+ if (handlers.length == 0) {
+ result.error = { result: MessageChannel.RESULT_NO_HANDLER,
+ message: "No matching message handler" };
+ } else if (handlers.length > 1) {
+ result.error = { result: MessageChannel.RESULT_MULTIPLE_HANDLERS,
+ message: `Multiple matching handlers for ${data.messageName}` };
+ } else {
+ result.handler = handlers[0];
+ }
+
+ data.target = target;
+ this.callback(result, data);
+ }
+
+ /**
+ * Iterates over all handlers for the given message name. If `recipient`
+ * is provided, only iterates over handlers whose filters match it.
+ *
+ * @param {string|number} messageName
+ * The message for which to return handlers.
+ * @param {object} recipient
+ * The recipient data on which to filter handlers.
+ */
+ * getHandlers(messageName, recipient) {
+ let handlers = this.handlers.get(messageName) || new Set();
+ for (let handler of handlers) {
+ if (MessageChannel.matchesFilter(handler.messageFilter, recipient)) {
+ yield handler;
+ }
+ }
+ }
+
+ /**
+ * Registers a handler for the given message.
+ *
+ * @param {string} messageName
+ * The internal message name for which to register the handler.
+ * @param {object} handler
+ * An opaque handler object. The object must have a `messageFilter`
+ * property on which to filter messages. Final dispatching is handled
+ * by the message callback passed to the constructor.
+ */
+ addHandler(messageName, handler) {
+ if (!this.handlers.has(messageName)) {
+ this.handlers.set(messageName, new Set());
+ }
+
+ this.handlers.get(messageName).add(handler);
+ }
+
+ /**
+ * Unregisters a handler for the given message.
+ *
+ * @param {string} messageName
+ * The internal message name for which to unregister the handler.
+ * @param {object} handler
+ * The handler object to unregister.
+ */
+ removeHandler(messageName, handler) {
+ this.handlers.get(messageName).delete(handler);
+ }
+}
+
+/**
+ * Manages mappings of message managers to their corresponding message
+ * brokers. Brokers are lazily created for each message manager the
+ * first time they are accessed. In the case of content frame message
+ * managers, they are also automatically destroyed when the frame
+ * unload event fires.
+ */
+class FilteringMessageManagerMap extends Map {
+ // Unfortunately, we can't use a WeakMap for this, because message
+ // managers do not support preserved wrappers.
+
+ /**
+ * @param {string} messageName
+ * The native message name passed to `FilteringMessageManager` constructors.
+ * @param {function} callback
+ * The message callback function passed to
+ * `FilteringMessageManager` constructors.
+ */
+ constructor(messageName, callback) {
+ super();
+
+ this.messageName = messageName;
+ this.callback = callback;
+ }
+
+ /**
+ * Returns, and possibly creates, a message broker for the given
+ * message manager.
+ *
+ * @param {nsIMessageSender} target
+ * The message manager for which to return a broker.
+ *
+ * @returns {FilteringMessageManager}
+ */
+ get(target) {
+ if (this.has(target)) {
+ return super.get(target);
+ }
+
+ let broker = new FilteringMessageManager(this.messageName, this.callback, target);
+ this.set(target, broker);
+
+ if (target instanceof Ci.nsIDOMEventTarget) {
+ let onUnload = event => {
+ target.removeEventListener("unload", onUnload);
+ this.delete(target);
+ };
+ target.addEventListener("unload", onUnload);
+ }
+
+ return broker;
+ }
+}
+
+const MESSAGE_MESSAGE = "MessageChannel:Message";
+const MESSAGE_RESPONSE = "MessageChannel:Response";
+
+let gChannelId = 0;
+
+this.MessageChannel = {
+ init() {
+ Services.obs.addObserver(this, "message-manager-close", false);
+ Services.obs.addObserver(this, "message-manager-disconnect", false);
+
+ this.messageManagers = new FilteringMessageManagerMap(
+ MESSAGE_MESSAGE, this._handleMessage.bind(this));
+
+ this.responseManagers = new FilteringMessageManagerMap(
+ MESSAGE_RESPONSE, this._handleResponse.bind(this));
+
+ /**
+ * Contains a list of pending responses, either waiting to be
+ * received or waiting to be sent. @see _addPendingResponse
+ */
+ this.pendingResponses = new Set();
+ },
+
+ RESULT_SUCCESS: 0,
+ RESULT_DISCONNECTED: 1,
+ RESULT_NO_HANDLER: 2,
+ RESULT_MULTIPLE_HANDLERS: 3,
+ RESULT_ERROR: 4,
+
+ REASON_DISCONNECTED: {
+ result: this.RESULT_DISCONNECTED,
+ message: "Message manager disconnected",
+ },
+
+ /**
+ * Returns true if the given `data` object matches the given `filter`
+ * object. The objects match if every property of `filter` is present
+ * in `data`, and the values in both objects are strictly equal.
+ *
+ * @param {object} filter
+ * The filter object to match against.
+ * @param {object} data
+ * The data object being matched.
+ * @returns {bool} True if the objects match.
+ */
+ matchesFilter(filter, data) {
+ return Object.keys(filter).every(key => {
+ return key in data && data[key] === filter[key];
+ });
+ },
+
+ /**
+ * Adds a message listener to the given message manager.
+ *
+ * @param {nsIMessageSender} target
+ * The message manager on which to listen.
+ * @param {string|number} messageName
+ * The name of the message to listen for.
+ * @param {MessageReceiver} handler
+ * The handler to dispatch to. Must be an object with the following
+ * properties:
+ *
+ * receiveMessage:
+ * A method which is called for each message received by the
+ * listener. The method takes one argument, an object, with the
+ * following properties:
+ *
+ * messageName:
+ * The internal message name, as passed to `sendMessage`.
+ *
+ * target:
+ * The message manager which received this message.
+ *
+ * channelId:
+ * The internal ID of the transaction, used to map responses to
+ * the original sender.
+ *
+ * sender:
+ * An object describing the sender, as passed to `sendMessage`.
+ *
+ * recipient:
+ * An object describing the recipient, as passed to
+ * `sendMessage`.
+ *
+ * data:
+ * The contents of the message, as passed to `sendMessage`.
+ *
+ * The method may return any structured-clone-compatible
+ * object, which will be returned as a response to the message
+ * sender. It may also instead return a `Promise`, the
+ * resolution or rejection value of which will likewise be
+ * returned to the message sender.
+ *
+ * messageFilter:
+ * An object containing arbitrary properties on which to filter
+ * received messages. Messages will only be dispatched to this
+ * object if the `recipient` object passed to `sendMessage`
+ * matches this filter, as determined by `matchesFilter`.
+ */
+ addListener(target, messageName, handler) {
+ this.messageManagers.get(target).addHandler(messageName, handler);
+ },
+
+ /**
+ * Removes a message listener from the given message manager.
+ *
+ * @param {nsIMessageSender} target
+ * The message manager on which to stop listening.
+ * @param {string|number} messageName
+ * The name of the message to stop listening for.
+ * @param {MessageReceiver} handler
+ * The handler to stop dispatching to.
+ */
+ removeListener(target, messageName, handler) {
+ this.messageManagers.get(target).removeListener(messageName, handler);
+ },
+
+ /**
+ * Sends a message via the given message manager. Returns a promise which
+ * resolves or rejects with the return value of the message receiver.
+ *
+ * The promise also rejects if there is no matching listener, or the other
+ * side of the message manager disconnects before the response is received.
+ *
+ * @param {nsIMessageSender} target
+ * The message manager on which to send the message.
+ * @param {string} messageName
+ * The name of the message to send, as passed to `addListener`.
+ * @param {object} data
+ * A structured-clone-compatible object to send to the message
+ * recipient.
+ * @param {object} [recipient]
+ * A structured-clone-compatible object to identify the message
+ * recipient. The object must match the `messageFilter` defined by
+ * recipients in order for the message to be received.
+ * @param {object} [sender]
+ * A structured-clone-compatible object to identify the message
+ * sender. This object may also be used as a filter to prematurely
+ * abort responses when the sender is being destroyed.
+ * @see `abortResponses`.
+ * @returns Promise
+ */
+ sendMessage(target, messageName, data, recipient = {}, sender = {}) {
+ let channelId = gChannelId++;
+ let message = { messageName, channelId, sender, recipient, data };
+
+ let deferred = PromiseUtils.defer();
+ deferred.messageFilter = {};
+ deferred.sender = recipient;
+ deferred.messageManager = target;
+
+ this._addPendingResponse(deferred);
+
+ // The channel ID is used as the message name when routing responses.
+ // Add a message listener to the response broker, and remove it once
+ // we've gotten (or canceled) a response.
+ let broker = this.responseManagers.get(target);
+ broker.addHandler(channelId, deferred);
+
+ let cleanup = () => {
+ broker.removeHandler(channelId, deferred);
+ };
+ deferred.promise.then(cleanup, cleanup);
+
+ target.sendAsyncMessage(MESSAGE_MESSAGE, message);
+ return deferred.promise;
+ },
+
+ /**
+ * Handles dispatching message callbacks from the message brokers to their
+ * appropriate `MessageReceivers`, and routing the responses back to the
+ * original senders.
+ *
+ * Each handler object is a `MessageReceiver` object as passed to
+ * `addListener`.
+ */
+ _handleMessage({ handler, error }, data) {
+ // The target passed to `receiveMessage` is sometimes a message manager
+ // owner instead of a message manager, so make sure to convert it to a
+ // message manager first if necessary.
+ let { target } = data;
+ if (!(target instanceof Ci.nsIMessageSender)) {
+ target = target.messageManager;
+ }
+
+ let deferred = {
+ sender: data.sender,
+ messageManager: target,
+ };
+ deferred.promise = new Promise((resolve, reject) => {
+ deferred.reject = reject;
+
+ if (handler) {
+ let result = handler.receiveMessage(data);
+ resolve(result);
+ } else {
+ reject(error);
+ }
+ }).then(
+ value => {
+ let response = {
+ result: this.RESULT_SUCCESS,
+ messageName: data.channelId,
+ recipient: {},
+ value,
+ };
+
+ target.sendAsyncMessage(MESSAGE_RESPONSE, response);
+ },
+ error => {
+ let response = {
+ result: this.RESULT_ERROR,
+ messageName: data.channelId,
+ recipient: {},
+ error,
+ };
+
+ if (error && typeof(error) == "object") {
+ if (error.result) {
+ response.result = error.result;
+ }
+ }
+
+ target.sendAsyncMessage(MESSAGE_RESPONSE, response);
+ });
+
+ this._addPendingResponse(deferred);
+ },
+
+ /**
+ * Handles message callbacks from the response brokers.
+ *
+ * Each handler object is a deferred object created by `sendMessage`, and
+ * should be resolved or rejected based on the contents of the response.
+ */
+ _handleResponse({ handler, error }, data) {
+ if (error) {
+ // If we have an error at this point, we have handler to report it to,
+ // so just log it.
+ Cu.reportError(error.message);
+ } else if (data.result === this.RESULT_SUCCESS) {
+ handler.resolve(data.value);
+ } else {
+ handler.reject(data);
+ }
+ },
+
+ /**
+ * Adds a pending response to the the `pendingResponses` list.
+ *
+ * The response object must be a deferred promise with the following
+ * properties:
+ *
+ * promise:
+ * The promise object which resolves or rejects when the response
+ * is no longer pending.
+ *
+ * reject:
+ * A function which, when called, causes the `promise` object to be
+ * rejected.
+ *
+ * sender:
+ * A sender object, as passed to `sendMessage.
+ *
+ * messageManager:
+ * The message manager the response will be sent or received on.
+ *
+ * When the promise resolves or rejects, it will be removed from the
+ * list.
+ *
+ * These values are used to clear pending responses when execution
+ * contexts are destroyed.
+ */
+ _addPendingResponse(deferred) {
+ let cleanup = () => {
+ this.pendingResponses.delete(deferred);
+ };
+ this.pendingResponses.add(deferred);
+ deferred.promise.then(cleanup, cleanup);
+ },
+
+ /**
+ * Aborts any pending message responses to senders matching the given
+ * filter.
+ *
+ * @param {object} sender
+ * The object on which to filter senders, as determined by
+ * `matchesFilter`.
+ * @param {object} [reason]
+ * An optional object describing the reason the response was aborted.
+ * Will be passed to the promise rejection handler of all aborted
+ * responses.
+ */
+ abortResponses(sender, reason = this.REASON_DISCONNECTED) {
+ for (let response of this.pendingResponses) {
+ if (this.matchesFilter(sender, response.sender)) {
+ response.reject(reason);
+ }
+ }
+ },
+
+ /**
+ * Aborts any pending message responses to the broker for the given
+ * message manager.
+ *
+ * @param {nsIMessageSender} target
+ * The message manager for which to abort brokers.
+ * @param {object} reason
+ * An object describing the reason the responses were aborted.
+ * Will be passed to the promise rejection handler of all aborted
+ * responses.
+ */
+ abortMessageManager(target, reason) {
+ for (let response of this.pendingResponses) {
+ if (response.messageManager === target) {
+ response.reject(reason);
+ }
+ }
+ },
+
+ observe(subject, topic, data) {
+ switch (topic) {
+ case "message-manager-close":
+ case "message-manager-disconnect":
+ try {
+ if (this.responseManagers.has(subject)) {
+ this.abortMessageManager(subject, this.REASON_DISCONNECTED);
+ }
+ } finally {
+ this.responseManagers.delete(subject);
+ this.messageManagers.delete(subject);
+ }
+ break;
+ }
+ },
+};
+
+MessageChannel.init();
--- a/toolkit/components/extensions/moz.build
+++ b/toolkit/components/extensions/moz.build
@@ -5,16 +5,17 @@
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
EXTRA_JS_MODULES += [
'Extension.jsm',
'ExtensionContent.jsm',
'ExtensionManagement.jsm',
'ExtensionStorage.jsm',
'ExtensionUtils.jsm',
+ 'MessageChannel.jsm',
'Schemas.jsm',
]
DIRS += ['schemas']
JAR_MANIFESTS += ['jar.mn']
MOCHITEST_MANIFESTS += ['test/mochitest/mochitest.ini']