The Tor Browser: toolkit/components/osfile/modules/osfile_async

toolkit/components/osfile/modules/osfile_async_front.jsm@129ffea94266 (annotated)

toolkit/components/osfile/modules/osfile_async_front.jsm

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* 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/. */
 /**
  * Asynchronous front-end for OS.File.
  *
  * This front-end is meant to be imported from the main thread. In turn,
  * it spawns one worker (perhaps more in the future) and delegates all
  * disk I/O to this worker.
  *
  * Documentation note: most of the functions and methods in this module
  * return promises. For clarity, we denote as follows a promise that may resolve
  * with type |A| and some value |value| or reject with type |B| and some
  * reason |reason|
  * @resolves {A} value
  * @rejects {B} reason
  */
 "use strict";
 this.EXPORTED_SYMBOLS = ["OS"];
 const Cu = Components.utils;
 const Ci = Components.interfaces;
 let SharedAll = {};
 Cu.import("resource://gre/modules/osfile/osfile_shared_allthreads.jsm", SharedAll);
 Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
 Cu.import("resource://gre/modules/Timer.jsm", this);
 XPCOMUtils.defineLazyModuleGetter(this, 'Deprecated',
   'resource://gre/modules/Deprecated.jsm');
 // Boilerplate, to simplify the transition to require()
 let LOG = SharedAll.LOG.bind(SharedAll, "Controller");
 let isTypedArray = SharedAll.isTypedArray;
 // The constructor for file errors.
 let SysAll = {};
 if (SharedAll.Constants.Win) {
   Cu.import("resource://gre/modules/osfile/osfile_win_allthreads.jsm", SysAll);
 } else if (SharedAll.Constants.libc) {
   Cu.import("resource://gre/modules/osfile/osfile_unix_allthreads.jsm", SysAll);
 } else {
   throw new Error("I am neither under Windows nor under a Posix system");
 }
 let OSError = SysAll.Error;
 let Type = SysAll.Type;
 let Path = {};
 Cu.import("resource://gre/modules/osfile/ospath.jsm", Path);
 // The library of promises.
 Cu.import("resource://gre/modules/Promise.jsm", this);
 Cu.import("resource://gre/modules/Task.jsm", this);
 // The implementation of communications
 Cu.import("resource://gre/modules/osfile/_PromiseWorker.jsm", this);
 Cu.import("resource://gre/modules/Services.jsm", this);
 Cu.import("resource://gre/modules/TelemetryStopwatch.jsm", this);
 Cu.import("resource://gre/modules/AsyncShutdown.jsm", this);
 let Native = Cu.import("resource://gre/modules/osfile/osfile_native.jsm", {});
 /**
  * Constructors for decoding standard exceptions
  * received from the worker.
  */
 const EXCEPTION_CONSTRUCTORS = {
   EvalError: function(error) {
     return new EvalError(error.message, error.fileName, error.lineNumber);
   },
   InternalError: function(error) {
     return new InternalError(error.message, error.fileName, error.lineNumber);
   },
   RangeError: function(error) {
     return new RangeError(error.message, error.fileName, error.lineNumber);
   },
   ReferenceError: function(error) {
     return new ReferenceError(error.message, error.fileName, error.lineNumber);
   },
   SyntaxError: function(error) {
     return new SyntaxError(error.message, error.fileName, error.lineNumber);
   },
   TypeError: function(error) {
     return new TypeError(error.message, error.fileName, error.lineNumber);
   },
   URIError: function(error) {
     return new URIError(error.message, error.fileName, error.lineNumber);
   },
   OSError: function(error) {
     return OS.File.Error.fromMsg(error);
   }
 };
 // It's possible for osfile.jsm to get imported before the profile is
 // set up. In this case, some path constants aren't yet available.
 // Here, we make them lazy loaders.
 function lazyPathGetter(constProp, dirKey) {
   return function () {
     let path;
     try {
       path = Services.dirsvc.get(dirKey, Ci.nsIFile).path;
       delete SharedAll.Constants.Path[constProp];
       SharedAll.Constants.Path[constProp] = path;
     } catch (ex) {
       // Ignore errors if the value still isn't available. Hopefully
       // the next access will return it.
     }
     return path;
   };
 }
 for (let [constProp, dirKey] of [
   ["localProfileDir", "ProfLD"],
   ["profileDir", "ProfD"],
   ["userApplicationDataDir", "UAppData"],
   ["winAppDataDir", "AppData"],
   ["winStartMenuProgsDir", "Progs"],
   ]) {
   if (constProp in SharedAll.Constants.Path) {
     continue;
   }
   LOG("Installing lazy getter for OS.Constants.Path." + constProp +
       " because it isn't defined and profile may not be loaded.");
   Object.defineProperty(SharedAll.Constants.Path, constProp, {
     get: lazyPathGetter(constProp, dirKey),
   });
 }
 /**
  * Return a shallow clone of the enumerable properties of an object.
  */
 let clone = SharedAll.clone;
 /**
  * Extract a shortened version of an object, fit for logging.
  *
  * This function returns a copy of the original object in which all
  * long strings, Arrays, TypedArrays, ArrayBuffers are removed and
  * replaced with placeholders. Use this function to sanitize objects
  * if you wish to log them or to keep them in memory.
  *
  * @param {*} obj The obj to shorten.
  * @return {*} array A shorter object, fit for logging.
  */
 function summarizeObject(obj) {
   if (!obj) {
     return null;
   }
   if (typeof obj == "string") {
     if (obj.length > 1024) {
       return {"Long string": obj.length};
     }
     return obj;
   }
   if (typeof obj == "object") {
     if (Array.isArray(obj)) {
       if (obj.length > 32) {
         return {"Long array": obj.length};
       }
       return [summarizeObject(k) for (k of obj)];
     }
     if ("byteLength" in obj) {
       // Assume TypedArray or ArrayBuffer
       return {"Binary Data": obj.byteLength};
     }
     let result = {};
     for (let k of Object.keys(obj)) {
       result[k] = summarizeObject(obj[k]);
     }
     return result;
   }
   return obj;
 }
 let Scheduler = {
   /**
    * |true| once we have sent at least one message to the worker.
    * This field is unaffected by resetting the worker.
    */
   launched: false,
   /**
    * |true| once shutdown has begun i.e. we should reject any
    * message, including resets.
    */
   shutdown: false,
   /**
    * A promise resolved once all operations are complete.
    *
    * This promise is never rejected and the result is always undefined.
    */
   queue: Promise.resolve(),
   /**
    * Miscellaneous debugging information
    */
   Debugging: {
     /**
      * The latest message sent and still waiting for a reply.
      */
     latestSent: undefined,
     /**
      * The latest reply received, or null if we are waiting for a reply.
      */
     latestReceived: undefined,
     /**
      * Number of messages sent to the worker. This includes the
      * initial SET_DEBUG, if applicable.
      */
     messagesSent: 0,
     /**
      * Total number of messages ever queued, including the messages
      * sent.
      */
     messagesQueued: 0,
     /**
      * Number of messages received from the worker.
      */
     messagesReceived: 0,
   },
   /**
    * A timer used to automatically shut down the worker after some time.
    */
   resetTimer: null,
   /**
    * The worker to which to send requests.
    *
    * If the worker has never been created or has been reset, this is a
    * fresh worker, initialized with osfile_async_worker.js.
    *
    * @type {PromiseWorker}
    */
   get worker() {
     if (!this._worker) {
       // Either the worker has never been created or it has been reset
       this._worker = new PromiseWorker(
 	"resource://gre/modules/osfile/osfile_async_worker.js", LOG);
     }
     return this._worker;
   },
   _worker: null,
   /**
    * Prepare to kill the OS.File worker after a few seconds.
    */
   restartTimer: function(arg) {
     let delay;
     try {
       delay = Services.prefs.getIntPref("osfile.reset_worker_delay");
     } catch(e) {
       // Don't auto-shutdown if we don't have a delay preference set.
       return;
     }
     if (this.resetTimer) {
       clearTimeout(this.resetTimer);
     }
     this.resetTimer = setTimeout(
       () => Scheduler.kill({reset: true, shutdown: false}),
       delay
     );
   },
   /**
    * Shutdown OS.File.
    *
    * @param {*} options
    * - {boolean} shutdown If |true|, reject any further request. Otherwise,
    *   further requests will resurrect the worker.
    * - {boolean} reset If |true|, instruct the worker to shutdown if this
    *   would not cause leaks. Otherwise, assume that the worker will be shutdown
    *   through some other mean.
    */
   kill: function({shutdown, reset}) {
     return Task.spawn(function*() {
       yield this.queue;
       // Enter critical section: no yield in this block
       // (we want to make sure that we remain the only
       // request in the queue).
       if (!this.launched || this.shutdown || !this._worker) {
         // Nothing to kill
         this.shutdown = this.shutdown || shutdown;
         this._worker = null;
         return null;
       }
       // Deactivate the queue, to ensure that no message is sent
       // to an obsolete worker (we reactivate it in the |finally|).
       let deferred = Promise.defer();
       this.queue = deferred.promise;
       // Exit critical section
       let message = ["Meta_shutdown", [reset]];
       try {
         Scheduler.latestReceived = [];
         Scheduler.latestSent = [Date.now(), ...message];
         let promise = this._worker.post(...message);
         // Wait for result
         let resources;
         try {
           resources = (yield promise).ok;
           Scheduler.latestReceived = [Date.now(), message];
         } catch (ex) {
           LOG("Could not dispatch Meta_reset", ex);
           // It's most likely a programmer error, but we'll assume that
           // the worker has been shutdown, as it's less risky than the
           // opposite stance.
           resources = {openedFiles: [], openedDirectoryIterators: [], killed: true};
           Scheduler.latestReceived = [Date.now(), message, ex];
         }
         let {openedFiles, openedDirectoryIterators, killed} = resources;
         if (!reset
           && (openedFiles && openedFiles.length
             || ( openedDirectoryIterators && openedDirectoryIterators.length))) {
           // The worker still holds resources. Report them.
           let msg = "";
           if (openedFiles.length > 0) {
             msg += "The following files are still open:\n" +
               openedFiles.join("\n");
           }
           if (openedDirectoryIterators.length > 0) {
             msg += "The following directory iterators are still open:\n" +
               openedDirectoryIterators.join("\n");
           }
           LOG("WARNING: File descriptors leaks detected.\n" + msg);
         }
         // Make sure that we do not leave an invalid |worker| around.
         if (killed || shutdown) {
           this._worker = null;
         }
         this.shutdown = shutdown;
         return resources;
       } finally {
         // Resume accepting messages. If we have set |shutdown| to |true|,
         // any pending/future request will be rejected. Otherwise, any
         // pending/future request will spawn a new worker if necessary.
         deferred.resolve();
       }
     }.bind(this));
   },
   /**
    * Push a task at the end of the queue.
    *
    * @param {function} code A function returning a Promise.
    * This function will be executed once all the previously
    * pushed tasks have completed.
    * @return {Promise} A promise with the same behavior as
    * the promise returned by |code|.
    */
   push: function(code) {
     let promise = this.queue.then(code);
     // By definition, |this.queue| can never reject.
     this.queue = promise.then(null, () => undefined);
     // Fork |promise| to ensure that uncaught errors are reported
     return promise.then(null, null);
   },
   /**
    * Post a message to the worker thread.
    *
    * @param {string} method The name of the method to call.
    * @param {...} args The arguments to pass to the method. These arguments
    * must be clonable.
    * @return {Promise} A promise conveying the result/error caused by
    * calling |method| with arguments |args|.
    */
   post: function post(method, ...args) {
     if (this.shutdown) {
       LOG("OS.File is not available anymore. The following request has been rejected.",
         method, args);
       return Promise.reject(new Error("OS.File has been shut down. Rejecting post to " + method));
     }
     let firstLaunch = !this.launched;
     this.launched = true;
     if (firstLaunch && SharedAll.Config.DEBUG) {
       // If we have delayed sending SET_DEBUG, do it now.
       this.worker.post("SET_DEBUG", [true]);
       Scheduler.Debugging.messagesSent++;
     }
     // By convention, the last argument of any message may be an |options| object.
     let options;
     let methodArgs = args[0];
     if (methodArgs) {
       options = methodArgs[methodArgs.length - 1];
     }
     Scheduler.Debugging.messagesQueued++;
     return this.push(Task.async(function*() {
       if (this.shutdown) {
 	LOG("OS.File is not available anymore. The following request has been rejected.",
 	  method, args);
 	throw new Error("OS.File has been shut down. Rejecting request to " + method);
       }
       // Update debugging information. As |args| may be quite
       // expensive, we only keep a shortened version of it.
       Scheduler.Debugging.latestReceived = null;
       Scheduler.Debugging.latestSent = [Date.now(), method, summarizeObject(methodArgs)];
       // Don't kill the worker just yet
       Scheduler.restartTimer();
       let data;
       let reply;
       let isError = false;
       try {
         try {
           data = yield this.worker.post(method, ...args);
         } finally {
           Scheduler.Debugging.messagesReceived++;
         }
         reply = data;
       } catch (error) {
         reply = error;
         isError = true;
         if (error instanceof PromiseWorker.WorkerError) {
           throw EXCEPTION_CONSTRUCTORS[error.data.exn || "OSError"](error.data);
         }
         if (error instanceof ErrorEvent) {
           let message = error.message;
           if (message == "uncaught exception: [object StopIteration]") {
             isError = false;
             throw StopIteration;
           }
           throw new Error(message, error.filename, error.lineno);
         }
         throw error;
       } finally {
         Scheduler.Debugging.latestSent = Scheduler.Debugging.latestSent.slice(0, 2);
         if (isError) {
           Scheduler.Debugging.latestReceived = [Date.now(), reply.message, reply.fileName, reply.lineNumber];
         } else {
           Scheduler.Debugging.latestReceived = [Date.now(), summarizeObject(reply)];
         }
         if (firstLaunch) {
           Scheduler._updateTelemetry();
         }
         Scheduler.restartTimer();
       }
       // Check for duration and return result.
       if (!options) {
         return data.ok;
       }
       // Check for options.outExecutionDuration.
       if (typeof options !== "object" ||
         !("outExecutionDuration" in options)) {
         return data.ok;
       }
       // If data.durationMs is not present, return data.ok (there was an
       // exception applying the method).
       if (!("durationMs" in data)) {
         return data.ok;
       }
       // Bug 874425 demonstrates that two successive calls to Date.now()
       // can actually produce an interval with negative duration.
       // We assume that this is due to an operation that is so short
       // that Date.now() is not monotonic, so we round this up to 0.
       let durationMs = Math.max(0, data.durationMs);
       // Accumulate (or initialize) outExecutionDuration
       if (typeof options.outExecutionDuration == "number") {
         options.outExecutionDuration += durationMs;
       } else {
         options.outExecutionDuration = durationMs;
       }
       return data.ok;
     }.bind(this)));
   },
   /**
    * Post Telemetry statistics.
    *
    * This is only useful on first launch.
    */
   _updateTelemetry: function() {
     let worker = this.worker;
     let workerTimeStamps = worker.workerTimeStamps;
     if (!workerTimeStamps) {
       // If the first call to OS.File results in an uncaught errors,
       // the timestamps are absent. As this case is a developer error,
       // let's not waste time attempting to extract telemetry from it.
       return;
     }
     let HISTOGRAM_LAUNCH = Services.telemetry.getHistogramById("OSFILE_WORKER_LAUNCH_MS");
     HISTOGRAM_LAUNCH.add(worker.workerTimeStamps.entered - worker.launchTimeStamp);
     let HISTOGRAM_READY = Services.telemetry.getHistogramById("OSFILE_WORKER_READY_MS");
     HISTOGRAM_READY.add(worker.workerTimeStamps.loaded - worker.launchTimeStamp);
   }
 };
 const PREF_OSFILE_LOG = "toolkit.osfile.log";
 const PREF_OSFILE_LOG_REDIRECT = "toolkit.osfile.log.redirect";
 /**
  * Safely read a PREF_OSFILE_LOG preference.
  * Returns a value read or, in case of an error, oldPref or false.
  *
  * @param bool oldPref
  *        An optional value that the DEBUG flag was set to previously.
  */
 function readDebugPref(prefName, oldPref = false) {
   let pref = oldPref;
   try {
     pref = Services.prefs.getBoolPref(prefName);
   } catch (x) {
     // In case of an error when reading a pref keep it as is.
   }
   // If neither pref nor oldPref were set, default it to false.
   return pref;
 };
 /**
  * Listen to PREF_OSFILE_LOG changes and update gShouldLog flag
  * appropriately.
  */
 Services.prefs.addObserver(PREF_OSFILE_LOG,
   function prefObserver(aSubject, aTopic, aData) {
     SharedAll.Config.DEBUG = readDebugPref(PREF_OSFILE_LOG, SharedAll.Config.DEBUG);
     if (Scheduler.launched) {
       // Don't start the worker just to set this preference.
       Scheduler.post("SET_DEBUG", [SharedAll.Config.DEBUG]);
     }
   }, false);
 SharedAll.Config.DEBUG = readDebugPref(PREF_OSFILE_LOG, false);
 Services.prefs.addObserver(PREF_OSFILE_LOG_REDIRECT,
   function prefObserver(aSubject, aTopic, aData) {
     SharedAll.Config.TEST = readDebugPref(PREF_OSFILE_LOG_REDIRECT, OS.Shared.TEST);
   }, false);
 SharedAll.Config.TEST = readDebugPref(PREF_OSFILE_LOG_REDIRECT, false);
 /**
  * If |true|, use the native implementaiton of OS.File methods
  * whenever possible. Otherwise, force the use of the JS version.
  */
 let nativeWheneverAvailable = true;
 const PREF_OSFILE_NATIVE = "toolkit.osfile.native";
 Services.prefs.addObserver(PREF_OSFILE_NATIVE,
   function prefObserver(aSubject, aTopic, aData) {
     nativeWheneverAvailable = readDebugPref(PREF_OSFILE_NATIVE, nativeWheneverAvailable);
   }, false);
 // Update worker's DEBUG flag if it's true.
 // Don't start the worker just for this, though.
 if (SharedAll.Config.DEBUG && Scheduler.launched) {
   Scheduler.post("SET_DEBUG", [true]);
 }
 // Observer topics used for monitoring shutdown
 const WEB_WORKERS_SHUTDOWN_TOPIC = "web-workers-shutdown";
 // Preference used to configure test shutdown observer.
 const PREF_OSFILE_TEST_SHUTDOWN_OBSERVER =
   "toolkit.osfile.test.shutdown.observer";
 AsyncShutdown.webWorkersShutdown.addBlocker(
   "OS.File: flush pending requests, warn about unclosed files, shut down service.",
   () => Scheduler.kill({reset: false, shutdown: true})
 );
 // Attaching an observer for PREF_OSFILE_TEST_SHUTDOWN_OBSERVER to enable or
 // disable the test shutdown event observer.
 // Note: By default the PREF_OSFILE_TEST_SHUTDOWN_OBSERVER is unset.
 // Note: This is meant to be used for testing purposes only.
 Services.prefs.addObserver(PREF_OSFILE_TEST_SHUTDOWN_OBSERVER,
   function prefObserver() {
     // The temporary phase topic used to trigger the unclosed
     // phase warning.
     let TOPIC = null;
     try {
       TOPIC = Services.prefs.getCharPref(
         PREF_OSFILE_TEST_SHUTDOWN_OBSERVER);
     } catch (x) {
     }
     if (TOPIC) {
       // Generate a phase, add a blocker.
       // Note that this can work only if AsyncShutdown itself has been
       // configured for testing by the testsuite.
       let phase = AsyncShutdown._getPhase(TOPIC);
       phase.addBlocker(
         "(for testing purposes) OS.File: warn about unclosed files",
         () => Scheduler.kill({shutdown: false, reset: false})
       );
     }
   }, false);
 /**
  * Representation of a file, with asynchronous methods.
  *
  * @param {*} fdmsg The _message_ representing the platform-specific file
  * handle.
  *
  * @constructor
  */
 let File = function File(fdmsg) {
   // FIXME: At the moment, |File| does not close on finalize
   // (see bug 777715)
   this._fdmsg = fdmsg;
   this._closeResult = null;
   this._closed = null;
 };
 File.prototype = {
   /**
    * Close a file asynchronously.
    *
    * This method is idempotent.
    *
    * @return {promise}
    * @resolves {null}
    * @rejects {OS.File.Error}
    */
   close: function close() {
     if (this._fdmsg != null) {
       let msg = this._fdmsg;
       this._fdmsg = null;
       return this._closeResult =
         Scheduler.post("File_prototype_close", [msg], this);
     }
     return this._closeResult;
   },
   /**
    * Fetch information about the file.
    *
    * @return {promise}
    * @resolves {OS.File.Info} The latest information about the file.
    * @rejects {OS.File.Error}
    */
   stat: function stat() {
     return Scheduler.post("File_prototype_stat", [this._fdmsg], this).then(
       File.Info.fromMsg
     );
   },
   /**
    * Set the last access and modification date of the file.
    * The time stamp resolution is 1 second at best, but might be worse
    * depending on the platform.
    *
    * @return {promise}
    * @rejects {TypeError}
    * @rejects {OS.File.Error}
    */
   setDates: function setDates(accessDate, modificationDate) {
     return Scheduler.post("File_prototype_setDates",
                           [this._fdmsg, accessDate, modificationDate], this);
   },
   /**
    * Read a number of bytes from the file and into a buffer.
    *
    * @param {Typed array | C pointer} buffer This buffer will be
    * modified by another thread. Using this buffer before the |read|
    * operation has completed is a BAD IDEA.
    * @param {JSON} options
    *
    * @return {promise}
    * @resolves {number} The number of bytes effectively read.
    * @rejects {OS.File.Error}
    */
   readTo: function readTo(buffer, options = {}) {
     // If |buffer| is a typed array and there is no |bytes| options, we
     // need to extract the |byteLength| now, as it will be lost by
     // communication.
     // Options might be a nullish value, so better check for that before using
     // the |in| operator.
     if (isTypedArray(buffer) && !(options && "bytes" in options)) {
       // Preserve reference to option |outExecutionDuration|, if it is passed.
       options = clone(options, ["outExecutionDuration"]);
       options.bytes = buffer.byteLength;
     }
     // Note: Type.void_t.out_ptr.toMsg ensures that
     // - the buffer is effectively shared (not neutered) between both
     //   threads;
     // - we take care of any |byteOffset|.
     return Scheduler.post("File_prototype_readTo",
       [this._fdmsg,
        Type.void_t.out_ptr.toMsg(buffer),
        options],
        buffer/*Ensure that |buffer| is not gc-ed*/);
   },
   /**
    * Write bytes from a buffer to this file.
    *
    * Note that, by default, this function may perform several I/O
    * operations to ensure that the buffer is fully written.
    *
    * @param {Typed array | C pointer} buffer The buffer in which the
    * the bytes are stored. The buffer must be large enough to
    * accomodate |bytes| bytes. Using the buffer before the operation
    * is complete is a BAD IDEA.
    * @param {*=} options Optionally, an object that may contain the
    * following fields:
    * - {number} bytes The number of |bytes| to write from the buffer. If
    * unspecified, this is |buffer.byteLength|. Note that |bytes| is required
    * if |buffer| is a C pointer.
    *
    * @return {number} The number of bytes actually written.
    */
   write: function write(buffer, options = {}) {
     // If |buffer| is a typed array and there is no |bytes| options,
     // we need to extract the |byteLength| now, as it will be lost
     // by communication.
     // Options might be a nullish value, so better check for that before using
     // the |in| operator.
     if (isTypedArray(buffer) && !(options && "bytes" in options)) {
       // Preserve reference to option |outExecutionDuration|, if it is passed.
       options = clone(options, ["outExecutionDuration"]);
       options.bytes = buffer.byteLength;
     }
     // Note: Type.void_t.out_ptr.toMsg ensures that
     // - the buffer is effectively shared (not neutered) between both
     //   threads;
     // - we take care of any |byteOffset|.
     return Scheduler.post("File_prototype_write",
       [this._fdmsg,
        Type.void_t.in_ptr.toMsg(buffer),
        options],
        buffer/*Ensure that |buffer| is not gc-ed*/);
   },
   /**
    * Read bytes from this file to a new buffer.
    *
    * @param {number=} bytes If unspecified, read all the remaining bytes from
    * this file. If specified, read |bytes| bytes, or less if the file does not
    * contain that many bytes.
    * @param {JSON} options
    * @return {promise}
    * @resolves {Uint8Array} An array containing the bytes read.
    */
   read: function read(nbytes, options = {}) {
     let promise = Scheduler.post("File_prototype_read",
       [this._fdmsg,
        nbytes, options]);
     return promise.then(
       function onSuccess(data) {
         return new Uint8Array(data.buffer, data.byteOffset, data.byteLength);
       });
   },
   /**
    * Return the current position in the file, as bytes.
    *
    * @return {promise}
    * @resolves {number} The current position in the file,
    * as a number of bytes since the start of the file.
    */
   getPosition: function getPosition() {
     return Scheduler.post("File_prototype_getPosition",
       [this._fdmsg]);
   },
   /**
    * Set the current position in the file, as bytes.
    *
    * @param {number} pos A number of bytes.
    * @param {number} whence The reference position in the file,
    * which may be either POS_START (from the start of the file),
    * POS_END (from the end of the file) or POS_CUR (from the
    * current position in the file).
    *
    * @return {promise}
    */
   setPosition: function setPosition(pos, whence) {
     return Scheduler.post("File_prototype_setPosition",
       [this._fdmsg, pos, whence]);
   },
   /**
    * Flushes the file's buffers and causes all buffered data
    * to be written.
    * Disk flushes are very expensive and therefore should be used carefully,
    * sparingly and only in scenarios where it is vital that data survives
    * system crashes. Even though the function will be executed off the
    * main-thread, it might still affect the overall performance of any running
    * application.
    *
    * @return {promise}
    */
   flush: function flush() {
     return Scheduler.post("File_prototype_flush",
       [this._fdmsg]);
   },
   /**
    * Set the file's access permissions.  Without any options, the
    * permissions are set to an approximation of what they would have
    * been if the file had been created in its current directory in the
    * "most typical" fashion for the operating system.  In the current
    * implementation, this means that on Unix-like systems (including
    * Android, B2G, etc) we set the POSIX file mode to (0666 & ~umask),
    * and on Windows, we do nothing.
    *
    * This operation is likely to fail if applied to a file that was
    * not created by the currently running program (more precisely,
    * if it was created by a program running under a different OS-level
    * user account).  It may also fail, or silently do nothing, if the
    * filesystem containing the file does not support access permissions.
    *
    * @param {*=} options
    * - {number} unixMode     If present, the POSIX file mode is set to exactly
    *                         this value, unless |unixHonorUmask| is also
    *                         present.
    * - {bool} unixHonorUmask If true, any |unixMode| value is modified by the
    *                         process umask, as open() would have done.
    */
   setPermissions: function setPermissions(options = {}) {
     return Scheduler.post("File_prototype_setPermissions",
                           [this._fdmsg, options]);
   }
 };
 /**
  * Open a file asynchronously.
  *
  * @return {promise}
  * @resolves {OS.File}
  * @rejects {OS.Error}
  */
 File.open = function open(path, mode, options) {
   return Scheduler.post(
     "open", [Type.path.toMsg(path), mode, options],
     path
   ).then(
     function onSuccess(msg) {
       return new File(msg);
     }
   );
 };
 /**
  * Creates and opens a file with a unique name. By default, generate a random HEX number and use it to create a unique new file name.
  *
  * @param {string} path The path to the file.
  * @param {*=} options Additional options for file opening. This
  * implementation interprets the following fields:
  *
  * - {number} humanReadable If |true|, create a new filename appending a decimal number. ie: filename-1.ext, filename-2.ext.
  *  If |false| use HEX numbers ie: filename-A65BC0.ext
  * - {number} maxReadableNumber Used to limit the amount of tries after a failed
  *  file creation. Default is 20.
  *
  * @return {Object} contains A file object{file} and the path{path}.
  * @throws {OS.File.Error} If the file could not be opened.
  */
 File.openUnique = function openUnique(path, options) {
   return Scheduler.post(
       "openUnique", [Type.path.toMsg(path), options],
       path
     ).then(
     function onSuccess(msg) {
       return {
         path: msg.path,
         file: new File(msg.file)
       };
     }
   );
 };
 /**
  * Get the information on the file.
  *
  * @return {promise}
  * @resolves {OS.File.Info}
  * @rejects {OS.Error}
  */
 File.stat = function stat(path, options) {
   return Scheduler.post(
     "stat", [Type.path.toMsg(path), options],
     path).then(File.Info.fromMsg);
 };
 /**
  * Set the last access and modification date of the file.
  * The time stamp resolution is 1 second at best, but might be worse
  * depending on the platform.
  *
  * @return {promise}
  * @rejects {TypeError}
  * @rejects {OS.File.Error}
  */
 File.setDates = function setDates(path, accessDate, modificationDate) {
   return Scheduler.post("setDates",
                         [Type.path.toMsg(path), accessDate, modificationDate],
                         this);
 };
 /**
  * Set the file's access permissions.  Without any options, the
  * permissions are set to an approximation of what they would have
  * been if the file had been created in its current directory in the
  * "most typical" fashion for the operating system.  In the current
  * implementation, this means that on Unix-like systems (including
  * Android, B2G, etc) we set the POSIX file mode to (0666 & ~umask),
  * and on Windows, we do nothing.
  *
  * This operation is likely to fail if applied to a file that was
  * not created by the currently running program (more precisely,
  * if it was created by a program running under a different OS-level
  * user account).  It may also fail, or silently do nothing, if the
  * filesystem containing the file does not support access permissions.
  *
  * @param {string} path   The path to the file.
  *
  * @param {*=} options
  * - {number} unixMode     If present, the POSIX file mode is set to exactly
  *                         this value, unless |unixHonorUmask| is also
  *                         present.
  * - {bool} unixHonorUmask If true, any |unixMode| value is modified by the
  *                         process umask, as open() would have done.
  */
 File.setPermissions = function setPermissions(path, options = {}) {
   return Scheduler.post("setPermissions",
                         [Type.path.toMsg(path), options]);
 };
 /**
  * Fetch the current directory
  *
  * @return {promise}
  * @resolves {string} The current directory, as a path usable with OS.Path
  * @rejects {OS.Error}
  */
 File.getCurrentDirectory = function getCurrentDirectory() {
   return Scheduler.post(
     "getCurrentDirectory"
   ).then(Type.path.fromMsg);
 };
 /**
  * Change the current directory
  *
  * @param {string} path The OS-specific path to the current directory.
  * You should use the methods of OS.Path and the constants of OS.Constants.Path
  * to build OS-specific paths in a portable manner.
  *
  * @return {promise}
  * @resolves {null}
  * @rejects {OS.Error}
  */
 File.setCurrentDirectory = function setCurrentDirectory(path) {
   return Scheduler.post(
     "setCurrentDirectory", [Type.path.toMsg(path)], path
   );
 };
 /**
  * Copy a file to a destination.
  *
  * @param {string} sourcePath The platform-specific path at which
  * the file may currently be found.
  * @param {string} destPath The platform-specific path at which the
  * file should be copied.
  * @param {*=} options An object which may contain the following fields:
  *
  * @option {bool} noOverwrite - If true, this function will fail if
  * a file already exists at |destPath|. Otherwise, if this file exists,
  * it will be erased silently.
  *
  * @rejects {OS.File.Error} In case of any error.
  *
  * General note: The behavior of this function is defined only when
  * it is called on a single file. If it is called on a directory, the
  * behavior is undefined and may not be the same across all platforms.
  *
  * General note: The behavior of this function with respect to metadata
  * is unspecified. Metadata may or may not be copied with the file. The
  * behavior may not be the same across all platforms.
 */
 File.copy = function copy(sourcePath, destPath, options) {
   return Scheduler.post("copy", [Type.path.toMsg(sourcePath),
     Type.path.toMsg(destPath), options], [sourcePath, destPath]);
 };
 /**
  * Move a file to a destination.
  *
  * @param {string} sourcePath The platform-specific path at which
  * the file may currently be found.
  * @param {string} destPath The platform-specific path at which the
  * file should be moved.
  * @param {*=} options An object which may contain the following fields:
  *
  * @option {bool} noOverwrite - If set, this function will fail if
  * a file already exists at |destPath|. Otherwise, if this file exists,
  * it will be erased silently.
  *
  * @returns {Promise}
  * @rejects {OS.File.Error} In case of any error.
  *
  * General note: The behavior of this function is defined only when
  * it is called on a single file. If it is called on a directory, the
  * behavior is undefined and may not be the same across all platforms.
  *
  * General note: The behavior of this function with respect to metadata
  * is unspecified. Metadata may or may not be moved with the file. The
  * behavior may not be the same across all platforms.
  */
 File.move = function move(sourcePath, destPath, options) {
   return Scheduler.post("move", [Type.path.toMsg(sourcePath),
     Type.path.toMsg(destPath), options], [sourcePath, destPath]);
 };
 /**
  * Create a symbolic link to a source.
  *
  * @param {string} sourcePath The platform-specific path to which
  * the symbolic link should point.
  * @param {string} destPath The platform-specific path at which the
  * symbolic link should be created.
  *
  * @returns {Promise}
  * @rejects {OS.File.Error} In case of any error.
  */
 if (!SharedAll.Constants.Win) {
   File.unixSymLink = function unixSymLink(sourcePath, destPath) {
     return Scheduler.post("unixSymLink", [Type.path.toMsg(sourcePath),
       Type.path.toMsg(destPath)], [sourcePath, destPath]);
   };
 }
 /**
  * Gets the number of bytes available on disk to the current user.
  *
  * @param {string} Platform-specific path to a directory on the disk to
  * query for free available bytes.
  *
  * @return {number} The number of bytes available for the current user.
  * @throws {OS.File.Error} In case of any error.
  */
 File.getAvailableFreeSpace = function getAvailableFreeSpace(sourcePath) {
   return Scheduler.post("getAvailableFreeSpace",
     [Type.path.toMsg(sourcePath)], sourcePath
   ).then(Type.uint64_t.fromMsg);
 };
 /**
  * Remove an empty directory.
  *
  * @param {string} path The name of the directory to remove.
  * @param {*=} options Additional options.
  *   - {bool} ignoreAbsent If |true|, do not fail if the
  *     directory does not exist yet.
  */
 File.removeEmptyDir = function removeEmptyDir(path, options) {
   return Scheduler.post("removeEmptyDir",
     [Type.path.toMsg(path), options], path);
 };
 /**
  * Remove an existing file.
  *
  * @param {string} path The name of the file.
  */
 File.remove = function remove(path) {
   return Scheduler.post("remove",
     [Type.path.toMsg(path)]);
 };
 /**
  * Create a directory and, optionally, its parent directories.
  *
  * @param {string} path The name of the directory.
  * @param {*=} options Additional options.
  *
  * - {string} from If specified, the call to |makeDir| creates all the
  * ancestors of |path| that are descendants of |from|. Note that |path|
  * must be a descendant of |from|, and that |from| and its existing
  * subdirectories present in |path|  must be user-writeable.
  * Example:
  *   makeDir(Path.join(profileDir, "foo", "bar"), { from: profileDir });
  *  creates directories profileDir/foo, profileDir/foo/bar
  * - {bool} ignoreExisting If |false|, throw an error if the directory
  * already exists. |true| by default. Ignored if |from| is specified.
  * - {number} unixMode Under Unix, if specified, a file creation mode,
  * as per libc function |mkdir|. If unspecified, dirs are
  * created with a default mode of 0700 (dir is private to
  * the user, the user can read, write and execute). Ignored under Windows
  * or if the file system does not support file creation modes.
  * - {C pointer} winSecurity Under Windows, if specified, security
  * attributes as per winapi function |CreateDirectory|. If
  * unspecified, use the default security descriptor, inherited from
  * the parent directory. Ignored under Unix or if the file system
  * does not support security descriptors.
  */
 File.makeDir = function makeDir(path, options) {
   return Scheduler.post("makeDir",
     [Type.path.toMsg(path), options], path);
 };
 /**
  * Return the contents of a file
  *
  * @param {string} path The path to the file.
  * @param {number=} bytes Optionally, an upper bound to the number of bytes
  * to read. DEPRECATED - please use options.bytes instead.
  * @param {JSON} options Additional options.
  * - {boolean} sequential A flag that triggers a population of the page cache
  * with data from a file so that subsequent reads from that file would not
  * block on disk I/O. If |true| or unspecified, inform the system that the
  * contents of the file will be read in order. Otherwise, make no such
  * assumption. |true| by default.
  * - {number} bytes An upper bound to the number of bytes to read.
  * - {string} compression If "lz4" and if the file is compressed using the lz4
  * compression algorithm, decompress the file contents on the fly.
  *
  * @resolves {Uint8Array} A buffer holding the bytes
  * read from the file.
  */
 File.read = function read(path, bytes, options = {}) {
   if (typeof bytes == "object") {
     // Passing |bytes| as an argument is deprecated.
     // We should now be passing it as a field of |options|.
     options = bytes || {};
   } else {
     options = clone(options, ["outExecutionDuration"]);
     if (typeof bytes != "undefined") {
       options.bytes = bytes;
     }
   }
   if (options.compression || !nativeWheneverAvailable) {
     // We need to use the JS implementation.
     let promise = Scheduler.post("read",
       [Type.path.toMsg(path), bytes, options], path);
     return promise.then(
       function onSuccess(data) {
         if (typeof data == "string") {
           return data;
         }
         return new Uint8Array(data.buffer, data.byteOffset, data.byteLength);
       });
   }
   // Otherwise, use the native implementation.
   return Scheduler.push(() => Native.read(path, options));
 };
 /**
  * Find outs if a file exists.
  *
  * @param {string} path The path to the file.
  *
  * @return {bool} true if the file exists, false otherwise.
  */
 File.exists = function exists(path) {
   return Scheduler.post("exists",
     [Type.path.toMsg(path)], path);
 };
 /**
  * Write a file, atomically.
  *
  * By opposition to a regular |write|, this operation ensures that,
  * until the contents are fully written, the destination file is
  * not modified.
  *
  * Limitation: In a few extreme cases (hardware failure during the
  * write, user unplugging disk during the write, etc.), data may be
  * corrupted. If your data is user-critical (e.g. preferences,
  * application data, etc.), you may wish to consider adding options
  * |tmpPath| and/or |flush| to reduce the likelihood of corruption, as
  * detailed below. Note that no combination of options can be
  * guaranteed to totally eliminate the risk of corruption.
  *
  * @param {string} path The path of the file to modify.
  * @param {Typed Array | C pointer} buffer A buffer containing the bytes to write.
  * @param {*=} options Optionally, an object determining the behavior
  * of this function. This object may contain the following fields:
  * - {number} bytes The number of bytes to write. If unspecified,
  * |buffer.byteLength|. Required if |buffer| is a C pointer.
  * - {string} tmpPath If |null| or unspecified, write all data directly
  * to |path|. If specified, write all data to a temporary file called
  * |tmpPath| and, once this write is complete, rename the file to
  * replace |path|. Performing this additional operation is a little
  * slower but also a little safer.
  * - {bool} noOverwrite - If set, this function will fail if a file already
  * exists at |path|.
  * - {bool} flush - If |false| or unspecified, return immediately once the
  * write is complete. If |true|, before writing, force the operating system
  * to write its internal disk buffers to the disk. This is considerably slower
  * (not just for the application but for the whole system) but also safer:
  * if the system shuts down improperly (typically due to a kernel freeze
  * or a power failure) or if the device is disconnected before the buffer
  * is flushed, the file has more chances of not being corrupted.
  * - {string} backupTo - If specified, backup the destination file as |backupTo|.
  * Note that this function renames the destination file before overwriting it.
  * If the process or the operating system freezes or crashes
  * during the short window between these operations,
  * the destination file will have been moved to its backup.
  *
  * @return {promise}
  * @resolves {number} The number of bytes actually written.
  */
 File.writeAtomic = function writeAtomic(path, buffer, options = {}) {
   // Copy |options| to avoid modifying the original object but preserve the
   // reference to |outExecutionDuration| option if it is passed.
   options = clone(options, ["outExecutionDuration"]);
   // As options.tmpPath is a path, we need to encode it as |Type.path| message
   if ("tmpPath" in options) {
     options.tmpPath = Type.path.toMsg(options.tmpPath);
   };
   if (isTypedArray(buffer) && (!("bytes" in options))) {
     options.bytes = buffer.byteLength;
   };
   // Note: Type.void_t.out_ptr.toMsg ensures that
   // - the buffer is effectively shared (not neutered) between both
   //   threads;
   // - we take care of any |byteOffset|.
   let refObj = {};
   TelemetryStopwatch.start("OSFILE_WRITEATOMIC_JANK_MS", refObj);
   let promise = Scheduler.post("writeAtomic",
     [Type.path.toMsg(path),
      Type.void_t.in_ptr.toMsg(buffer),
      options], [options, buffer]);
   TelemetryStopwatch.finish("OSFILE_WRITEATOMIC_JANK_MS", refObj);
   return promise;
 };
 File.removeDir = function(path, options = {}) {
   return Scheduler.post("removeDir",
     [Type.path.toMsg(path), options], path);
 };
 /**
  * Information on a file, as returned by OS.File.stat or
  * OS.File.prototype.stat
  *
  * @constructor
  */
 File.Info = function Info(value) {
   // Note that we can't just do this[k] = value[k] because our
   // prototype defines getters for all of these fields.
   for (let k in value) {
     if (k != "creationDate") {
       Object.defineProperty(this, k, {value: value[k]});
     }
   }
   Object.defineProperty(this, "_deprecatedCreationDate", {value: value["creationDate"]});
 };
 File.Info.prototype = SysAll.AbstractInfo.prototype;
 // Deprecated
 Object.defineProperty(File.Info.prototype, "creationDate", {
   get: function creationDate() {
     Deprecated.warning("Field 'creationDate' is deprecated.", "https://developer.mozilla.org/en-US/docs/JavaScript_OS.File/OS.File.Info#Cross-platform_Attributes");
     return this._deprecatedCreationDate;
   }
 });
 File.Info.fromMsg = function fromMsg(value) {
   return new File.Info(value);
 };
 /**
  * Get worker's current DEBUG flag.
  * Note: This is used for testing purposes.
  */
 File.GET_DEBUG = function GET_DEBUG() {
   return Scheduler.post("GET_DEBUG");
 };
 /**
  * Iterate asynchronously through a directory
  *
  * @constructor
  */
 let DirectoryIterator = function DirectoryIterator(path, options) {
   /**
    * Open the iterator on the worker thread
    *
    * @type {Promise}
    * @resolves {*} A message accepted by the methods of DirectoryIterator
    * in the worker thread
    * @rejects {StopIteration} If all entries have already been visited
    * or the iterator has been closed.
    */
   this.__itmsg = Scheduler.post(
     "new_DirectoryIterator", [Type.path.toMsg(path), options],
     path
   );
   this._isClosed = false;
 };
 DirectoryIterator.prototype = {
   iterator: function () this,
   __iterator__: function () this,
   // Once close() is called, _itmsg should reject with a
   // StopIteration. However, we don't want to create the promise until
   // it's needed because it might never be used. In that case, we
   // would get a warning on the console.
   get _itmsg() {
     if (!this.__itmsg) {
       this.__itmsg = Promise.reject(StopIteration);
     }
     return this.__itmsg;
   },
   /**
    * Determine whether the directory exists.
    *
    * @resolves {boolean}
    */
   exists: function exists() {
     return this._itmsg.then(
       function onSuccess(iterator) {
         return Scheduler.post("DirectoryIterator_prototype_exists", [iterator]);
       }
     );
   },
   /**
    * Get the next entry in the directory.
    *
    * @return {Promise}
    * @resolves {OS.File.Entry}
    * @rejects {StopIteration} If all entries have already been visited.
    */
   next: function next() {
     let self = this;
     let promise = this._itmsg;
     // Get the iterator, call _next
     promise = promise.then(
       function withIterator(iterator) {
         return self._next(iterator);
       });
     return promise;
   },
   /**
    * Get several entries at once.
    *
    * @param {number=} length If specified, the number of entries
    * to return. If unspecified, return all remaining entries.
    * @return {Promise}
    * @resolves {Array} An array containing the |length| next entries.
    */
   nextBatch: function nextBatch(size) {
     if (this._isClosed) {
       return Promise.resolve([]);
     }
     let promise = this._itmsg;
     promise = promise.then(
       function withIterator(iterator) {
         return Scheduler.post("DirectoryIterator_prototype_nextBatch", [iterator, size]);
       });
     promise = promise.then(
       function withEntries(array) {
         return array.map(DirectoryIterator.Entry.fromMsg);
       });
     return promise;
   },
   /**
    * Apply a function to all elements of the directory sequentially.
    *
    * @param {Function} cb This function will be applied to all entries
    * of the directory. It receives as arguments
    *  - the OS.File.Entry corresponding to the entry;
    *  - the index of the entry in the enumeration;
    *  - the iterator itself - return |iterator.close()| to stop the loop.
    *
    * If the callback returns a promise, iteration waits until the
    * promise is resolved before proceeding.
    *
    * @return {Promise} A promise resolved once the loop has reached
    * its end.
    */
   forEach: function forEach(cb, options) {
     if (this._isClosed) {
       return Promise.resolve();
     }
     let self = this;
     let position = 0;
     let iterator;
     // Grab iterator
     let promise = this._itmsg.then(
       function(aIterator) {
         iterator = aIterator;
       }
     );
     // Then iterate
     let loop = function loop() {
       if (self._isClosed) {
         return Promise.resolve();
       }
       return self._next(iterator).then(
         function onSuccess(value) {
           return Promise.resolve(cb(value, position++, self)).then(loop);
         },
         function onFailure(reason) {
           if (reason == StopIteration) {
             return;
           }
           throw reason;
         }
       );
     };
     return promise.then(loop);
   },
   /**
    * Auxiliary method: fetch the next item
    *
    * @rejects {StopIteration} If all entries have already been visited
    * or the iterator has been closed.
    */
   _next: function _next(iterator) {
     if (this._isClosed) {
       return this._itmsg;
     }
     let self = this;
     let promise = Scheduler.post("DirectoryIterator_prototype_next", [iterator]);
     promise = promise.then(
       DirectoryIterator.Entry.fromMsg,
       function onReject(reason) {
         if (reason == StopIteration) {
           self.close();
           throw StopIteration;
         }
         throw reason;
       });
     return promise;
   },
   /**
    * Close the iterator
    */
   close: function close() {
     if (this._isClosed) {
       return Promise.resolve();
     }
     this._isClosed = true;
     let self = this;
     return this._itmsg.then(
       function withIterator(iterator) {
         // Set __itmsg to null so that the _itmsg getter returns a
         // rejected StopIteration promise if it's ever used.
         self.__itmsg = null;
         return Scheduler.post("DirectoryIterator_prototype_close", [iterator]);
       }
     );
   }
 };
 DirectoryIterator.Entry = function Entry(value) {
   return value;
 };
 DirectoryIterator.Entry.prototype = Object.create(SysAll.AbstractEntry.prototype);
 DirectoryIterator.Entry.fromMsg = function fromMsg(value) {
   return new DirectoryIterator.Entry(value);
 };
 File.resetWorker = function() {
   return Task.spawn(function*() {
     let resources = yield Scheduler.kill({shutdown: false, reset: true});
     if (resources && !resources.killed) {
         throw new Error("Could not reset worker, this would leak file descriptors: " + JSON.stringify(resources));
     }
   });
 };
 // Constants
 File.POS_START = SysAll.POS_START;
 File.POS_CURRENT = SysAll.POS_CURRENT;
 File.POS_END = SysAll.POS_END;
 // Exports
 File.Error = OSError;
 File.DirectoryIterator = DirectoryIterator;
 this.OS = {};
 this.OS.File = File;
 this.OS.Constants = SharedAll.Constants;
 this.OS.Shared = {
   LOG: SharedAll.LOG,
   Type: SysAll.Type,
   get DEBUG() {
     return SharedAll.Config.DEBUG;
   },
   set DEBUG(x) {
     return SharedAll.Config.DEBUG = x;
   }
 };
 Object.freeze(this.OS.Shared);
 this.OS.Path = Path;
 // Returns a resolved promise when all the queued operation have been completed.
 Object.defineProperty(OS.File, "queue", {
   get: function() {
     return Scheduler.queue;
   }
 });
 // Auto-flush OS.File during profile-before-change. This ensures that any I/O
 // that has been queued *before* profile-before-change is properly completed.
 // To ensure that I/O queued *during* profile-before-change is completed,
 // clients should register using AsyncShutdown.addBlocker.
 AsyncShutdown.profileBeforeChange.addBlocker(
   "OS.File: flush I/O queued before profile-before-change",
   // Wait until the latest currently enqueued promise is satisfied/rejected
   function() {
     let DEBUG = false;
     try {
       DEBUG = Services.prefs.getBoolPref("toolkit.osfile.debug.failshutdown");
     } catch (ex) {
       // Ignore
     }
     if (DEBUG) {
       // Return a promise that will never be satisfied
       return Promise.defer().promise;
     } else {
       return Scheduler.queue;
     }
   },
   function getDetails() {
     let result = {
       launched: Scheduler.launched,
       shutdown: Scheduler.shutdown,
       worker: !!Scheduler._worker,
       pendingReset: !!Scheduler.resetTimer,
       latestSent: Scheduler.Debugging.latestSent,
       latestReceived: Scheduler.Debugging.latestReceived,
       messagesSent: Scheduler.Debugging.messagesSent,
       messagesReceived: Scheduler.Debugging.messagesReceived,
       messagesQueued: Scheduler.Debugging.messagesQueued,
       DEBUG: SharedAll.Config.DEBUG
     };
     // Convert dates to strings for better readability
     for (let key of ["latestSent", "latestReceived"]) {
       if (result[key] && typeof result[key][0] == "number") {
         result[key][0] = Date(result[key][0]);
       }
     }
     return result;
   }
 );

The Tor Browser / annotate

toolkit/components/osfile/modules/osfile_async_front.jsm@129ffea94266 (annotated)

toolkit/components/osfile/modules/osfile_async_front.jsm