The Tor Browser: content/media/webaudio/blink/HRTFDatabaseLoader.cpp@97036ab72558 (annotated)

content/media/webaudio/blink/HRTFDatabaseLoader.cpp@97036ab72558 (annotated)

content/media/webaudio/blink/HRTFDatabaseLoader.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * 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, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  *     its contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 APPLE OR ITS CONTRIBUTORS 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.
  */
 #include "HRTFDatabaseLoader.h"
 #include "HRTFDatabase.h"
 using namespace mozilla;
 namespace WebCore {
 // Singleton
 nsTHashtable<HRTFDatabaseLoader::LoaderByRateEntry>*
     HRTFDatabaseLoader::s_loaderMap = nullptr;
 TemporaryRef<HRTFDatabaseLoader> HRTFDatabaseLoader::createAndLoadAsynchronouslyIfNecessary(float sampleRate)
 {
     MOZ_ASSERT(NS_IsMainThread());
     RefPtr<HRTFDatabaseLoader> loader;
     if (!s_loaderMap) {
         s_loaderMap = new nsTHashtable<LoaderByRateEntry>();
     }
     LoaderByRateEntry* entry = s_loaderMap->PutEntry(sampleRate);
     loader = entry->mLoader;
     if (loader) { // existing entry
         MOZ_ASSERT(sampleRate == loader->databaseSampleRate());
         return loader;
     }
     loader = new HRTFDatabaseLoader(sampleRate);
     entry->mLoader = loader;
     loader->loadAsynchronously();
     return loader;
 }
 HRTFDatabaseLoader::HRTFDatabaseLoader(float sampleRate)
     : m_refCnt(0)
     , m_threadLock("HRTFDatabaseLoader")
     , m_databaseLoaderThread(nullptr)
     , m_databaseSampleRate(sampleRate)
 {
     MOZ_ASSERT(NS_IsMainThread());
 }
 HRTFDatabaseLoader::~HRTFDatabaseLoader()
 {
     MOZ_ASSERT(NS_IsMainThread());
     waitForLoaderThreadCompletion();
     m_hrtfDatabase.reset();
     if (s_loaderMap) {
         // Remove ourself from the map.
         s_loaderMap->RemoveEntry(m_databaseSampleRate);
         if (s_loaderMap->Count() == 0) {
             delete s_loaderMap;
             s_loaderMap = nullptr;
         }
     }
 }
 size_t HRTFDatabaseLoader::sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 {
     size_t amount = aMallocSizeOf(this);
     // NB: Need to make sure we're not competing with the loader thread.
     const_cast<HRTFDatabaseLoader*>(this)->waitForLoaderThreadCompletion();
     if (m_hrtfDatabase) {
         amount += m_hrtfDatabase->sizeOfIncludingThis(aMallocSizeOf);
     }
     return amount;
 }
 class HRTFDatabaseLoader::ProxyReleaseEvent MOZ_FINAL : public nsRunnable {
 public:
     explicit ProxyReleaseEvent(HRTFDatabaseLoader* loader) : mLoader(loader) {}
     NS_IMETHOD Run() MOZ_OVERRIDE
     {
         mLoader->MainThreadRelease();
         return NS_OK;
     }
 private:
     HRTFDatabaseLoader* mLoader;
 };
 void HRTFDatabaseLoader::ProxyRelease()
 {
     nsCOMPtr<nsIThread> mainThread = do_GetMainThread();
     if (MOZ_LIKELY(mainThread)) {
         nsRefPtr<ProxyReleaseEvent> event = new ProxyReleaseEvent(this);
         DebugOnly<nsresult> rv =
             mainThread->Dispatch(event, NS_DISPATCH_NORMAL);
         MOZ_ASSERT(NS_SUCCEEDED(rv), "Failed to dispatch release event");
     } else {
         // Should be in XPCOM shutdown.
         MOZ_ASSERT(NS_IsMainThread(),
                    "Main thread is not available for dispatch.");
         MainThreadRelease();
     }
 }
 void HRTFDatabaseLoader::MainThreadRelease()
 {
     MOZ_ASSERT(NS_IsMainThread());
     int count = --m_refCnt;
     MOZ_ASSERT(count >= 0, "extra release");
     NS_LOG_RELEASE(this, count, "HRTFDatabaseLoader");
     if (count == 0) {
         // It is safe to delete here as the first reference can only be added
         // on this (main) thread.
         delete this;
     }
 }
 // Asynchronously load the database in this thread.
 static void databaseLoaderEntry(void* threadData)
 {
     PR_SetCurrentThreadName("HRTFDatabaseLdr");
     HRTFDatabaseLoader* loader = reinterpret_cast<HRTFDatabaseLoader*>(threadData);
     MOZ_ASSERT(loader);
     loader->load();
 }
 void HRTFDatabaseLoader::load()
 {
     MOZ_ASSERT(!NS_IsMainThread());
     MOZ_ASSERT(!m_hrtfDatabase.get(), "Called twice");
     // Load the default HRTF database.
     m_hrtfDatabase = HRTFDatabase::create(m_databaseSampleRate);
     // Notifies the main thread of completion.  See loadAsynchronously().
     Release();
 }
 void HRTFDatabaseLoader::loadAsynchronously()
 {
     MOZ_ASSERT(NS_IsMainThread());
     MOZ_ASSERT(m_refCnt, "Must not be called before a reference is added");
     // Add a reference so that the destructor won't run and wait for the
     // loader thread, until load() has completed.
     AddRef();
     MutexAutoLock locker(m_threadLock);
     MOZ_ASSERT(!m_hrtfDatabase.get() && !m_databaseLoaderThread,
                "Called twice");
     // Start the asynchronous database loading process.
     m_databaseLoaderThread =
         PR_CreateThread(PR_USER_THREAD, databaseLoaderEntry, this,
                         PR_PRIORITY_NORMAL, PR_GLOBAL_THREAD,
                         PR_JOINABLE_THREAD, 0);
 }
 bool HRTFDatabaseLoader::isLoaded() const
 {
     return m_hrtfDatabase.get();
 }
 void HRTFDatabaseLoader::waitForLoaderThreadCompletion()
 {
     MutexAutoLock locker(m_threadLock);
     // waitForThreadCompletion() should not be called twice for the same thread.
     if (m_databaseLoaderThread) {
         DebugOnly<PRStatus> status = PR_JoinThread(m_databaseLoaderThread);
         MOZ_ASSERT(status == PR_SUCCESS, "PR_JoinThread failed");
     }
     m_databaseLoaderThread = nullptr;
 }
 PLDHashOperator
 HRTFDatabaseLoader::shutdownEnumFunc(LoaderByRateEntry *entry, void* unused)
 {
     // Ensure the loader thread's reference is removed for leak analysis.
     entry->mLoader->waitForLoaderThreadCompletion();
     return PLDHashOperator::PL_DHASH_NEXT;
 }
 void HRTFDatabaseLoader::shutdown()
 {
     MOZ_ASSERT(NS_IsMainThread());
     if (s_loaderMap) {
         // Set s_loaderMap to nullptr so that the hashtable is not modified on
         // reference release during enumeration.
         nsTHashtable<LoaderByRateEntry>* loaderMap = s_loaderMap;
         s_loaderMap = nullptr;
         loaderMap->EnumerateEntries(shutdownEnumFunc, nullptr);
         delete loaderMap;
     }
 }
 } // namespace WebCore

The Tor Browser / annotate

content/media/webaudio/blink/HRTFDatabaseLoader.cpp@97036ab72558 (annotated)

content/media/webaudio/blink/HRTFDatabaseLoader.cpp