The Tor Browser: content/media/webaudio/blink/HRTFDatabaseLoader.h@b8a032363ba2 (annotated)

content/media/webaudio/blink/HRTFDatabaseLoader.h@b8a032363ba2 (annotated)

content/media/webaudio/blink/HRTFDatabaseLoader.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
  * 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.
  */
 #ifndef HRTFDatabaseLoader_h
 #define HRTFDatabaseLoader_h
 #include "nsHashKeys.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/Mutex.h"
 #include "HRTFDatabase.h"
 template <class EntryType> class nsTHashtable;
 template <class T> class nsAutoRef;
 namespace WebCore {
 // HRTFDatabaseLoader will asynchronously load the default HRTFDatabase in a new thread.
 class HRTFDatabaseLoader {
 public:
     // Lazily creates a HRTFDatabaseLoader (if not already created) for the given sample-rate
     // and starts loading asynchronously (when created the first time).
     // Returns the HRTFDatabaseLoader.
     // Must be called from the main thread.
     static mozilla::TemporaryRef<HRTFDatabaseLoader> createAndLoadAsynchronouslyIfNecessary(float sampleRate);
     // AddRef and Release may be called from any thread.
     void AddRef()
     {
 #if defined(DEBUG) || defined(NS_BUILD_REFCNT_LOGGING)
         int count =
 #endif
           ++m_refCnt;
         MOZ_ASSERT(count > 0, "invalid ref count");
         NS_LOG_ADDREF(this, count, "HRTFDatabaseLoader", sizeof(*this));
     }
     void Release()
     {
         // The last reference can't be removed on a non-main thread because
         // the object can be accessed on the main thread from the hash
         // table via createAndLoadAsynchronouslyIfNecessary().
         int count = m_refCnt;
         MOZ_ASSERT(count > 0, "extra release");
         // Optimization attempt to possibly skip proxying the release to the
         // main thread.
         if (count != 1 && m_refCnt.compareExchange(count, count - 1)) {
             NS_LOG_RELEASE(this, count - 1, "HRTFDatabaseLoader");
             return;
         }
         ProxyRelease();
     }
     // Returns true once the default database has been completely loaded.
     bool isLoaded() const;
     // waitForLoaderThreadCompletion() may be called more than once,
     // on any thread except m_databaseLoaderThread.
     void waitForLoaderThreadCompletion();
     HRTFDatabase* database() { return m_hrtfDatabase.get(); }
     float databaseSampleRate() const { return m_databaseSampleRate; }
     static void shutdown();
     // Called in asynchronous loading thread.
     void load();
     size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
 private:
     // Both constructor and destructor must be called from the main thread.
     explicit HRTFDatabaseLoader(float sampleRate);
     ~HRTFDatabaseLoader();
     void ProxyRelease(); // any thread
     void MainThreadRelease(); // main thread only
     class ProxyReleaseEvent;
     // If it hasn't already been loaded, creates a new thread and initiates asynchronous loading of the default database.
     // This must be called from the main thread.
     void loadAsynchronously();
     // Map from sample-rate to loader.
     class LoaderByRateEntry : public nsFloatHashKey {
     public:
         LoaderByRateEntry(KeyTypePointer aKey)
             : nsFloatHashKey(aKey)
             , mLoader() // so PutEntry() will zero-initialize
         {
         }
         HRTFDatabaseLoader* mLoader;
     };
     static PLDHashOperator shutdownEnumFunc(LoaderByRateEntry *entry,
                                             void* unused);
     // Keeps track of loaders on a per-sample-rate basis.
     static nsTHashtable<LoaderByRateEntry> *s_loaderMap; // singleton
     mozilla::Atomic<int> m_refCnt;
     nsAutoRef<HRTFDatabase> m_hrtfDatabase;
     // Holding a m_threadLock is required when accessing m_databaseLoaderThread.
     mozilla::Mutex m_threadLock;
     PRThread* m_databaseLoaderThread;
     float m_databaseSampleRate;
 };
 } // namespace WebCore
 #endif // HRTFDatabaseLoader_h

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content/media/webaudio/blink/HRTFDatabaseLoader.h@b8a032363ba2 (annotated)

content/media/webaudio/blink/HRTFDatabaseLoader.h