1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/webaudio/blink/HRTFDatabaseLoader.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,142 @@
1.4 +/*
1.5 + * Copyright (C) 2010 Google Inc. All rights reserved.
1.6 + *
1.7 + * Redistribution and use in source and binary forms, with or without
1.8 + * modification, are permitted provided that the following conditions
1.9 + * are met:
1.10 + *
1.11 + * 1. Redistributions of source code must retain the above copyright
1.12 + * notice, this list of conditions and the following disclaimer.
1.13 + * 2. Redistributions in binary form must reproduce the above copyright
1.14 + * notice, this list of conditions and the following disclaimer in the
1.15 + * documentation and/or other materials provided with the distribution.
1.16 + * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
1.17 + * its contributors may be used to endorse or promote products derived
1.18 + * from this software without specific prior written permission.
1.19 + *
1.20 + * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
1.21 + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
1.22 + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
1.23 + * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
1.24 + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
1.25 + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
1.26 + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
1.27 + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.28 + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1.29 + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.30 + */
1.31 +
1.32 +#ifndef HRTFDatabaseLoader_h
1.33 +#define HRTFDatabaseLoader_h
1.34 +
1.35 +#include "nsHashKeys.h"
1.36 +#include "mozilla/RefPtr.h"
1.37 +#include "mozilla/MemoryReporting.h"
1.38 +#include "mozilla/Mutex.h"
1.39 +#include "HRTFDatabase.h"
1.40 +
1.41 +template <class EntryType> class nsTHashtable;
1.42 +template <class T> class nsAutoRef;
1.43 +
1.44 +namespace WebCore {
1.45 +
1.46 +// HRTFDatabaseLoader will asynchronously load the default HRTFDatabase in a new thread.
1.47 +
1.48 +class HRTFDatabaseLoader {
1.49 +public:
1.50 + // Lazily creates a HRTFDatabaseLoader (if not already created) for the given sample-rate
1.51 + // and starts loading asynchronously (when created the first time).
1.52 + // Returns the HRTFDatabaseLoader.
1.53 + // Must be called from the main thread.
1.54 + static mozilla::TemporaryRef<HRTFDatabaseLoader> createAndLoadAsynchronouslyIfNecessary(float sampleRate);
1.55 +
1.56 + // AddRef and Release may be called from any thread.
1.57 + void AddRef()
1.58 + {
1.59 +#if defined(DEBUG) || defined(NS_BUILD_REFCNT_LOGGING)
1.60 + int count =
1.61 +#endif
1.62 + ++m_refCnt;
1.63 + MOZ_ASSERT(count > 0, "invalid ref count");
1.64 + NS_LOG_ADDREF(this, count, "HRTFDatabaseLoader", sizeof(*this));
1.65 + }
1.66 +
1.67 + void Release()
1.68 + {
1.69 + // The last reference can't be removed on a non-main thread because
1.70 + // the object can be accessed on the main thread from the hash
1.71 + // table via createAndLoadAsynchronouslyIfNecessary().
1.72 + int count = m_refCnt;
1.73 + MOZ_ASSERT(count > 0, "extra release");
1.74 + // Optimization attempt to possibly skip proxying the release to the
1.75 + // main thread.
1.76 + if (count != 1 && m_refCnt.compareExchange(count, count - 1)) {
1.77 + NS_LOG_RELEASE(this, count - 1, "HRTFDatabaseLoader");
1.78 + return;
1.79 + }
1.80 +
1.81 + ProxyRelease();
1.82 + }
1.83 +
1.84 + // Returns true once the default database has been completely loaded.
1.85 + bool isLoaded() const;
1.86 +
1.87 + // waitForLoaderThreadCompletion() may be called more than once,
1.88 + // on any thread except m_databaseLoaderThread.
1.89 + void waitForLoaderThreadCompletion();
1.90 +
1.91 + HRTFDatabase* database() { return m_hrtfDatabase.get(); }
1.92 +
1.93 + float databaseSampleRate() const { return m_databaseSampleRate; }
1.94 +
1.95 + static void shutdown();
1.96 +
1.97 + // Called in asynchronous loading thread.
1.98 + void load();
1.99 +
1.100 + size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
1.101 +
1.102 +private:
1.103 + // Both constructor and destructor must be called from the main thread.
1.104 + explicit HRTFDatabaseLoader(float sampleRate);
1.105 + ~HRTFDatabaseLoader();
1.106 +
1.107 + void ProxyRelease(); // any thread
1.108 + void MainThreadRelease(); // main thread only
1.109 + class ProxyReleaseEvent;
1.110 +
1.111 + // If it hasn't already been loaded, creates a new thread and initiates asynchronous loading of the default database.
1.112 + // This must be called from the main thread.
1.113 + void loadAsynchronously();
1.114 +
1.115 + // Map from sample-rate to loader.
1.116 + class LoaderByRateEntry : public nsFloatHashKey {
1.117 + public:
1.118 + LoaderByRateEntry(KeyTypePointer aKey)
1.119 + : nsFloatHashKey(aKey)
1.120 + , mLoader() // so PutEntry() will zero-initialize
1.121 + {
1.122 + }
1.123 + HRTFDatabaseLoader* mLoader;
1.124 + };
1.125 +
1.126 + static PLDHashOperator shutdownEnumFunc(LoaderByRateEntry *entry,
1.127 + void* unused);
1.128 +
1.129 + // Keeps track of loaders on a per-sample-rate basis.
1.130 + static nsTHashtable<LoaderByRateEntry> *s_loaderMap; // singleton
1.131 +
1.132 + mozilla::Atomic<int> m_refCnt;
1.133 +
1.134 + nsAutoRef<HRTFDatabase> m_hrtfDatabase;
1.135 +
1.136 + // Holding a m_threadLock is required when accessing m_databaseLoaderThread.
1.137 + mozilla::Mutex m_threadLock;
1.138 + PRThread* m_databaseLoaderThread;
1.139 +
1.140 + float m_databaseSampleRate;
1.141 +};
1.142 +
1.143 +} // namespace WebCore
1.144 +
1.145 +#endif // HRTFDatabaseLoader_h
