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/*
* 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 already_AddRefed<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() {
if (!m_databaseLoaded) {
return nullptr;
}
return m_hrtfDatabase.get();
}
float databaseSampleRate() const { return m_databaseSampleRate; }
static void shutdown();
// Called in asynchronous loading thread.
void load();
// Sums the size of all cached database loaders.
static size_t sizeOfLoaders(mozilla::MallocSizeOf aMallocSizeOf);
private:
// Both constructor and destructor must be called from the main thread.
explicit HRTFDatabaseLoader(float sampleRate);
~HRTFDatabaseLoader();
size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
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:
explicit LoaderByRateEntry(KeyTypePointer aKey)
: nsFloatHashKey(aKey),
mLoader() // so PutEntry() will zero-initialize
{}
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
return mLoader ? mLoader->sizeOfIncludingThis(aMallocSizeOf) : 0;
}
// The HRTFDatabaseLoader removes itself from s_loaderMap on destruction.
HRTFDatabaseLoader* MOZ_NON_OWNING_REF mLoader;
};
// 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 MOZ_GUARDED_BY(m_threadLock);
float m_databaseSampleRate;
mozilla::Atomic<bool> m_databaseLoaded;
};
} // namespace WebCore
#endif // HRTFDatabaseLoader_h