1 files changed, 223 insertions, 0 deletions
diff --git a/dom/media/webaudio/blink/HRTFDatabaseLoader.cpp b/dom/media/webaudio/blink/HRTFDatabaseLoader.cpp
new file mode 100644
index 000000000..090e1b217
--- /dev/null
+++ b/dom/media/webaudio/blink/HRTFDatabaseLoader.cpp
@@ -0,0 +1,223 @@
+/*
+ * 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;
+
+size_t HRTFDatabaseLoader::sizeOfLoaders(mozilla::MallocSizeOf aMallocSizeOf)
+{
+    return s_loaderMap ? s_loaderMap->SizeOfIncludingThis(aMallocSizeOf) : 0;
+}
+
+already_AddRefed<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.forget();
+    }
+
+    loader = new HRTFDatabaseLoader(sampleRate);
+    entry->mLoader = loader;
+
+    loader->loadAsynchronously();
+
+    return loader.forget();
+}
+
+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 final : public Runnable {
+public:
+    explicit ProxyReleaseEvent(HRTFDatabaseLoader* loader) : mLoader(loader) {}
+    NS_IMETHOD Run() override
+    {
+        mLoader->MainThreadRelease();
+        return NS_OK;
+    }
+private:
+    HRTFDatabaseLoader* mLoader;
+};
+
+void HRTFDatabaseLoader::ProxyRelease()
+{
+    nsCOMPtr<nsIThread> mainThread = do_GetMainThread();
+    if (MOZ_LIKELY(mainThread)) {
+        RefPtr<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;
+}
+
+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;
+        for (auto iter = loaderMap->Iter(); !iter.Done(); iter.Next()) {
+          iter.Get()->mLoader->waitForLoaderThreadCompletion();
+        }
+        delete loaderMap;
+    }
+}
+
+} // namespace WebCore