[worklets] Add AudioWorkletGlobalScope and AudioWorkletThread

third_party/WebKit/Source/modules/webaudio/AudioWorkletThread.cpp

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "modules/webaudio/AudioWorkletThread.h"
+
+#include "core/workers/WorkerBackingThread.h"
+#include "core/workers/WorkerThreadStartupData.h"
+#include "core/workers/WorkletBackingThreadHolder.h"
+#include "modules/webaudio/AudioWorkletGlobalScope.h"
+#include "platform/CrossThreadFunctional.h"
+#include "platform/WaitableEvent.h"
+#include "platform/WebThreadSupportingGC.h"
+#include "platform/tracing/TraceEvent.h"
+#include "platform/weborigin/SecurityOrigin.h"
+#include "public/platform/Platform.h"
+#include "wtf/Assertions.h"
+#include "wtf/PtrUtil.h"
+#include <memory>
+
+namespace blink {
+
+namespace {
+
+// TODO(hongchan): consider refactoring static methods in this class into
+// a template class.
+class AudioWorkletThreadHolder final : public WorkletBackingThreadHolder {
+ public:
+  static AudioWorkletThreadHolder* instance() {
+    MutexLocker locker(holderInstanceMutex());
+    return s_instance;
+  }
+
+  static void ensureInstance() {
+    if (!s_instance)
+      s_instance = new AudioWorkletThreadHolder;
+  }
+
+  static void clear() {
+    MutexLocker locker(holderInstanceMutex());
+    if (s_instance) {
+      s_instance->shutdownAndWait();
+      delete s_instance;
+      s_instance = nullptr;
+    }
+  }
+
+  static void createForTest() {
+    MutexLocker locker(holderInstanceMutex());
+    DCHECK_EQ(nullptr, s_instance);
+    s_instance =
+        new AudioWorkletThreadHolder(WorkerBackingThread::createForTest(
+            "AudioWorkletThread", BlinkGC::PerThreadHeapMode));
+  }
+
+ private:
+  AudioWorkletThreadHolder(
+      std::unique_ptr<WorkerBackingThread> backingThread = nullptr)
+      : WorkletBackingThreadHolder(
+            backingThread
+                ? std::move(backingThread)
+                : WorkerBackingThread::create("AudioWorkletThread",
+                                              BlinkGC::PerThreadHeapMode)) {}
+
+  static Mutex& holderInstanceMutex() {
+    DEFINE_THREAD_SAFE_STATIC_LOCAL(Mutex, holderMutex, new Mutex);
+    return holderMutex;
+  }
+
+  void initializeOnThread() {
+    MutexLocker locker(holderInstanceMutex());
+    DCHECK(!m_initialized);
+    m_thread->initialize();
+    m_initialized = true;
+  }
+
+  static AudioWorkletThreadHolder* s_instance;
+};
+
+AudioWorkletThreadHolder* AudioWorkletThreadHolder::s_instance = nullptr;
+
+}  // namespace
+
+std::unique_ptr<AudioWorkletThread> AudioWorkletThread::create(
+    PassRefPtr<WorkerLoaderProxy> workerLoaderProxy,
+    WorkerReportingProxy& workerReportingProxy) {
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("audio-worklet"),
+               "AudioWorkletThread::create");
+  DCHECK(isMainThread());
+  return wrapUnique(new AudioWorkletThread(std::move(workerLoaderProxy),
+                                           workerReportingProxy));
+}
+
+AudioWorkletThread::AudioWorkletThread(
+    PassRefPtr<WorkerLoaderProxy> workerLoaderProxy,
+    WorkerReportingProxy& workerReportingProxy)
+    : WorkerThread(std::move(workerLoaderProxy), workerReportingProxy) {}
+
+AudioWorkletThread::~AudioWorkletThread() {}
+
+WorkerBackingThread& AudioWorkletThread::workerBackingThread() {
+  return *AudioWorkletThreadHolder::instance()->thread();
+}
+
+void collectAllGarbageOnAudioWorkletThread(WaitableEvent* doneEvent) {
+  blink::ThreadState::current()->collectAllGarbage();
+  doneEvent->signal();
+}
+
+void AudioWorkletThread::collectAllGarbage() {
+  DCHECK(isMainThread());
+  WaitableEvent doneEvent;
+  AudioWorkletThreadHolder* instance = AudioWorkletThreadHolder::instance();
+  if (!instance)
+    return;
+  instance->thread()->backingThread().postTask(
+      BLINK_FROM_HERE, crossThreadBind(&collectAllGarbageOnAudioWorkletThread,
+                                       crossThreadUnretained(&doneEvent)));
+  doneEvent.wait();
+}
+
+void AudioWorkletThread::ensureSharedBackingThread() {
+  DCHECK(isMainThread());
+  AudioWorkletThreadHolder::ensureInstance();
+}
+
+void AudioWorkletThread::clearSharedBackingThread() {
+  DCHECK(isMainThread());
+  AudioWorkletThreadHolder::clear();
+}
+
+void AudioWorkletThread::createSharedBackingThreadForTest() {
+  AudioWorkletThreadHolder::createForTest();
+}
+
+WorkerOrWorkletGlobalScope* AudioWorkletThread::createWorkerGlobalScope(
+    std::unique_ptr<WorkerThreadStartupData> startupData) {
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("audio-worklet"),
+               "AudioWorkletThread::createWorkerGlobalScope");
+
+  RefPtr<SecurityOrigin> securityOrigin =
+      SecurityOrigin::create(startupData->m_scriptURL);
+  if (startupData->m_starterOriginPrivilegeData) {
+    securityOrigin->transferPrivilegesFrom(
+        std::move(startupData->m_starterOriginPrivilegeData));
+  }
+
+  return AudioWorkletGlobalScope::create(
+      startupData->m_scriptURL, startupData->m_userAgent,
+      securityOrigin.release(), this->isolate(), this);
+}
+
+}  // namespace blink