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-rw-r--r--widget/windows/AudioSession.cpp346
1 files changed, 346 insertions, 0 deletions
diff --git a/widget/windows/AudioSession.cpp b/widget/windows/AudioSession.cpp
new file mode 100644
index 0000000000..c14278f56c
--- /dev/null
+++ b/widget/windows/AudioSession.cpp
@@ -0,0 +1,346 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <atomic>
+#include <audiopolicy.h>
+#include <windows.h>
+#include <mmdeviceapi.h>
+
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPtr.h"
+#include "nsIStringBundle.h"
+
+#include "nsCOMPtr.h"
+#include "nsID.h"
+#include "nsServiceManagerUtils.h"
+#include "nsString.h"
+#include "nsThreadUtils.h"
+#include "nsXULAppAPI.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/mscom/AgileReference.h"
+#include "mozilla/mscom/Utils.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/WindowsVersion.h"
+
+namespace mozilla {
+namespace widget {
+
+/*
+ * To take advantage of what Vista+ have to offer with respect to audio,
+ * we need to maintain an audio session. This class wraps IAudioSessionControl
+ * and implements IAudioSessionEvents (for callbacks from Windows)
+ */
+class AudioSession final : public IAudioSessionEvents {
+ public:
+ AudioSession();
+
+ static AudioSession* GetSingleton();
+
+ // COM IUnknown
+ STDMETHODIMP_(ULONG) AddRef();
+ STDMETHODIMP QueryInterface(REFIID, void**);
+ STDMETHODIMP_(ULONG) Release();
+
+ // IAudioSessionEvents
+ STDMETHODIMP OnChannelVolumeChanged(DWORD aChannelCount,
+ float aChannelVolumeArray[],
+ DWORD aChangedChannel, LPCGUID aContext);
+ STDMETHODIMP OnDisplayNameChanged(LPCWSTR aDisplayName, LPCGUID aContext);
+ STDMETHODIMP OnGroupingParamChanged(LPCGUID aGroupingParam, LPCGUID aContext);
+ STDMETHODIMP OnIconPathChanged(LPCWSTR aIconPath, LPCGUID aContext);
+ STDMETHODIMP OnSessionDisconnected(AudioSessionDisconnectReason aReason);
+ STDMETHODIMP OnSimpleVolumeChanged(float aVolume, BOOL aMute,
+ LPCGUID aContext);
+ STDMETHODIMP OnStateChanged(AudioSessionState aState);
+
+ void Start();
+ void Stop(bool shouldRestart = false);
+
+ nsresult GetSessionData(nsID& aID, nsString& aSessionName,
+ nsString& aIconPath);
+ nsresult SetSessionData(const nsID& aID, const nsString& aSessionName,
+ const nsString& aIconPath);
+
+ private:
+ ~AudioSession() = default;
+
+ void StopInternal(const MutexAutoLock& aProofOfLock,
+ bool shouldRestart = false);
+
+ protected:
+ RefPtr<IAudioSessionControl> mAudioSessionControl;
+ nsString mDisplayName;
+ nsString mIconPath;
+ nsID mSessionGroupingParameter;
+ // Guards the IAudioSessionControl
+ mozilla::Mutex mMutex MOZ_UNANNOTATED;
+
+ ThreadSafeAutoRefCnt mRefCnt;
+ NS_DECL_OWNINGTHREAD
+};
+
+StaticRefPtr<AudioSession> sService;
+
+void StartAudioSession() {
+ MOZ_ASSERT(NS_IsMainThread());
+ MOZ_ASSERT(!sService);
+ sService = new AudioSession();
+
+ // Destroy AudioSession only after any background task threads have been
+ // stopped or abandoned.
+ ClearOnShutdown(&sService, ShutdownPhase::XPCOMShutdownFinal);
+
+ NS_DispatchBackgroundTask(
+ NS_NewCancelableRunnableFunction("StartAudioSession", []() -> void {
+ MOZ_ASSERT(AudioSession::GetSingleton(),
+ "AudioSession should outlive background threads");
+ AudioSession::GetSingleton()->Start();
+ }));
+}
+
+void StopAudioSession() {
+ MOZ_ASSERT(NS_IsMainThread());
+ MOZ_ASSERT(sService);
+ NS_DispatchBackgroundTask(
+ NS_NewRunnableFunction("StopAudioSession", []() -> void {
+ MOZ_ASSERT(AudioSession::GetSingleton(),
+ "AudioSession should outlive background threads");
+ AudioSession::GetSingleton()->Stop();
+ }));
+}
+
+AudioSession* AudioSession::GetSingleton() {
+ MOZ_ASSERT(mscom::IsCurrentThreadMTA());
+ return sService;
+}
+
+// It appears Windows will use us on a background thread ...
+NS_IMPL_ADDREF(AudioSession)
+NS_IMPL_RELEASE(AudioSession)
+
+STDMETHODIMP
+AudioSession::QueryInterface(REFIID iid, void** ppv) {
+ const IID IID_IAudioSessionEvents = __uuidof(IAudioSessionEvents);
+ if ((IID_IUnknown == iid) || (IID_IAudioSessionEvents == iid)) {
+ *ppv = static_cast<IAudioSessionEvents*>(this);
+ AddRef();
+ return S_OK;
+ }
+
+ return E_NOINTERFACE;
+}
+
+AudioSession::AudioSession() : mMutex("AudioSessionControl") {
+ // This func must be run on the main thread as
+ // nsStringBundle is not thread safe otherwise
+ MOZ_ASSERT(NS_IsMainThread());
+
+ MOZ_ASSERT(XRE_IsParentProcess(),
+ "Should only get here in a chrome process!");
+
+ nsCOMPtr<nsIStringBundleService> bundleService =
+ do_GetService(NS_STRINGBUNDLE_CONTRACTID);
+ MOZ_ASSERT(bundleService);
+
+ nsCOMPtr<nsIStringBundle> bundle;
+ bundleService->CreateBundle("chrome://branding/locale/brand.properties",
+ getter_AddRefs(bundle));
+ MOZ_ASSERT(bundle);
+ bundle->GetStringFromName("brandFullName", mDisplayName);
+
+ wchar_t* buffer;
+ mIconPath.GetMutableData(&buffer, MAX_PATH);
+ ::GetModuleFileNameW(nullptr, buffer, MAX_PATH);
+
+ [[maybe_unused]] nsresult rv =
+ nsID::GenerateUUIDInPlace(mSessionGroupingParameter);
+ MOZ_ASSERT(rv == NS_OK);
+}
+
+// Once we are started Windows will hold a reference to us through our
+// IAudioSessionEvents interface that will keep us alive until the appshell
+// calls Stop.
+void AudioSession::Start() {
+ MOZ_ASSERT(mscom::IsCurrentThreadMTA());
+
+ const CLSID CLSID_MMDeviceEnumerator = __uuidof(MMDeviceEnumerator);
+ const IID IID_IMMDeviceEnumerator = __uuidof(IMMDeviceEnumerator);
+ const IID IID_IAudioSessionManager = __uuidof(IAudioSessionManager);
+
+ MutexAutoLock lock(mMutex);
+ MOZ_ASSERT(!mAudioSessionControl);
+ MOZ_ASSERT(!mDisplayName.IsEmpty() || !mIconPath.IsEmpty(),
+ "Should never happen ...");
+
+ auto scopeExit = MakeScopeExit([&] { StopInternal(lock); });
+
+ RefPtr<IMMDeviceEnumerator> enumerator;
+ HRESULT hr =
+ ::CoCreateInstance(CLSID_MMDeviceEnumerator, nullptr, CLSCTX_ALL,
+ IID_IMMDeviceEnumerator, getter_AddRefs(enumerator));
+ if (FAILED(hr)) {
+ return;
+ }
+
+ RefPtr<IMMDevice> device;
+ hr = enumerator->GetDefaultAudioEndpoint(
+ EDataFlow::eRender, ERole::eMultimedia, getter_AddRefs(device));
+ if (FAILED(hr)) {
+ return;
+ }
+
+ RefPtr<IAudioSessionManager> manager;
+ hr = device->Activate(IID_IAudioSessionManager, CLSCTX_ALL, nullptr,
+ getter_AddRefs(manager));
+ if (FAILED(hr)) {
+ return;
+ }
+
+ hr = manager->GetAudioSessionControl(&GUID_NULL, 0,
+ getter_AddRefs(mAudioSessionControl));
+
+ if (FAILED(hr) || !mAudioSessionControl) {
+ return;
+ }
+
+ // Increments refcount of 'this'.
+ hr = mAudioSessionControl->RegisterAudioSessionNotification(this);
+ if (FAILED(hr)) {
+ return;
+ }
+
+ hr = mAudioSessionControl->SetGroupingParam(
+ (LPGUID) & (mSessionGroupingParameter), nullptr);
+ if (FAILED(hr)) {
+ return;
+ }
+
+ hr = mAudioSessionControl->SetDisplayName(mDisplayName.get(), nullptr);
+ if (FAILED(hr)) {
+ return;
+ }
+
+ hr = mAudioSessionControl->SetIconPath(mIconPath.get(), nullptr);
+ if (FAILED(hr)) {
+ return;
+ }
+
+ scopeExit.release();
+}
+
+void AudioSession::Stop(bool shouldRestart) {
+ MOZ_ASSERT(mscom::IsCurrentThreadMTA());
+
+ MutexAutoLock lock(mMutex);
+ StopInternal(lock, shouldRestart);
+}
+
+void AudioSession::StopInternal(const MutexAutoLock& aProofOfLock,
+ bool shouldRestart) {
+ if (!mAudioSessionControl) {
+ return;
+ }
+
+ // Decrement refcount of 'this'
+ mAudioSessionControl->UnregisterAudioSessionNotification(this);
+
+ // Deleting the IAudioSessionControl COM object requires the STA/main thread.
+ // Audio code may concurrently be running on the main thread and it may
+ // block waiting for this to complete, creating deadlock. So we destroy the
+ // IAudioSessionControl on the main thread instead. In order to do that, we
+ // need to marshall the object to the main thread's apartment with an
+ // AgileReference.
+ mscom::AgileReference agileAsc(mAudioSessionControl);
+ mAudioSessionControl = nullptr;
+ NS_DispatchToMainThread(NS_NewRunnableFunction(
+ "FreeAudioSession",
+ [agileAsc = std::move(agileAsc), shouldRestart]() mutable {
+ // Now release the AgileReference which holds our only reference to the
+ // IAudioSessionControl, then maybe restart.
+ agileAsc = nullptr;
+ if (shouldRestart) {
+ NS_DispatchBackgroundTask(
+ NS_NewCancelableRunnableFunction("RestartAudioSession", [] {
+ AudioSession* as = AudioSession::GetSingleton();
+ MOZ_ASSERT(as);
+ as->Start();
+ }));
+ }
+ }));
+}
+
+void CopynsID(nsID& lhs, const nsID& rhs) {
+ lhs.m0 = rhs.m0;
+ lhs.m1 = rhs.m1;
+ lhs.m2 = rhs.m2;
+ for (int i = 0; i < 8; i++) {
+ lhs.m3[i] = rhs.m3[i];
+ }
+}
+
+nsresult AudioSession::GetSessionData(nsID& aID, nsString& aSessionName,
+ nsString& aIconPath) {
+ CopynsID(aID, mSessionGroupingParameter);
+ aSessionName = mDisplayName;
+ aIconPath = mIconPath;
+
+ return NS_OK;
+}
+
+nsresult AudioSession::SetSessionData(const nsID& aID,
+ const nsString& aSessionName,
+ const nsString& aIconPath) {
+ MOZ_ASSERT(!XRE_IsParentProcess(),
+ "Should never get here in a chrome process!");
+ CopynsID(mSessionGroupingParameter, aID);
+ mDisplayName = aSessionName;
+ mIconPath = aIconPath;
+ return NS_OK;
+}
+
+STDMETHODIMP
+AudioSession::OnChannelVolumeChanged(DWORD aChannelCount,
+ float aChannelVolumeArray[],
+ DWORD aChangedChannel, LPCGUID aContext) {
+ return S_OK; // NOOP
+}
+
+STDMETHODIMP
+AudioSession::OnDisplayNameChanged(LPCWSTR aDisplayName, LPCGUID aContext) {
+ return S_OK; // NOOP
+}
+
+STDMETHODIMP
+AudioSession::OnGroupingParamChanged(LPCGUID aGroupingParam, LPCGUID aContext) {
+ return S_OK; // NOOP
+}
+
+STDMETHODIMP
+AudioSession::OnIconPathChanged(LPCWSTR aIconPath, LPCGUID aContext) {
+ return S_OK; // NOOP
+}
+
+STDMETHODIMP
+AudioSession::OnSessionDisconnected(AudioSessionDisconnectReason aReason) {
+ Stop(true /* shouldRestart */);
+ return S_OK;
+}
+
+STDMETHODIMP
+AudioSession::OnSimpleVolumeChanged(float aVolume, BOOL aMute,
+ LPCGUID aContext) {
+ return S_OK; // NOOP
+}
+
+STDMETHODIMP
+AudioSession::OnStateChanged(AudioSessionState aState) {
+ return S_OK; // NOOP
+}
+
+} // namespace widget
+} // namespace mozilla