diff options
Diffstat (limited to 'widget/windows/AudioSession.cpp')
| -rw-r--r-- | widget/windows/AudioSession.cpp | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/widget/windows/AudioSession.cpp b/widget/windows/AudioSession.cpp new file mode 100644 index 0000000000..a38e2a83f6 --- /dev/null +++ b/widget/windows/AudioSession.cpp @@ -0,0 +1,351 @@ +/* -*- 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. + const IID IID_IAudioSessionControl = __uuidof(IAudioSessionControl); + auto agileAsc = MakeUnique<mozilla::mscom::AgileReference>( + IID_IAudioSessionControl, mAudioSessionControl); + mAudioSessionControl = nullptr; + NS_DispatchToMainThread(NS_NewRunnableFunction( + "FreeAudioSession", [agileAsc = std::move(agileAsc), + IID_IAudioSessionControl, shouldRestart] { + RefPtr<IAudioSessionControl> toDelete; + [[maybe_unused]] HRESULT hr = agileAsc->Resolve( + IID_IAudioSessionControl, getter_AddRefs(toDelete)); + MOZ_ASSERT(SUCCEEDED(hr)); + // Now release the AgileReference which holds our only reference to the + // IAudioSessionControl, then maybe restart. + 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 |