michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim:set ts=2 sw=2 sts=2 et cindent: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "MediaShutdownManager.h"
michael@0: #include "nsContentUtils.h"
michael@0: #include "mozilla/StaticPtr.h"
michael@0: #include "MediaDecoder.h"
michael@0: #include "SharedThreadPool.h"
michael@0: #include "prlog.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: #ifdef PR_LOGGING
michael@0: extern PRLogModuleInfo* gMediaDecoderLog;
michael@0: #define DECODER_LOG(type, msg) PR_LOG(gMediaDecoderLog, type, msg)
michael@0: #else
michael@0: #define DECODER_LOG(type, msg)
michael@0: #endif
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(MediaShutdownManager, nsIObserver)
michael@0: 
michael@0: MediaShutdownManager::MediaShutdownManager()
michael@0:   : mIsObservingShutdown(false),
michael@0:     mIsDoingXPCOMShutDown(false)
michael@0: {
michael@0:   MOZ_ASSERT(NS_IsMainThread());
michael@0:   MOZ_COUNT_CTOR(MediaShutdownManager);
michael@0: }
michael@0: 
michael@0: MediaShutdownManager::~MediaShutdownManager()
michael@0: {
michael@0:   MOZ_ASSERT(NS_IsMainThread());
michael@0:   MOZ_COUNT_DTOR(MediaShutdownManager);
michael@0: }
michael@0: 
michael@0: // Note that we don't use ClearOnShutdown() on this StaticRefPtr, as that
michael@0: // may interfere with our shutdown listener.
michael@0: StaticRefPtr<MediaShutdownManager> MediaShutdownManager::sInstance;
michael@0: 
michael@0: MediaShutdownManager&
michael@0: MediaShutdownManager::Instance()
michael@0: {
michael@0:   MOZ_ASSERT(NS_IsMainThread());
michael@0:   if (!sInstance) {
michael@0:     sInstance = new MediaShutdownManager();
michael@0:   }
michael@0:   return *sInstance;
michael@0: }
michael@0: 
michael@0: void
michael@0: MediaShutdownManager::EnsureCorrectShutdownObserverState()
michael@0: {
michael@0:   MOZ_ASSERT(!mIsDoingXPCOMShutDown);
michael@0:   bool needShutdownObserver = mDecoders.Count() > 0;
michael@0:   if (needShutdownObserver != mIsObservingShutdown) {
michael@0:     mIsObservingShutdown = needShutdownObserver;
michael@0:     if (mIsObservingShutdown) {
michael@0:       nsContentUtils::RegisterShutdownObserver(this);
michael@0:     } else {
michael@0:       nsContentUtils::UnregisterShutdownObserver(this);
michael@0:       // Clear our singleton reference. This will probably delete
michael@0:       // this instance, so don't deref |this| clearing sInstance.
michael@0:       sInstance = nullptr;
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: MediaShutdownManager::Register(MediaDecoder* aDecoder)
michael@0: {
michael@0:   MOZ_ASSERT(NS_IsMainThread());
michael@0:   // Don't call Register() after you've Unregistered() all the decoders,
michael@0:   // that's not going to work.
michael@0:   MOZ_ASSERT(!mDecoders.Contains(aDecoder));
michael@0:   mDecoders.PutEntry(aDecoder);
michael@0:   MOZ_ASSERT(mDecoders.Contains(aDecoder));
michael@0:   MOZ_ASSERT(mDecoders.Count() > 0);
michael@0:   EnsureCorrectShutdownObserverState();
michael@0: }
michael@0: 
michael@0: void
michael@0: MediaShutdownManager::Unregister(MediaDecoder* aDecoder)
michael@0: {
michael@0:   MOZ_ASSERT(NS_IsMainThread());
michael@0:   MOZ_ASSERT(mDecoders.Contains(aDecoder));
michael@0:   if (!mIsDoingXPCOMShutDown) {
michael@0:     mDecoders.RemoveEntry(aDecoder);
michael@0:     EnsureCorrectShutdownObserverState();
michael@0:   }
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: MediaShutdownManager::Observe(nsISupports *aSubjet,
michael@0:                               const char *aTopic,
michael@0:                               const char16_t *someData)
michael@0: {
michael@0:   MOZ_ASSERT(NS_IsMainThread());
michael@0:   if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
michael@0:     Shutdown();
michael@0:   }
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: static PLDHashOperator
michael@0: ShutdownMediaDecoder(nsRefPtrHashKey<MediaDecoder>* aEntry, void*)
michael@0: {
michael@0:   aEntry->GetKey()->Shutdown();
michael@0:   return PL_DHASH_REMOVE;
michael@0: }
michael@0: 
michael@0: void
michael@0: MediaShutdownManager::Shutdown()
michael@0: {
michael@0:   MOZ_ASSERT(NS_IsMainThread());
michael@0:   MOZ_ASSERT(sInstance);
michael@0: 
michael@0:   DECODER_LOG(PR_LOG_DEBUG, ("MediaShutdownManager::Shutdown() start..."));
michael@0: 
michael@0:   // Mark that we're shutting down, so that Unregister(*) calls don't remove
michael@0:   // hashtable entries. If Unregsiter(*) was to remove from the hash table,
michael@0:   // the iterations over the hashtables below would be disrupted.
michael@0:   mIsDoingXPCOMShutDown = true;
michael@0: 
michael@0:   // Iterate over the decoders and shut them down, and remove them from the
michael@0:   // hashtable.
michael@0:   mDecoders.EnumerateEntries(ShutdownMediaDecoder, nullptr);
michael@0: 
michael@0:   // Ensure all media shared thread pools are shutdown. This joins with all
michael@0:   // threads in the state machine thread pool, the decoder thread pool, and
michael@0:   // any others.
michael@0:   SharedThreadPool::SpinUntilShutdown();
michael@0: 
michael@0:   // Remove the MediaShutdownManager instance from the shutdown observer
michael@0:   // list.
michael@0:   nsContentUtils::UnregisterShutdownObserver(this);
michael@0: 
michael@0:   // Clear the singleton instance. The only remaining reference should be the
michael@0:   // reference that the observer service used to call us with. The
michael@0:   // MediaShutdownManager will be deleted once the observer service cleans
michael@0:   // up after it finishes its notifications.
michael@0:   sInstance = nullptr;
michael@0: 
michael@0:   DECODER_LOG(PR_LOG_DEBUG, ("MediaShutdownManager::Shutdown() end."));
michael@0: }
michael@0: 
michael@0: } // namespace mozilla