1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/MediaShutdownManager.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,149 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim:set ts=2 sw=2 sts=2 et cindent: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#include "MediaShutdownManager.h"
1.11 +#include "nsContentUtils.h"
1.12 +#include "mozilla/StaticPtr.h"
1.13 +#include "MediaDecoder.h"
1.14 +#include "SharedThreadPool.h"
1.15 +#include "prlog.h"
1.16 +
1.17 +namespace mozilla {
1.18 +
1.19 +#ifdef PR_LOGGING
1.20 +extern PRLogModuleInfo* gMediaDecoderLog;
1.21 +#define DECODER_LOG(type, msg) PR_LOG(gMediaDecoderLog, type, msg)
1.22 +#else
1.23 +#define DECODER_LOG(type, msg)
1.24 +#endif
1.25 +
1.26 +NS_IMPL_ISUPPORTS(MediaShutdownManager, nsIObserver)
1.27 +
1.28 +MediaShutdownManager::MediaShutdownManager()
1.29 + : mIsObservingShutdown(false),
1.30 + mIsDoingXPCOMShutDown(false)
1.31 +{
1.32 + MOZ_ASSERT(NS_IsMainThread());
1.33 + MOZ_COUNT_CTOR(MediaShutdownManager);
1.34 +}
1.35 +
1.36 +MediaShutdownManager::~MediaShutdownManager()
1.37 +{
1.38 + MOZ_ASSERT(NS_IsMainThread());
1.39 + MOZ_COUNT_DTOR(MediaShutdownManager);
1.40 +}
1.41 +
1.42 +// Note that we don't use ClearOnShutdown() on this StaticRefPtr, as that
1.43 +// may interfere with our shutdown listener.
1.44 +StaticRefPtr<MediaShutdownManager> MediaShutdownManager::sInstance;
1.45 +
1.46 +MediaShutdownManager&
1.47 +MediaShutdownManager::Instance()
1.48 +{
1.49 + MOZ_ASSERT(NS_IsMainThread());
1.50 + if (!sInstance) {
1.51 + sInstance = new MediaShutdownManager();
1.52 + }
1.53 + return *sInstance;
1.54 +}
1.55 +
1.56 +void
1.57 +MediaShutdownManager::EnsureCorrectShutdownObserverState()
1.58 +{
1.59 + MOZ_ASSERT(!mIsDoingXPCOMShutDown);
1.60 + bool needShutdownObserver = mDecoders.Count() > 0;
1.61 + if (needShutdownObserver != mIsObservingShutdown) {
1.62 + mIsObservingShutdown = needShutdownObserver;
1.63 + if (mIsObservingShutdown) {
1.64 + nsContentUtils::RegisterShutdownObserver(this);
1.65 + } else {
1.66 + nsContentUtils::UnregisterShutdownObserver(this);
1.67 + // Clear our singleton reference. This will probably delete
1.68 + // this instance, so don't deref |this| clearing sInstance.
1.69 + sInstance = nullptr;
1.70 + }
1.71 + }
1.72 +}
1.73 +
1.74 +void
1.75 +MediaShutdownManager::Register(MediaDecoder* aDecoder)
1.76 +{
1.77 + MOZ_ASSERT(NS_IsMainThread());
1.78 + // Don't call Register() after you've Unregistered() all the decoders,
1.79 + // that's not going to work.
1.80 + MOZ_ASSERT(!mDecoders.Contains(aDecoder));
1.81 + mDecoders.PutEntry(aDecoder);
1.82 + MOZ_ASSERT(mDecoders.Contains(aDecoder));
1.83 + MOZ_ASSERT(mDecoders.Count() > 0);
1.84 + EnsureCorrectShutdownObserverState();
1.85 +}
1.86 +
1.87 +void
1.88 +MediaShutdownManager::Unregister(MediaDecoder* aDecoder)
1.89 +{
1.90 + MOZ_ASSERT(NS_IsMainThread());
1.91 + MOZ_ASSERT(mDecoders.Contains(aDecoder));
1.92 + if (!mIsDoingXPCOMShutDown) {
1.93 + mDecoders.RemoveEntry(aDecoder);
1.94 + EnsureCorrectShutdownObserverState();
1.95 + }
1.96 +}
1.97 +
1.98 +NS_IMETHODIMP
1.99 +MediaShutdownManager::Observe(nsISupports *aSubjet,
1.100 + const char *aTopic,
1.101 + const char16_t *someData)
1.102 +{
1.103 + MOZ_ASSERT(NS_IsMainThread());
1.104 + if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
1.105 + Shutdown();
1.106 + }
1.107 + return NS_OK;
1.108 +}
1.109 +
1.110 +static PLDHashOperator
1.111 +ShutdownMediaDecoder(nsRefPtrHashKey<MediaDecoder>* aEntry, void*)
1.112 +{
1.113 + aEntry->GetKey()->Shutdown();
1.114 + return PL_DHASH_REMOVE;
1.115 +}
1.116 +
1.117 +void
1.118 +MediaShutdownManager::Shutdown()
1.119 +{
1.120 + MOZ_ASSERT(NS_IsMainThread());
1.121 + MOZ_ASSERT(sInstance);
1.122 +
1.123 + DECODER_LOG(PR_LOG_DEBUG, ("MediaShutdownManager::Shutdown() start..."));
1.124 +
1.125 + // Mark that we're shutting down, so that Unregister(*) calls don't remove
1.126 + // hashtable entries. If Unregsiter(*) was to remove from the hash table,
1.127 + // the iterations over the hashtables below would be disrupted.
1.128 + mIsDoingXPCOMShutDown = true;
1.129 +
1.130 + // Iterate over the decoders and shut them down, and remove them from the
1.131 + // hashtable.
1.132 + mDecoders.EnumerateEntries(ShutdownMediaDecoder, nullptr);
1.133 +
1.134 + // Ensure all media shared thread pools are shutdown. This joins with all
1.135 + // threads in the state machine thread pool, the decoder thread pool, and
1.136 + // any others.
1.137 + SharedThreadPool::SpinUntilShutdown();
1.138 +
1.139 + // Remove the MediaShutdownManager instance from the shutdown observer
1.140 + // list.
1.141 + nsContentUtils::UnregisterShutdownObserver(this);
1.142 +
1.143 + // Clear the singleton instance. The only remaining reference should be the
1.144 + // reference that the observer service used to call us with. The
1.145 + // MediaShutdownManager will be deleted once the observer service cleans
1.146 + // up after it finishes its notifications.
1.147 + sInstance = nullptr;
1.148 +
1.149 + DECODER_LOG(PR_LOG_DEBUG, ("MediaShutdownManager::Shutdown() end."));
1.150 +}
1.151 +
1.152 +} // namespace mozilla
