/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim:set ts=2 sw=2 sts=2 et cindent: */

/* 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 "mozilla/Logging.h"

#include "mozilla/StaticPtr.h"

#include "mozilla/Services.h"

#include "MediaDecoder.h"

#include "MediaShutdownManager.h"

namespace mozilla {

#undef LOGW

extern LazyLogModule gMediaDecoderLog;

#define DECODER_LOG(type, msg) MOZ_LOG(gMediaDecoderLog, type, msg)

#define LOGW(...) NS_WARNING(nsPrintfCString(__VA_ARGS__).get())

NS_IMPL_ISUPPORTS(MediaShutdownManager, nsIAsyncShutdownBlocker)

MediaShutdownManager::MediaShutdownManager()

{

  MOZ_ASSERT(NS_IsMainThread());

  MOZ_DIAGNOSTIC_ASSERT(sInitPhase == NotInited);

}

MediaShutdownManager::~MediaShutdownManager()

{

  MOZ_ASSERT(NS_IsMainThread());

}

// Note that we don't use ClearOnShutdown() on this StaticRefPtr, as that

// may interfere with our shutdown listener.

StaticRefPtr<MediaShutdownManager> MediaShutdownManager::sInstance;

MediaShutdownManager::InitPhase MediaShutdownManager::sInitPhase = MediaShutdownManager::NotInited;

MediaShutdownManager&

MediaShutdownManager::Instance()

{

  MOZ_ASSERT(NS_IsMainThread());

#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED

  if (!sInstance) {

    MOZ_CRASH_UNSAFE_PRINTF("sInstance is null. sInitPhase=%d", int(sInitPhase));

  }

#endif

  return *sInstance;

}

static nsCOMPtr<nsIAsyncShutdownClient>

GetShutdownBarrier()

{

  nsCOMPtr<nsIAsyncShutdownService> svc = services::GetAsyncShutdown();

  MOZ_RELEASE_ASSERT(svc);

  nsCOMPtr<nsIAsyncShutdownClient> barrier;

  nsresult rv = svc->GetProfileBeforeChange(getter_AddRefs(barrier));

  if (!barrier) {

    // We are probably in a content process. We need to do cleanup at

    // XPCOM shutdown in leakchecking builds.

    rv = svc->GetXpcomWillShutdown(getter_AddRefs(barrier));

  }

  MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));

  MOZ_RELEASE_ASSERT(barrier);

  return barrier.forget();

}

void

MediaShutdownManager::InitStatics()

{

  MOZ_ASSERT(NS_IsMainThread());

  if (sInitPhase != NotInited) {

    return;

  }

  sInstance = new MediaShutdownManager();

  MOZ_DIAGNOSTIC_ASSERT(sInstance);

  nsresult rv = GetShutdownBarrier()->AddBlocker(

    sInstance, NS_LITERAL_STRING(__FILE__), __LINE__,

    NS_LITERAL_STRING("MediaShutdownManager shutdown"));

  if (NS_FAILED(rv)) {

    LOGW("Failed to add shutdown blocker! rv=%x", uint32_t(rv));

    sInitPhase = InitFailed;

    return;

  }

  sInitPhase = InitSucceeded;

}

void

MediaShutdownManager::RemoveBlocker()

{

  MOZ_ASSERT(NS_IsMainThread());

  MOZ_DIAGNOSTIC_ASSERT(sInitPhase == XPCOMShutdownStarted);

  MOZ_ASSERT(mDecoders.Count() == 0);

  GetShutdownBarrier()->RemoveBlocker(this);

  // Clear our singleton reference. This will probably delete

  // this instance, so don't deref |this| clearing sInstance.

  sInitPhase = XPCOMShutdownEnded;

  sInstance = nullptr;

  DECODER_LOG(LogLevel::Debug, ("MediaShutdownManager::BlockShutdown() end."));

}

nsresult

MediaShutdownManager::Register(MediaDecoder* aDecoder)

{

  MOZ_ASSERT(NS_IsMainThread());

  if (sInitPhase == InitFailed) {

    return NS_ERROR_NOT_INITIALIZED;

  }

  if (sInitPhase == XPCOMShutdownStarted) {

    return NS_ERROR_ABORT;

  }

  // Don't call Register() after you've Unregistered() all the decoders,

  // that's not going to work.

  MOZ_ASSERT(!mDecoders.Contains(aDecoder));

  mDecoders.PutEntry(aDecoder);

  MOZ_ASSERT(mDecoders.Contains(aDecoder));

  MOZ_ASSERT(mDecoders.Count() > 0);

  return NS_OK;

}

void

MediaShutdownManager::Unregister(MediaDecoder* aDecoder)

{

  MOZ_ASSERT(NS_IsMainThread());

  if (!mDecoders.Contains(aDecoder)) {

    return;

  }

  mDecoders.RemoveEntry(aDecoder);

  if (sInitPhase == XPCOMShutdownStarted && mDecoders.Count() == 0) {

    RemoveBlocker();

  }

}

NS_IMETHODIMP

MediaShutdownManager::GetName(nsAString& aName)

{

  aName = NS_LITERAL_STRING("MediaShutdownManager: shutdown");

  return NS_OK;

}

NS_IMETHODIMP

MediaShutdownManager::GetState(nsIPropertyBag**)

{

  return NS_OK;

}

NS_IMETHODIMP

MediaShutdownManager::BlockShutdown(nsIAsyncShutdownClient*)

{

  MOZ_ASSERT(NS_IsMainThread());

  MOZ_DIAGNOSTIC_ASSERT(sInitPhase == InitSucceeded);

  MOZ_DIAGNOSTIC_ASSERT(sInstance);

  DECODER_LOG(LogLevel::Debug, ("MediaShutdownManager::BlockShutdown() start..."));

  // Set this flag to ensure no Register() is allowed when Shutdown() begins.

  sInitPhase = XPCOMShutdownStarted;

  auto oldCount = mDecoders.Count();

  if (oldCount == 0) {

    RemoveBlocker();

    return NS_OK;

  }

  // Iterate over the decoders and shut them down.

  for (auto iter = mDecoders.Iter(); !iter.Done(); iter.Next()) {

    iter.Get()->GetKey()->NotifyXPCOMShutdown();

    // Check MediaDecoder::Shutdown doesn't call Unregister() synchronously in

    // order not to corrupt our hashtable traversal.

    MOZ_ASSERT(mDecoders.Count() == oldCount);

  }

  return NS_OK;

}

} // namespace mozilla

// avoid redefined macro in unified build

#undef LOGW