/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* 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 "VsyncParent.h"

#include "BackgroundParent.h"

#include "BackgroundParentImpl.h"

#include "gfxPlatform.h"

#include "mozilla/Unused.h"

#include "nsIThread.h"

#include "nsThreadUtils.h"

#include "VsyncSource.h"

namespace mozilla {

using namespace ipc;

namespace layout {

/*static*/ already_AddRefed<VsyncParent>

VsyncParent::Create()

{

  AssertIsOnBackgroundThread();

  RefPtr<gfx::VsyncSource> vsyncSource = gfxPlatform::GetPlatform()->GetHardwareVsync();

  RefPtr<VsyncParent> vsyncParent = new VsyncParent();

  vsyncParent->mVsyncDispatcher = vsyncSource->GetRefreshTimerVsyncDispatcher();

  return vsyncParent.forget();

}

VsyncParent::VsyncParent()

  : mObservingVsync(false)

  , mDestroyed(false)

  , mBackgroundThread(NS_GetCurrentThread())

{

  MOZ_ASSERT(mBackgroundThread);

  AssertIsOnBackgroundThread();

}

VsyncParent::~VsyncParent()

{

  // Since we use NS_INLINE_DECL_THREADSAFE_REFCOUNTING, we can't make sure

  // VsyncParent is always released on the background thread.

}

bool

VsyncParent::NotifyVsync(TimeStamp aTimeStamp)

{

  // Called on hardware vsync thread. We should post to current ipc thread.

  MOZ_ASSERT(!IsOnBackgroundThread());

  nsCOMPtr<nsIRunnable> vsyncEvent =

    NewRunnableMethod<TimeStamp>("layout::VsyncParent::DispatchVsyncEvent",

                                 this,

                                 &VsyncParent::DispatchVsyncEvent,

                                 aTimeStamp);

  MOZ_ALWAYS_SUCCEEDS(mBackgroundThread->Dispatch(vsyncEvent, NS_DISPATCH_NORMAL));

  return true;

}

void

VsyncParent::DispatchVsyncEvent(TimeStamp aTimeStamp)

{

  AssertIsOnBackgroundThread();

  // If we call NotifyVsync() when we handle ActorDestroy() message, we might

  // still call DispatchVsyncEvent().

  // Similarly, we might also receive RecvUnobserveVsync() when call

  // NotifyVsync(). We use mObservingVsync and mDestroyed flags to skip this

  // notification.

  if (mObservingVsync && !mDestroyed) {

    Unused << SendNotify(aTimeStamp);

  }

}

mozilla::ipc::IPCResult

VsyncParent::RecvRequestVsyncRate()

{

  AssertIsOnBackgroundThread();

  TimeDuration vsyncRate = gfxPlatform::GetPlatform()->GetHardwareVsync()->GetGlobalDisplay().GetVsyncRate();

  Unused << SendVsyncRate(vsyncRate.ToMilliseconds());

  return IPC_OK();

}

mozilla::ipc::IPCResult

VsyncParent::RecvObserve()

{

  AssertIsOnBackgroundThread();

  if (!mObservingVsync) {

    mVsyncDispatcher->AddChildRefreshTimer(this);

    mObservingVsync = true;

    return IPC_OK();

  }

  return IPC_FAIL_NO_REASON(this);

}

mozilla::ipc::IPCResult

VsyncParent::RecvUnobserve()

{

  AssertIsOnBackgroundThread();

  if (mObservingVsync) {

    mVsyncDispatcher->RemoveChildRefreshTimer(this);

    mObservingVsync = false;

    return IPC_OK();

  }

  return IPC_FAIL_NO_REASON(this);

}

void

VsyncParent::ActorDestroy(ActorDestroyReason aReason)

{

  MOZ_ASSERT(!mDestroyed);

  AssertIsOnBackgroundThread();

  if (mObservingVsync) {

    mVsyncDispatcher->RemoveChildRefreshTimer(this);

  }

  mVsyncDispatcher = nullptr;

  mDestroyed = true;

}

} // namespace layout

} // namespace mozilla