1 files changed, 121 insertions, 0 deletions
diff --git a/layout/ipc/VsyncParent.cpp b/layout/ipc/VsyncParent.cpp
new file mode 100644
index 000000000..8ffe8abc4
--- /dev/null
+++ b/layout/ipc/VsyncParent.cpp
@@ -0,0 +1,121 @@
+/* -*- 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 "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>(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);
+  }
+}
+
+bool
+VsyncParent::RecvRequestVsyncRate()
+{
+  AssertIsOnBackgroundThread();
+  TimeDuration vsyncRate = gfxPlatform::GetPlatform()->GetHardwareVsync()->GetGlobalDisplay().GetVsyncRate();
+  Unused << SendVsyncRate(vsyncRate.ToMilliseconds());
+  return true;
+}
+
+bool
+VsyncParent::RecvObserve()
+{
+  AssertIsOnBackgroundThread();
+  if (!mObservingVsync) {
+    mVsyncDispatcher->AddChildRefreshTimer(this);
+    mObservingVsync = true;
+    return true;
+  }
+  return false;
+}
+
+bool
+VsyncParent::RecvUnobserve()
+{
+  AssertIsOnBackgroundThread();
+  if (mObservingVsync) {
+    mVsyncDispatcher->RemoveChildRefreshTimer(this);
+    mObservingVsync = false;
+    return true;
+  }
+  return false;
+}
+
+void
+VsyncParent::ActorDestroy(ActorDestroyReason aReason)
+{
+  MOZ_ASSERT(!mDestroyed);
+  AssertIsOnBackgroundThread();
+  if (mObservingVsync) {
+    mVsyncDispatcher->RemoveChildRefreshTimer(this);
+  }
+  mVsyncDispatcher = nullptr;
+  mDestroyed = true;
+}
+
+} // namespace layout
+} // namespace mozilla