layout/ipc/VsyncChild.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_layout_ipc_VsyncChild_h
   8 #define mozilla_layout_ipc_VsyncChild_h
   9
  10 #include "mozilla/layout/PVsyncChild.h"
  11 #include "nsISupportsImpl.h"
  12 #include "mozilla/RefPtr.h"
  13
  14 namespace mozilla {
  15
  16 class VsyncObserver;
  17
  18 namespace ipc {
  19 class BackgroundChildImpl;
  20 }  // namespace ipc
  21
  22 namespace layout {
  23
  24 // The PVsyncChild actor receives a vsync event from the main process and
  25 // delivers it to the child process. Currently this is restricted to the main
  26 // thread only. The actor will stay alive until the process dies or its
  27 // PVsyncParent actor dies.
  28 class VsyncChild final : public PVsyncChild {
  29   NS_INLINE_DECL_REFCOUNTING(VsyncChild)
  30
  31   friend class mozilla::ipc::BackgroundChildImpl;
  32   friend class PVsyncChild;
  33
  34  public:
  35   // Hide the SendObserve/SendUnobserve in PVsyncChild. We add an flag
  36   // mObservingVsync to handle the race problem of unobserving vsync event.
  37   bool SendObserve();
  38   bool SendUnobserve();
  39
  40   // Bind a VsyncObserver into VsyncChild after ipc channel connected.
  41   void SetVsyncObserver(VsyncObserver* aVsyncObserver);
  42   // GetVsyncRate is a getter for mVsyncRate which sends a requests to
  43   // VsyncParent to retreive the hardware vsync rate if mVsyncRate
  44   // hasn't already been set.
  45   TimeDuration GetVsyncRate();
  46   // VsyncRate is a getter for mVsyncRate which always returns
  47   // mVsyncRate directly, potentially returning
  48   // TimeDuration::Forever() if mVsyncRate hasn't been set by calling
  49   // GetVsyncRate.
  50   TimeDuration VsyncRate();
  51
  52  private:
  53   VsyncChild();
  54   virtual ~VsyncChild();
  55
  56   mozilla::ipc::IPCResult RecvNotify(const VsyncEvent& aVsync);
  57   mozilla::ipc::IPCResult RecvVsyncRate(const float& aVsyncRate);
  58   virtual void ActorDestroy(ActorDestroyReason aActorDestroyReason) override;
  59
  60   bool mObservingVsync;
  61   bool mIsShutdown;
  62
  63   // The content side vsync observer.
  64   RefPtr<VsyncObserver> mObserver;
  65   TimeDuration mVsyncRate;
  66 };
  67
  68 }  // namespace layout
  69 }  // namespace mozilla
  70
  71 #endif  // mozilla_layout_ipc_VsyncChild_h