gfx/vr/service/VRService.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 GFX_VR_SERVICE_VRSERVICE_H
   8 #define GFX_VR_SERVICE_VRSERVICE_H
   9
  10 #include "moz_external_vr.h"
  11 #include "base/process.h"  // for base::ProcessHandle
  12 #include "mozilla/Atomics.h"
  13 #include "mozilla/TimeStamp.h"
  14 #include "mozilla/UniquePtr.h"
  15 #include "nsCOMPtr.h"
  16
  17 class nsIThread;
  18 namespace mozilla {
  19 class BackgroundHangMonitor;
  20 namespace gfx {
  21
  22 class VRSession;
  23 class VRShMem;
  24
  25 static const int kVRFrameTimingHistoryDepth = 100;
  26
  27 class VRService {
  28  public:
  29   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(VRService)
  30   static already_AddRefed<VRService> Create(
  31       volatile VRExternalShmem* aShmem = nullptr);
  32
  33   void Refresh();
  34   void Start();
  35   void Stop();
  36
  37  private:
  38   explicit VRService(volatile VRExternalShmem* aShmem);
  39   ~VRService();
  40
  41   void StopInternal(bool aFromDtor);
  42
  43   bool InitShmem();
  44   void PushState(const mozilla::gfx::VRSystemState& aState);
  45   void PullState(mozilla::gfx::VRBrowserState& aState);
  46
  47   /**
  48    * VRSystemState contains the most recent state of the VR
  49    * system, to be shared with the browser by Shmem.
  50    * mSystemState is the VR Service copy of this data, which
  51    * is memcpy'ed atomically to the Shmem.
  52    * VRSystemState is written by the VR Service, but read-only
  53    * by the browser.
  54    */
  55   VRSystemState mSystemState;
  56   /**
  57    * VRBrowserState contains the most recent state of the browser.
  58    * mBrowserState is memcpy'ed from the Shmem atomically
  59    */
  60   VRBrowserState mBrowserState;
  61
  62   UniquePtr<VRSession> mSession;
  63   nsCOMPtr<nsIThread> mServiceThread;
  64   // Only ever accessed on the service thread.
  65   UniquePtr<mozilla::BackgroundHangMonitor> mBackgroundHangMonitor;
  66
  67   Atomic<bool> mShutdownRequested;
  68
  69   // Note: mShmem doesn't support RefPtr; thus, do not share this private
  70   // pointer so that its lifetime can still be controlled by VRService
  71   VRShMem* mShmem;
  72   VRHapticState mLastHapticState[kVRHapticsMaxCount];
  73   TimeStamp mFrameStartTime[kVRFrameTimingHistoryDepth];
  74
  75   bool IsInServiceThread();
  76   void UpdateHaptics();
  77
  78   /**
  79    * The VR Service thread is a state machine that always has one
  80    * task queued depending on the state.
  81    *
  82    * VR Service thread state task functions:
  83    */
  84   void ServiceInitialize();
  85   void ServiceShutdown();
  86   void ServiceWaitForImmersive();
  87   void ServiceImmersiveMode();
  88 };
  89
  90 }  // namespace gfx
  91 }  // namespace mozilla
  92
  93 #endif  // GFX_VR_SERVICE_VRSERVICE_H