gfx/vr/VRShMem.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_VRSHMEM_H
   8 #define GFX_VR_VRSHMEM_H
   9
  10 // This file declares VRShMem, which is used for cross-platform, cross-process
  11 // communication between VR components.
  12 // A shared memory handle is opened for the struct of type VRExternalShmem, and
  13 // different processes write or read members of it to share data. Note that no
  14 // process should be reading or writing to the same members, except for the
  15 // versioning members used for synchronization.
  16
  17 #include "moz_external_vr.h"
  18 #include "base/process.h"  // for base::ProcessHandle
  19 #include <functional>
  20
  21 namespace mozilla {
  22 namespace gfx {
  23 class VRShMem final {
  24  public:
  25   VRShMem(volatile VRExternalShmem* aShmem, bool aRequiresMutex);
  26   ~VRShMem() = default;
  27
  28   void CreateShMem(bool aCreateOnSharedMemory);
  29   void CreateShMemForAndroid();
  30   void ClearShMem();
  31   void CloseShMem();
  32
  33   bool JoinShMem();
  34   void LeaveShMem();
  35
  36   void PushBrowserState(VRBrowserState& aBrowserState, bool aNotifyCond);
  37   void PullBrowserState(mozilla::gfx::VRBrowserState& aState);
  38
  39   void PushSystemState(const mozilla::gfx::VRSystemState& aState);
  40   void PullSystemState(
  41       VRDisplayState& aDisplayState, VRHMDSensorState& aSensorState,
  42       VRControllerState (&aControllerState)[kVRControllerMaxCount],
  43       bool& aEnumerationCompleted,
  44       const std::function<bool()>& aWaitCondition = nullptr);
  45
  46   void PushWindowState(VRWindowState& aState);
  47   void PullWindowState(VRWindowState& aState);
  48
  49   void PushTelemetryState(VRTelemetryState& aState);
  50   void PullTelemetryState(VRTelemetryState& aState);
  51
  52   void SendIMEState(uint64_t aWindowID, mozilla::gfx::VRFxEventState aImeState);
  53   void SendFullscreenState(uint64_t aWindowID, bool aFullscreen);
  54   void SendShutdowmState(uint64_t aWindowID);
  55
  56   bool HasExternalShmem() const { return mExternalShmem != nullptr; }
  57   bool IsSharedExternalShmem() const { return mIsSharedExternalShmem; }
  58   volatile VRExternalShmem* GetExternalShmem() const;
  59   bool IsDisplayStateShutdown() const;
  60
  61  private:
  62   bool IsCreatedOnSharedMemory() const;
  63   void SendEvent(uint64_t aWindowID, mozilla::gfx::VRFxEventType aEventType,
  64                  mozilla::gfx::VRFxEventState aEventState);
  65
  66   // mExternalShmem can have one of three sources:
  67   // - Allocated outside of this class on the heap and passed in via
  68   //   constructor, or acquired via GeckoVRManager (for GeckoView scenario).
  69   //   This is usually for scenarios where there is no VR process for cross-
  70   //   proc communication, and VRService is receiving the object.
  71   //   --> mIsSharedExternalShmem == true, IsCreatedOnSharedMemory() == false
  72   //   --> [Windows 7, Mac, Android, Linux]
  73   // - Allocated inside this class on the heap. This is usually for scenarios
  74   //   where there is no VR process, and VRManager is creating the object.
  75   //   --> mIsSharedExternalShmem == false, IsCreatedOnSharedMemory() == false
  76   //   --> [Windows 7, Mac, Linux]
  77   // - Allocated inside this class on shared memory. This is usually for
  78   //   scenarios where there is a VR process and cross-process communication
  79   //   is necessary
  80   //   --> mIsSharedExternalShmem == false, IsCreatedOnSharedMemory() == true
  81   //   --> [Windows 10 with VR process enabled]
  82   volatile VRExternalShmem* mExternalShmem = nullptr;
  83   // This member is true when mExternalShmem was allocated externally, via
  84   // being passed into the constructor or accessed via GeckoVRManager
  85   bool mIsSharedExternalShmem;
  86
  87 #if defined(XP_WIN)
  88   bool mRequiresMutex;
  89 #endif
  90
  91 #if defined(XP_MACOSX)
  92   int mShmemFD;
  93 #elif defined(XP_WIN)
  94   base::ProcessHandle mShmemFile;
  95   base::ProcessHandle mMutex;
  96 #endif
  97
  98 #if !defined(MOZ_WIDGET_ANDROID)
  99   int64_t mBrowserGeneration = 0;
 100 #endif
 101 };
 102 }  // namespace gfx
 103 }  // namespace mozilla
 104
 105 #endif