1 files changed, 105 insertions, 0 deletions
diff --git a/gfx/vr/VRShMem.h b/gfx/vr/VRShMem.h
new file mode 100644
index 0000000000..a10b8189a8
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+++ b/gfx/vr/VRShMem.h
@@ -0,0 +1,105 @@
+/* -*- 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/. */
+
+#ifndef GFX_VR_VRSHMEM_H
+#define GFX_VR_VRSHMEM_H
+
+// This file declares VRShMem, which is used for cross-platform, cross-process
+// communication between VR components.
+// A shared memory handle is opened for the struct of type VRExternalShmem, and
+// different processes write or read members of it to share data. Note that no
+// process should be reading or writing to the same members, except for the
+// versioning members used for synchronization.
+
+#include "moz_external_vr.h"
+#include "base/process.h"  // for base::ProcessHandle
+#include <functional>
+
+namespace mozilla {
+namespace gfx {
+class VRShMem final {
+ public:
+  VRShMem(volatile VRExternalShmem* aShmem, bool aRequiresMutex);
+  ~VRShMem() = default;
+
+  void CreateShMem(bool aCreateOnSharedMemory);
+  void CreateShMemForAndroid();
+  void ClearShMem();
+  void CloseShMem();
+
+  bool JoinShMem();
+  void LeaveShMem();
+
+  void PushBrowserState(VRBrowserState& aBrowserState, bool aNotifyCond);
+  void PullBrowserState(mozilla::gfx::VRBrowserState& aState);
+
+  void PushSystemState(const mozilla::gfx::VRSystemState& aState);
+  void PullSystemState(
+      VRDisplayState& aDisplayState, VRHMDSensorState& aSensorState,
+      VRControllerState (&aControllerState)[kVRControllerMaxCount],
+      bool& aEnumerationCompleted,
+      const std::function<bool()>& aWaitCondition = nullptr);
+
+  void PushWindowState(VRWindowState& aState);
+  void PullWindowState(VRWindowState& aState);
+
+  void PushTelemetryState(VRTelemetryState& aState);
+  void PullTelemetryState(VRTelemetryState& aState);
+
+  void SendIMEState(uint64_t aWindowID, mozilla::gfx::VRFxEventState aImeState);
+  void SendFullscreenState(uint64_t aWindowID, bool aFullscreen);
+  void SendShutdowmState(uint64_t aWindowID);
+
+  bool HasExternalShmem() const { return mExternalShmem != nullptr; }
+  bool IsSharedExternalShmem() const { return mIsSharedExternalShmem; }
+  volatile VRExternalShmem* GetExternalShmem() const;
+  bool IsDisplayStateShutdown() const;
+
+ private:
+  bool IsCreatedOnSharedMemory() const;
+  void SendEvent(uint64_t aWindowID, mozilla::gfx::VRFxEventType aEventType,
+                 mozilla::gfx::VRFxEventState aEventState);
+
+  // mExternalShmem can have one of three sources:
+  // - Allocated outside of this class on the heap and passed in via
+  //   constructor, or acquired via GeckoVRManager (for GeckoView scenario).
+  //   This is usually for scenarios where there is no VR process for cross-
+  //   proc communication, and VRService is receiving the object.
+  //   --> mIsSharedExternalShmem == true, IsCreatedOnSharedMemory() == false
+  //   --> [Windows 7, Mac, Android, Linux]
+  // - Allocated inside this class on the heap. This is usually for scenarios
+  //   where there is no VR process, and VRManager is creating the object.
+  //   --> mIsSharedExternalShmem == false, IsCreatedOnSharedMemory() == false
+  //   --> [Windows 7, Mac, Linux]
+  // - Allocated inside this class on shared memory. This is usually for
+  //   scenarios where there is a VR process and cross-process communication
+  //   is necessary
+  //   --> mIsSharedExternalShmem == false, IsCreatedOnSharedMemory() == true
+  //   --> [Windows 10 with VR process enabled]
+  volatile VRExternalShmem* mExternalShmem = nullptr;
+  // This member is true when mExternalShmem was allocated externally, via
+  // being passed into the constructor or accessed via GeckoVRManager
+  bool mIsSharedExternalShmem;
+
+#if defined(XP_WIN)
+  bool mRequiresMutex;
+#endif
+
+#if defined(XP_MACOSX)
+  int mShmemFD;
+#elif defined(XP_WIN)
+  base::ProcessHandle mShmemFile;
+  base::ProcessHandle mMutex;
+#endif
+
+#if !defined(MOZ_WIDGET_ANDROID)
+  int64_t mBrowserGeneration = 0;
+#endif
+};
+}  // namespace gfx
+}  // namespace mozilla
+
+#endif