gfx/vr/gfxVRMutex.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_MUTEX_H
   8 #define GFX_VR_MUTEX_H
   9
  10 namespace mozilla {
  11 namespace gfx {
  12
  13 #if defined(XP_WIN)
  14 class WaitForMutex {
  15  public:
  16   explicit WaitForMutex(HANDLE handle) : mHandle(handle), mStatus(false) {
  17     MOZ_ASSERT(mHandle);
  18
  19     DWORD dwWaitResult;
  20     dwWaitResult = WaitForSingleObject(mHandle,    // handle to mutex
  21                                        INFINITE);  // no time-out interval
  22
  23     switch (dwWaitResult) {
  24       // The thread got ownership of the mutex
  25       case WAIT_OBJECT_0:
  26         mStatus = true;
  27         break;
  28
  29       // The thread got ownership of an abandoned mutex
  30       // The shmem is in an indeterminate state
  31       case WAIT_ABANDONED:
  32         mStatus = false;
  33         break;
  34       default:
  35         mStatus = false;
  36         break;
  37     }
  38   }
  39
  40   ~WaitForMutex() {
  41     if (mHandle && !ReleaseMutex(mHandle)) {
  42 #  ifdef MOZILLA_INTERNAL_API
  43       nsAutoCString msg;
  44       msg.AppendPrintf("WaitForMutex %d ReleaseMutex error \"%lu\".", mHandle,
  45                        GetLastError());
  46       NS_WARNING(msg.get());
  47 #  endif
  48       MOZ_ASSERT(false, "Failed to release mutex.");
  49     }
  50   }
  51
  52   bool GetStatus() { return mStatus; }
  53
  54  private:
  55   HANDLE mHandle;
  56   bool mStatus;
  57 };
  58 #endif
  59
  60 }  // namespace gfx
  61 }  // namespace mozilla
  62
  63 #endif /* GFX_VR_MUTEX_H */