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 #if defined(XP_WIN)
  11 #  include "nsTString.h"
  12 #endif
  13
  14 namespace mozilla {
  15 namespace gfx {
  16
  17 #if defined(XP_WIN)
  18 class WaitForMutex {
  19  public:
  20   explicit WaitForMutex(HANDLE handle) : mHandle(handle), mStatus(false) {
  21     MOZ_ASSERT(mHandle);
  22
  23     DWORD dwWaitResult;
  24     dwWaitResult = WaitForSingleObject(mHandle,    // handle to mutex
  25                                        INFINITE);  // no time-out interval
  26
  27     switch (dwWaitResult) {
  28       // The thread got ownership of the mutex
  29       case WAIT_OBJECT_0:
  30         mStatus = true;
  31         break;
  32
  33       // The thread got ownership of an abandoned mutex
  34       // The shmem is in an indeterminate state
  35       case WAIT_ABANDONED:
  36         mStatus = false;
  37         break;
  38       default:
  39         mStatus = false;
  40         break;
  41     }
  42   }
  43
  44   ~WaitForMutex() {
  45     if (mHandle && !ReleaseMutex(mHandle)) {
  46 #  ifdef MOZILLA_INTERNAL_API
  47       nsAutoCString msg;
  48       msg.AppendPrintf("WaitForMutex %d ReleaseMutex error \"%lu\".", mHandle,
  49                        GetLastError());
  50       NS_WARNING(msg.get());
  51 #  endif
  52       MOZ_ASSERT(false, "Failed to release mutex.");
  53     }
  54   }
  55
  56   bool GetStatus() { return mStatus; }
  57
  58  private:
  59   HANDLE mHandle;
  60   bool mStatus;
  61 };
  62 #endif
  63
  64 }  // namespace gfx
  65 }  // namespace mozilla
  66
  67 #endif /* GFX_VR_MUTEX_H */