1 files changed, 67 insertions, 0 deletions
diff --git a/gfx/vr/gfxVRMutex.h b/gfx/vr/gfxVRMutex.h
new file mode 100644
index 0000000000..9a487e067b
--- /dev/null
+++ b/gfx/vr/gfxVRMutex.h
@@ -0,0 +1,67 @@
+/* -*- 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_MUTEX_H
+#define GFX_VR_MUTEX_H
+
+#if defined(XP_WIN)
+#  include "nsTString.h"
+#endif
+
+namespace mozilla {
+namespace gfx {
+
+#if defined(XP_WIN)
+class WaitForMutex {
+ public:
+  explicit WaitForMutex(HANDLE handle) : mHandle(handle), mStatus(false) {
+    MOZ_ASSERT(mHandle);
+
+    DWORD dwWaitResult;
+    dwWaitResult = WaitForSingleObject(mHandle,    // handle to mutex
+                                       INFINITE);  // no time-out interval
+
+    switch (dwWaitResult) {
+      // The thread got ownership of the mutex
+      case WAIT_OBJECT_0:
+        mStatus = true;
+        break;
+
+      // The thread got ownership of an abandoned mutex
+      // The shmem is in an indeterminate state
+      case WAIT_ABANDONED:
+        mStatus = false;
+        break;
+      default:
+        mStatus = false;
+        break;
+    }
+  }
+
+  ~WaitForMutex() {
+    if (mHandle && !ReleaseMutex(mHandle)) {
+#  ifdef MOZILLA_INTERNAL_API
+      nsAutoCString msg;
+      msg.AppendPrintf("WaitForMutex %p ReleaseMutex error \"%lu\".", mHandle,
+                       GetLastError());
+      NS_WARNING(msg.get());
+#  endif
+      MOZ_ASSERT(false, "Failed to release mutex.");
+    }
+  }
+
+  bool GetStatus() { return mStatus; }
+
+ private:
+  HANDLE mHandle;
+  bool mStatus;
+};
+#endif
+
+}  // namespace gfx
+}  // namespace mozilla
+
+#endif /* GFX_VR_MUTEX_H */