1 files changed, 53 insertions, 0 deletions
diff --git a/gfx/thebes/SoftwareVsyncSource.h b/gfx/thebes/SoftwareVsyncSource.h
new file mode 100644
index 0000000000..0a86432db3
--- /dev/null
+++ b/gfx/thebes/SoftwareVsyncSource.h
@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * 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_SOFTWARE_VSYNC_SOURCE_H
+#define GFX_SOFTWARE_VSYNC_SOURCE_H
+
+#include "mozilla/DataMutex.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/TimeStamp.h"
+#include "base/thread.h"
+#include "nsISupportsImpl.h"
+#include "VsyncSource.h"
+
+namespace mozilla::gfx {
+
+// Fallback option to use a software timer to mimic vsync. Useful for gtests
+// To mimic a hardware vsync thread, we create a dedicated software timer
+// vsync thread.
+class SoftwareVsyncSource : public VsyncSource {
+ public:
+  explicit SoftwareVsyncSource(const TimeDuration& aInitialVsyncRate);
+  virtual ~SoftwareVsyncSource();
+
+  void EnableVsync() override;
+  void DisableVsync() override;
+  bool IsVsyncEnabled() override;
+  bool IsInSoftwareVsyncThread();
+  void NotifyVsync(const TimeStamp& aVsyncTimestamp,
+                   const TimeStamp& aOutputTimestamp) override;
+  TimeDuration GetVsyncRate() override;
+  void ScheduleNextVsync(TimeStamp aVsyncTimestamp);
+  void Shutdown() override;
+
+  // Can be called on any thread
+  void SetVsyncRate(const TimeDuration& aNewRate);
+
+ protected:
+  // Use a chromium thread because nsITimers* fire on the main thread
+  base::Thread* mVsyncThread;
+  RefPtr<CancelableRunnable> mCurrentVsyncTask;  // only access on vsync thread
+  bool mVsyncEnabled;                            // Only access on main thread
+
+ private:
+  DataMutex<TimeDuration> mVsyncRate;  // can be accessed on any thread
+};
+
+}  // namespace mozilla::gfx
+
+#endif /* GFX_SOFTWARE_VSYNC_SOURCE_H */