chromium/cc/scheduler/begin_frame_tracker.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_SCHEDULER_BEGIN_FRAME_TRACKER_H_
#define CC_SCHEDULER_BEGIN_FRAME_TRACKER_H_

#include <set>
#include <string>

#include "base/time/time.h"
#include "cc/cc_export.h"
#include "components/viz/common/frame_sinks/begin_frame_args.h"

namespace perfetto {
class EventContext;
namespace protos {
namespace pbzero {
class BeginImplFrameArgsV2;
}
}  // namespace protos
}  // namespace perfetto
namespace cc {

// Microclass to trace and check properties for correct BeginFrameArgs (BFA)
// usage and provide a few helper methods.
//
// With DCHECKs enable, this class checks the following "invariants";
//  * BFA are monotonically increasing.
//  * BFA is valid.
//  * The BFA is only used inside a given period.
//  * A new BFA isn't used before the last BFA is finished with.
//
// With the tracing category "cc.debug.scheduler.frames" enabled the tracker
// will output the following trace information;
//  * Time period for which the BFA is in usage.
//  * The flow of BFA as they are passed between tracking objects.
//
// TODO(mithro): Record stats about the viz::BeginFrameArgs
class CC_EXPORT BeginFrameTracker { … };

}  // namespace cc

#endif  // CC_SCHEDULER_BEGIN_FRAME_TRACKER_H_