chromium/base/trace_event/auto_open_close_event.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_TRACE_EVENT_AUTO_OPEN_CLOSE_EVENT_H_
#define BASE_TRACE_EVENT_AUTO_OPEN_CLOSE_EVENT_H_

#include "base/check.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/thread_checker.h"
#include "base/time/time.h"
#include "base/trace_event/trace_event.h"

namespace base {
namespace trace_event {

// Class for tracing events that support "auto-opening" and "auto-closing".
// "auto-opening" = if the trace event is started (call Begin() before
// tracing is started,the trace event will be opened, with the start time
// being the time that the trace event was actually started.
// "auto-closing" = if the trace event is started but not ended by the time
// tracing ends, then the trace event will be automatically closed at the
// end of tracing.
// |category| must be known at compile-time in order to be used in trace macros.
// Hence, it's passed as a class templace argument.
template <const char* category>
class AutoOpenCloseEvent : public TraceLog::AsyncEnabledStateObserver { … };

}  // namespace trace_event
}  // namespace base

#endif  // BASE_TRACE_EVENT_AUTO_OPEN_CLOSE_EVENT_H_