chromium/third_party/blink/renderer/platform/scheduler/common/auto_advancing_virtual_time_domain.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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_COMMON_AUTO_ADVANCING_VIRTUAL_TIME_DOMAIN_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_COMMON_AUTO_ADVANCING_VIRTUAL_TIME_DOMAIN_H_

#include "base/memory/raw_ptr.h"
#include "base/task/sequence_manager/time_domain.h"
#include "base/task/task_observer.h"
#include "base/time/tick_clock.h"
#include "base/time/time.h"
#include "base/time/time_override.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/scheduler/common/process_time_override_coordinator.h"

namespace blink {
namespace scheduler {
class SchedulerHelper;

// A time domain that runs tasks sequentially in time order but doesn't sleep
// between delayed tasks. Because AutoAdvancingVirtualTimeDomain may override
// Time/TimeTicks in a multi-threaded context, it must outlive any thread that
// may call Time::Now() or TimeTicks::Now(). In practice, this means
// AutoAdvancingVirtualTimeDomain can never be destroyed in production and acts
// as a one-way switch. In tests, it should only be destroyed after all threads
// have been joined.
//
// KEY: A-E are delayed tasks
// |    A   B C  D           E  (Execution with RealTimeDomain)
// |-----------------------------> time
//
// |ABCDE                       (Execution with AutoAdvancingVirtualTimeDomain)
// |-----------------------------> time
class PLATFORM_EXPORT AutoAdvancingVirtualTimeDomain
    : public base::sequence_manager::TimeDomain,
      public base::TaskObserver { … };

}  // namespace scheduler
}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_COMMON_AUTO_ADVANCING_VIRTUAL_TIME_DOMAIN_H_