system/ulib/async-testutils/include/lib/async-testutils/time-keeper.h

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#pragma once

#include <lib/zx/time.h>

namespace async {

// An abstract class responsible for dispatching timer expirations.
class TimerDispatcher {
public:
    virtual ~TimerDispatcher() = default;

    // Signal that a timer has expired.
    virtual void FireTimer() = 0;
};

// An abstract class that tells time and registers timers to signal expirations
// with the provided callbacks.
class TimeKeeper {
public:
    virtual ~TimeKeeper() = default;

    // Returns the current time.
    virtual zx::time Now() const = 0;

    // Registers a time and a dispatcher so that when the current time is equal
    // to or later than |deadline|, |dispatcher| will signal that the associated
    // timer has expired.
    virtual void RegisterTimer(zx::time deadline, TimerDispatcher* dispatcher) = 0;

    // Cancel all timers registered with |dispatcher|.
    virtual void CancelTimers(TimerDispatcher* dispatcher) = 0;
};

} // namespace