// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_CLOCK_H_
#define BASE_CLOCK_H_
#include "base/base_export.h"
#include "base/time/time.h"
namespace base {
// A Clock is an interface for objects that vend Times. It is
// intended to be able to test the behavior of classes with respect to
// time.
//
// See DefaultClock (base/time/default_clock.h) for the default
// implementation that simply uses Time::Now().
//
// (An implementation that uses Time::SystemTime() should be added as
// needed.)
//
// See SimpleTestClock (base/test/simple_test_clock.h) for a simple
// test implementation.
//
// See TickClock (base/time/tick_clock.h) for the equivalent interface for
// TimeTicks.
class BASE_EXPORT Clock {
public:
virtual ~Clock();
// Now() must be safe to call from any thread. The caller cannot
// make any ordering assumptions about the returned Time. For
// example, the system clock may change to an earlier time.
virtual Time Now() = 0;
};
} // namespace base
#endif // BASE_CLOCK_H_