clock.h 1.13 KB
Newer Older
gejun's avatar
gejun committed
1 2 3 4
// 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.

5 6
#ifndef BUTIL_CLOCK_H_
#define BUTIL_CLOCK_H_
gejun's avatar
gejun committed
7

8 9
#include "butil/base_export.h"
#include "butil/time/time.h"
gejun's avatar
gejun committed
10

11
namespace butil {
gejun's avatar
gejun committed
12 13 14 15 16

// 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.
//
17
// See DefaultClock (butil/time/default_clock.h) for the default
gejun's avatar
gejun committed
18 19 20 21 22
// implementation that simply uses Time::Now().
//
// (An implementation that uses Time::SystemTime() should be added as
// needed.)
//
23
// See SimpleTestClock (butil/test/simple_test_clock.h) for a simple
gejun's avatar
gejun committed
24 25
// test implementation.
//
26
// See TickClock (butil/time/tick_clock.h) for the equivalent interface for
gejun's avatar
gejun committed
27
// TimeTicks.
28
class BUTIL_EXPORT Clock {
gejun's avatar
gejun committed
29 30 31 32 33 34 35 36 37
 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;
};

38
}  // namespace butil
gejun's avatar
gejun committed
39

40
#endif  // BUTIL_CLOCK_H_