1/*
2 Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
3
4 This file is part of libzmq, the ZeroMQ core engine in C++.
5
6 libzmq is free software; you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 As a special exception, the Contributors give you permission to link
12 this library with independent modules to produce an executable,
13 regardless of the license terms of these independent modules, and to
14 copy and distribute the resulting executable under terms of your choice,
15 provided that you also meet, for each linked independent module, the
16 terms and conditions of the license of that module. An independent
17 module is a module which is not derived from or based on this library.
18 If you modify this library, you must extend this exception to your
19 version of the library.
20
21 libzmq is distributed in the hope that it will be useful, but WITHOUT
22 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
23 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
24 License for more details.
25
26 You should have received a copy of the GNU Lesser General Public License
27 along with this program. If not, see <http://www.gnu.org/licenses/>.
28*/
29
30#ifndef __ZMQ_CLOCK_HPP_INCLUDED__
31#define __ZMQ_CLOCK_HPP_INCLUDED__
32
33#include "macros.hpp"
34#include "stdint.hpp"
35
36#if defined ZMQ_HAVE_OSX
37// TODO this is not required in this file, but condition_variable.hpp includes
38// clock.hpp to get these definitions
39#ifndef CLOCK_REALTIME
40#define CLOCK_REALTIME 0
41#endif
42#ifndef HAVE_CLOCK_GETTIME
43#define HAVE_CLOCK_GETTIME
44#endif
45
46#include <mach/clock.h>
47#include <mach/mach.h>
48#include <time.h>
49#include <sys/time.h>
50#endif
51
52namespace zmq
53{
54class clock_t
55{
56 public:
57 clock_t ();
58
59 // CPU's timestamp counter. Returns 0 if it's not available.
60 static uint64_t rdtsc ();
61
62 // High precision timestamp.
63 static uint64_t now_us ();
64
65 // Low precision timestamp. In tight loops generating it can be
66 // 10 to 100 times faster than the high precision timestamp.
67 uint64_t now_ms ();
68
69 private:
70 // TSC timestamp of when last time measurement was made.
71 uint64_t _last_tsc;
72
73 // Physical time corresponding to the TSC above (in milliseconds).
74 uint64_t _last_time;
75
76 ZMQ_NON_COPYABLE_NOR_MOVABLE (clock_t)
77};
78}
79
80#endif
81