1// boost thread_clock.cpp -----------------------------------------------------------//
2
3// Copyright Beman Dawes 1994, 2006, 2008
4// Copyright Vicente J. Botet Escriba 2009-2011
5
6// Distributed under the Boost Software License, Version 1.0.
7// See http://www.boost.org/LICENSE_1_0.txt
8
9// See http://www.boost.org/libs/chrono for documentation.
10
11//--------------------------------------------------------------------------------------//
12
13#include <boost/chrono/config.hpp>
14#include <boost/chrono/thread_clock.hpp>
15#include <cassert>
16#include <boost/assert.hpp>
17
18#if !defined(__VXWORKS__)
19# include <sys/times.h>
20#endif
21# include <pthread.h>
22# include <unistd.h>
23
24namespace boost { namespace chrono {
25
26 thread_clock::time_point thread_clock::now( ) BOOST_NOEXCEPT
27 {
28 struct timespec ts;
29#if defined CLOCK_THREAD_CPUTIME_ID
30 // get the timespec associated to the thread clock
31 if ( ::clock_gettime( CLOCK_THREAD_CPUTIME_ID, tp: &ts ) )
32#else
33 // get the current thread
34 pthread_t pth=pthread_self();
35 // get the clock_id associated to the current thread
36 clockid_t clock_id;
37 pthread_getcpuclockid(pth, &clock_id);
38 // get the timespec associated to the thread clock
39 if ( ::clock_gettime( clock_id, &ts ) )
40#endif
41 {
42 BOOST_ASSERT(0 && "Boost::Chrono - Internal Error");
43 }
44
45 // transform to nanoseconds
46 return time_point(duration(
47 static_cast<thread_clock::rep>( ts.tv_sec ) * 1000000000 + ts.tv_nsec));
48
49 }
50
51#if !defined BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING
52 thread_clock::time_point thread_clock::now( system::error_code & ec )
53 {
54 struct timespec ts;
55#if defined CLOCK_THREAD_CPUTIME_ID
56 // get the timespec associated to the thread clock
57 if ( ::clock_gettime( CLOCK_THREAD_CPUTIME_ID, tp: &ts ) )
58#else
59 // get the current thread
60 pthread_t pth=pthread_self();
61 // get the clock_id associated to the current thread
62 clockid_t clock_id;
63 pthread_getcpuclockid(pth, &clock_id);
64 // get the timespec associated to the thread clock
65 if ( ::clock_gettime( clock_id, &ts ) )
66#endif
67 {
68 if (::boost::chrono::is_throws(ec))
69 {
70 boost::throw_exception(
71 e: system::system_error(
72 errno,
73 ::boost::system::system_category(),
74 "chrono::thread_clock" ));
75 }
76 else
77 {
78 ec.assign( errno, cat: ::boost::system::system_category() );
79 return time_point();
80 }
81 }
82 if (!::boost::chrono::is_throws(ec))
83 {
84 ec.clear();
85 }
86 // transform to nanoseconds
87 return time_point(duration(
88 static_cast<thread_clock::rep>( ts.tv_sec ) * 1000000000 + ts.tv_nsec));
89
90 }
91#endif
92} }
93

source code of boost/libs/chrono/include/boost/chrono/detail/inlined/posix/thread_clock.hpp