blob: a956cc0c974168883d99badc46961e076b983493 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
#ifndef BOOST_SMART_PTR_DETAIL_YIELD_K_HPP_INCLUDED
#define BOOST_SMART_PTR_DETAIL_YIELD_K_HPP_INCLUDED
// MS compatible compilers support #pragma once
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
//
// yield_k.hpp
//
// Copyright (c) 2008 Peter Dimov
//
// void yield( unsigned k );
//
// Typical use:
//
// for( unsigned k = 0; !try_lock(); ++k ) yield( k );
//
// Distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
//
#include <boost/config.hpp>
// BOOST_SMT_PAUSE
#if defined(_MSC_VER) && _MSC_VER >= 1310 && ( defined(_M_IX86) || defined(_M_X64) )
extern "C" void _mm_pause();
#pragma intrinsic( _mm_pause )
#define BOOST_SMT_PAUSE _mm_pause();
#elif defined(__GNUC__) && ( defined(__i386__) || defined(__x86_64__) )
#define BOOST_SMT_PAUSE __asm__ __volatile__( "rep; nop" : : : "memory" );
#endif
//
#if defined( WIN32 ) || defined( _WIN32 ) || defined( __WIN32__ ) || defined( __CYGWIN__ )
#if defined( BOOST_USE_WINDOWS_H )
# include <windows.h>
#endif
namespace boost
{
namespace detail
{
#if !defined( BOOST_USE_WINDOWS_H )
extern "C" void __stdcall Sleep( unsigned ms );
#endif
inline void yield( unsigned k )
{
if( k < 4 )
{
}
#if defined( BOOST_SMT_PAUSE )
else if( k < 16 )
{
BOOST_SMT_PAUSE
}
#endif
else if( k < 32 )
{
Sleep( 0 );
}
else
{
Sleep( 1 );
}
}
} // namespace detail
} // namespace boost
#elif defined( BOOST_HAS_PTHREADS )
#include <sched.h>
#include <time.h>
namespace boost
{
namespace detail
{
inline void yield( unsigned k )
{
if( k < 4 )
{
}
#if defined( BOOST_SMT_PAUSE )
else if( k < 16 )
{
BOOST_SMT_PAUSE
}
#endif
else if( k < 32 || k & 1 )
{
sched_yield();
}
else
{
// g++ -Wextra warns on {} or {0}
struct timespec rqtp = { 0, 0 };
// POSIX says that timespec has tv_sec and tv_nsec
// But it doesn't guarantee order or placement
rqtp.tv_sec = 0;
rqtp.tv_nsec = 1000;
nanosleep( &rqtp, 0 );
}
}
} // namespace detail
} // namespace boost
#else
namespace boost
{
namespace detail
{
inline void yield( unsigned )
{
}
} // namespace detail
} // namespace boost
#endif
#endif // #ifndef BOOST_SMART_PTR_DETAIL_YIELD_K_HPP_INCLUDED
|
Swift