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1 | #ifndef BOOST_SMART_PTR_DETAIL_YIELD_K_HPP_INCLUDED |
2 | #define BOOST_SMART_PTR_DETAIL_YIELD_K_HPP_INCLUDED | |
3 | ||
4 | // MS compatible compilers support #pragma once | |
5 | ||
6 | #if defined(_MSC_VER) && (_MSC_VER >= 1020) | |
7 | # pragma once | |
8 | #endif | |
9 | ||
10 | // | |
11 | // yield_k.hpp | |
12 | // | |
13 | // Copyright (c) 2008 Peter Dimov | |
14 | // Copyright (c) Microsoft Corporation 2014 | |
15 | // | |
16 | // void yield( unsigned k ); | |
17 | // | |
18 | // Typical use: | |
19 | // | |
20 | // for( unsigned k = 0; !try_lock(); ++k ) yield( k ); | |
21 | // | |
22 | // Distributed under the Boost Software License, Version 1.0. | |
23 | // See accompanying file LICENSE_1_0.txt or copy at | |
24 | // http://www.boost.org/LICENSE_1_0.txt | |
25 | // | |
26 | ||
27 | #include <boost/config.hpp> | |
28 | #include <boost/predef.h> | |
29 | ||
30 | #if BOOST_PLAT_WINDOWS_RUNTIME | |
31 | #include <thread> | |
32 | #endif | |
33 | ||
34 | // BOOST_SMT_PAUSE | |
35 | ||
b32b8144 | 36 | #if defined(_MSC_VER) && _MSC_VER >= 1310 && ( defined(_M_IX86) || defined(_M_X64) ) && !defined(__c2__) |
7c673cae FG |
37 | |
38 | extern "C" void _mm_pause(); | |
39 | ||
40 | #define BOOST_SMT_PAUSE _mm_pause(); | |
41 | ||
42 | #elif defined(__GNUC__) && ( defined(__i386__) || defined(__x86_64__) ) | |
43 | ||
44 | #define BOOST_SMT_PAUSE __asm__ __volatile__( "rep; nop" : : : "memory" ); | |
45 | ||
46 | #endif | |
47 | ||
48 | // | |
49 | ||
50 | #if defined( WIN32 ) || defined( _WIN32 ) || defined( __WIN32__ ) || defined( __CYGWIN__ ) | |
51 | ||
52 | #if defined( BOOST_USE_WINDOWS_H ) | |
53 | # include <windows.h> | |
54 | #endif | |
55 | ||
56 | namespace boost | |
57 | { | |
58 | ||
59 | namespace detail | |
60 | { | |
61 | ||
62 | #if !defined( BOOST_USE_WINDOWS_H ) && !BOOST_PLAT_WINDOWS_RUNTIME | |
63 | #if !BOOST_COMP_CLANG || !defined __MINGW32__ | |
64 | extern "C" void __stdcall Sleep( unsigned long ms ); | |
65 | #else | |
66 | #include <_mingw.h> | |
67 | #if !defined __MINGW64_VERSION_MAJOR | |
68 | extern "C" void __stdcall Sleep( unsigned long ms ); | |
69 | #else | |
70 | extern "C" __declspec(dllimport) void __stdcall Sleep( unsigned long ms ); | |
71 | #endif | |
72 | #endif | |
73 | #endif | |
74 | ||
75 | inline void yield( unsigned k ) | |
76 | { | |
77 | if( k < 4 ) | |
78 | { | |
79 | } | |
80 | #if defined( BOOST_SMT_PAUSE ) | |
81 | else if( k < 16 ) | |
82 | { | |
83 | BOOST_SMT_PAUSE | |
84 | } | |
85 | #endif | |
86 | #if !BOOST_PLAT_WINDOWS_RUNTIME | |
87 | else if( k < 32 ) | |
88 | { | |
89 | Sleep( 0 ); | |
90 | } | |
91 | else | |
92 | { | |
93 | Sleep( 1 ); | |
94 | } | |
95 | #else | |
96 | else | |
97 | { | |
98 | // Sleep isn't supported on the Windows Runtime. | |
99 | std::this_thread::yield(); | |
100 | } | |
101 | #endif | |
102 | } | |
103 | ||
104 | } // namespace detail | |
105 | ||
106 | } // namespace boost | |
107 | ||
108 | #elif defined( BOOST_HAS_PTHREADS ) | |
109 | ||
110 | #ifndef _AIX | |
111 | #include <sched.h> | |
112 | #else | |
113 | // AIX's sched.h defines ::var which sometimes conflicts with Lambda's var | |
114 | extern "C" int sched_yield(void); | |
115 | #endif | |
116 | ||
117 | #include <time.h> | |
118 | ||
119 | namespace boost | |
120 | { | |
121 | ||
122 | namespace detail | |
123 | { | |
124 | ||
125 | inline void yield( unsigned k ) | |
126 | { | |
127 | if( k < 4 ) | |
128 | { | |
129 | } | |
130 | #if defined( BOOST_SMT_PAUSE ) | |
131 | else if( k < 16 ) | |
132 | { | |
133 | BOOST_SMT_PAUSE | |
134 | } | |
135 | #endif | |
136 | else if( k < 32 || k & 1 ) | |
137 | { | |
138 | sched_yield(); | |
139 | } | |
140 | else | |
141 | { | |
142 | // g++ -Wextra warns on {} or {0} | |
143 | struct timespec rqtp = { 0, 0 }; | |
144 | ||
145 | // POSIX says that timespec has tv_sec and tv_nsec | |
146 | // But it doesn't guarantee order or placement | |
147 | ||
148 | rqtp.tv_sec = 0; | |
149 | rqtp.tv_nsec = 1000; | |
150 | ||
151 | nanosleep( &rqtp, 0 ); | |
152 | } | |
153 | } | |
154 | ||
155 | } // namespace detail | |
156 | ||
157 | } // namespace boost | |
158 | ||
159 | #else | |
160 | ||
161 | namespace boost | |
162 | { | |
163 | ||
164 | namespace detail | |
165 | { | |
166 | ||
167 | inline void yield( unsigned ) | |
168 | { | |
169 | } | |
170 | ||
171 | } // namespace detail | |
172 | ||
173 | } // namespace boost | |
174 | ||
175 | #endif | |
176 | ||
177 | #endif // #ifndef BOOST_SMART_PTR_DETAIL_YIELD_K_HPP_INCLUDED |