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 | // boost/smart_ptr/detail/yield_k.hpp |
11 | // |
12 | // Copyright 2008, 2020 Peter Dimov |
13 | // |
14 | // inline void boost::detail::yield( unsigned k ); |
15 | // |
16 | // Typical use: |
17 | // for( unsigned k = 0; !try_lock(); ++k ) yield( k ); |
18 | // |
19 | // Distributed under the Boost Software License, Version 1.0. |
20 | // https://www.boost.org/LICENSE_1_0.txt |
21 | |
22 | #include <boost/smart_ptr/detail/sp_thread_pause.hpp> |
23 | #include <boost/smart_ptr/detail/sp_thread_sleep.hpp> |
24 | #include <boost/config.hpp> |
25 | |
26 | namespace boost |
27 | { |
28 | |
29 | namespace detail |
30 | { |
31 | |
32 | inline void yield( unsigned k ) |
33 | { |
34 | // Experiments on Windows and Fedora 32 show that a single pause, |
35 | // followed by an immediate sp_thread_sleep(), is best. |
36 | |
37 | if( k == 0 ) |
38 | { |
39 | sp_thread_pause(); |
40 | } |
41 | else |
42 | { |
43 | sp_thread_sleep(); |
44 | } |
45 | } |
46 | |
47 | } // namespace detail |
48 | |
49 | } // namespace boost |
50 | |
51 | #endif // #ifndef BOOST_SMART_PTR_DETAIL_YIELD_K_HPP_INCLUDED |
52 | |