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1 | ////////////////////////////////////////////////////////////////////////////// |
2 | // | |
3 | // (C) Copyright Ion Gaztanaga 2012-2013. Distributed under the Boost | |
4 | // Software License, Version 1.0. (See accompanying file | |
5 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
6 | // | |
7 | // See http://www.boost.org/libs/interprocess for documentation. | |
8 | // | |
9 | ////////////////////////////////////////////////////////////////////////////// | |
10 | ||
11 | #ifndef BOOST_INTERPROCESS_SYNC_DETAIL_COMMON_ALGORITHMS_HPP | |
12 | #define BOOST_INTERPROCESS_SYNC_DETAIL_COMMON_ALGORITHMS_HPP | |
13 | ||
14 | #ifndef BOOST_CONFIG_HPP | |
15 | # include <boost/config.hpp> | |
16 | #endif | |
17 | # | |
18 | #if defined(BOOST_HAS_PRAGMA_ONCE) | |
19 | # pragma once | |
20 | #endif | |
21 | ||
22 | #include <boost/interprocess/detail/config_begin.hpp> | |
23 | #include <boost/interprocess/detail/workaround.hpp> | |
24 | ||
25 | #include <boost/interprocess/sync/spin/wait.hpp> | |
26 | ||
27 | namespace boost { | |
28 | namespace interprocess { | |
29 | namespace ipcdetail { | |
30 | ||
31 | template<class MutexType> | |
32 | bool try_based_timed_lock(MutexType &m, const boost::posix_time::ptime &abs_time) | |
33 | { | |
34 | //Same as lock() | |
35 | if(abs_time == boost::posix_time::pos_infin){ | |
36 | m.lock(); | |
37 | return true; | |
38 | } | |
39 | //Always try to lock to achieve POSIX guarantees: | |
40 | // "Under no circumstance shall the function fail with a timeout if the mutex | |
41 | // can be locked immediately. The validity of the abs_timeout parameter need not | |
42 | // be checked if the mutex can be locked immediately." | |
43 | else if(m.try_lock()){ | |
44 | return true; | |
45 | } | |
46 | else{ | |
47 | spin_wait swait; | |
48 | while(microsec_clock::universal_time() < abs_time){ | |
49 | if(m.try_lock()){ | |
50 | return true; | |
51 | } | |
52 | swait.yield(); | |
53 | } | |
54 | return false; | |
55 | } | |
56 | } | |
57 | ||
58 | template<class MutexType> | |
59 | void try_based_lock(MutexType &m) | |
60 | { | |
61 | if(!m.try_lock()){ | |
62 | spin_wait swait; | |
63 | do{ | |
64 | if(m.try_lock()){ | |
65 | break; | |
66 | } | |
67 | else{ | |
68 | swait.yield(); | |
69 | } | |
70 | } | |
71 | while(1); | |
72 | } | |
73 | } | |
74 | ||
11fdf7f2 TL |
75 | template<class MutexType> |
76 | void timed_based_lock(MutexType &m, unsigned const uCheckPeriodSec) | |
77 | { | |
78 | const boost::posix_time::time_duration dur(0, 0, uCheckPeriodSec); | |
79 | boost::posix_time::ptime deadline(microsec_clock::universal_time()+dur); | |
80 | if(!m.timed_lock(deadline)){ | |
81 | spin_wait swait; | |
82 | do{ | |
83 | deadline = microsec_clock::universal_time()+dur; | |
84 | if(m.timed_lock(deadline)){ | |
85 | break; | |
86 | } | |
87 | else{ | |
88 | swait.yield(); | |
89 | } | |
90 | } | |
91 | while(1); | |
92 | } | |
93 | } | |
94 | ||
95 | template<class MutexType> | |
96 | void timed_based_timed_lock(MutexType &m, const boost::posix_time::ptime &abs_time, unsigned const uCheckPeriodSec) | |
97 | { | |
98 | const boost::posix_time::time_duration dur(0, 0, uCheckPeriodSec); | |
99 | boost::posix_time::ptime deadline(microsec_clock::universal_time()+dur); | |
100 | if(abs_time <= deadline){ | |
101 | m.timed_lock(abs_time); | |
102 | } | |
103 | else if(!m.timed_lock(deadline)){ | |
104 | spin_wait swait; | |
105 | do{ | |
106 | deadline = microsec_clock::universal_time()+dur; | |
107 | if(m.timed_lock(deadline)){ | |
108 | break; | |
109 | } | |
110 | else{ | |
111 | swait.yield(); | |
112 | } | |
113 | } | |
114 | while(1); | |
115 | } | |
116 | } | |
117 | ||
7c673cae FG |
118 | } //namespace ipcdetail |
119 | } //namespace interprocess | |
120 | } //namespace boost | |
121 | ||
122 | #include <boost/interprocess/detail/config_end.hpp> | |
123 | ||
124 | #endif //BOOST_INTERPROCESS_SYNC_DETAIL_COMMON_ALGORITHMS_HPP |