[5] | 1 | // Copyright (c) 2013 by István Váradi
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| 2 |
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| 3 | // This file is part of VSCPL, a simple cross-platform utility library
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| 4 |
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| 5 | // Redistribution and use in source and binary forms, with or without
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| 6 | // modification, are permitted provided that the following conditions are met:
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| 7 |
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| 8 | // 1. Redistributions of source code must retain the above copyright notice, this
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| 9 | // list of conditions and the following disclaimer.
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| 10 | // 2. Redistributions in binary form must reproduce the above copyright notice,
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| 11 | // this list of conditions and the following disclaimer in the documentation
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| 12 | // and/or other materials provided with the distribution.
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| 13 |
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| 14 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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| 15 | // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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| 16 | // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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| 17 | // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
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| 18 | // ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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| 19 | // (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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| 20 | // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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| 21 | // ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 22 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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| 23 | // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 24 |
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| 25 | // The views and conclusions contained in the software and documentation are those
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| 26 | // of the authors and should not be interpreted as representing official policies,
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| 27 | // either expressed or implied, of the FreeBSD Project.
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| 28 |
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[6] | 29 | #ifndef HU_VARADIISTVAN_SCPL_POSIX_CONDVAR_H
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| 30 | #define HU_VARADIISTVAN_SCPL_POSIX_CONDVAR_H
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[5] | 31 | //------------------------------------------------------------------------------
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| 32 |
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| 33 | #include "Mutex.h"
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| 34 |
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| 35 | //------------------------------------------------------------------------------
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| 36 |
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| 37 | namespace hu { namespace varadiistvan { namespace scpl {
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| 38 |
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| 39 | //------------------------------------------------------------------------------
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| 40 |
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| 41 | /**
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| 42 | * A condition variable for POSIX threads.
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| 43 | */
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| 44 | class CondVar
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| 45 | {
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| 46 | private:
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| 47 | /**
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| 48 | * Fill the given timespec with the absolute time corresponding to
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| 49 | * the given relative timeout.
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| 50 | */
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| 51 | static void getAbsTime(struct ::timespec& abstime, int timeout);
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| 52 |
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| 53 | /**
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| 54 | * The pthreads structure.
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| 55 | */
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| 56 | pthread_cond_t cond;
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| 57 |
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| 58 | public:
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| 59 | /**
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| 60 | * Construct the condition variable.
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| 61 | */
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| 62 | CondVar();
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| 63 |
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| 64 | /**
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| 65 | * Destroy the condition variable.
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| 66 | */
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| 67 | ~CondVar();
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| 68 |
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| 69 | /**
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| 70 | * Wait for the condition variable.
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| 71 | *
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| 72 | * @param mutex the mutex to unlock and re-lock.
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| 73 | * @param timeout the number of milliseconds to wait at most. If
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| 74 | * negative, the function will wait indefinitely.
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| 75 | *
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| 76 | * @return true, if the condition variable was signalled, false
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| 77 | * if a timeout occured
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| 78 | */
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| 79 | bool wait(Mutex& mutex, int timeout = -1);
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| 80 |
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| 81 | /**
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| 82 | * Signal the condition variable to wake up one thread.
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| 83 | */
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| 84 | void signal();
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| 85 |
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| 86 | /**
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| 87 | * Signal all threads waiting on the condition variable.
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| 88 | */
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| 89 | void broadcast();
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| 90 | };
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| 91 |
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| 92 | //------------------------------------------------------------------------------
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| 93 | // Inline definitions
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| 94 | //------------------------------------------------------------------------------
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| 95 |
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| 96 | inline CondVar::CondVar()
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| 97 | {
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| 98 | pthread_cond_init(&cond, 0);
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| 99 | }
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| 100 |
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| 101 | //------------------------------------------------------------------------------
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| 102 |
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| 103 | inline CondVar::~CondVar()
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| 104 | {
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| 105 | pthread_cond_destroy(&cond);
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| 106 | }
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| 107 |
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| 108 | //------------------------------------------------------------------------------
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| 109 |
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| 110 | inline bool CondVar::wait(Mutex& mutex, int timeout)
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| 111 | {
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| 112 | if (timeout<0) {
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| 113 | pthread_cond_wait(&cond, &mutex.mutex);
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| 114 | return true;
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| 115 | } else {
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| 116 | struct ::timespec abstime;
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| 117 | getAbsTime(abstime, timeout);
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| 118 | return pthread_cond_timedwait(&cond, &mutex.mutex, &abstime)==0;
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| 119 | }
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| 120 | }
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| 121 |
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| 122 | //------------------------------------------------------------------------------
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| 123 |
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| 124 | inline void CondVar::signal()
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| 125 | {
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| 126 | pthread_cond_signal(&cond);
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| 127 | }
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| 128 |
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| 129 | //------------------------------------------------------------------------------
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| 130 |
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| 131 | inline void CondVar::broadcast()
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| 132 | {
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| 133 | pthread_cond_broadcast(&cond);
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| 134 | }
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| 135 |
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| 136 | //------------------------------------------------------------------------------
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| 137 |
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| 138 | } /* namespace hu::varadiistvan::scpl */ } /* namespace hu::varadiistvan */ } /* namespace hu */
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| 139 |
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| 140 | //------------------------------------------------------------------------------
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| 141 | #endif // HU_VARADIISTVAN_SCPL_CONDVAR_H
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| 142 |
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| 143 | // Local Variables:
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| 144 | // mode: C++
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| 145 | // c-basic-offset: 4
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| 146 | // indent-tabs-mode: nil
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| 147 | // End:
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