[2392] | 1 | // |
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| 2 | // C++ Interface: concurrent |
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| 3 | // |
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| 4 | // Description: |
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| 5 | // |
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| 6 | // |
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| 7 | // Author: Kohji Nakamura <k.nakamura@nao.ac.jp>, (C) 2012 |
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| 8 | // |
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| 9 | // Copyright: See COPYING file that comes with this distribution |
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| 10 | // |
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| 11 | // |
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| 12 | #include <stdio.h> |
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| 13 | #include <omp.h> |
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| 14 | #include <errno.h> |
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| 15 | #include <assert.h> |
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| 16 | #include <limits.h> |
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| 17 | #include "concurrent.h" |
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| 18 | |
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| 19 | //#define LOG(x) do {}while(false) |
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| 20 | #define LOG(x) fprintf(stderr, "Error: %d\n", (x)) |
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| 21 | |
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| 22 | namespace concurrent { |
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| 23 | /* ======================= Mutex ======================= */ |
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| 24 | Mutex::Mutex() throw(int) |
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| 25 | { |
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| 26 | int result = pthread_mutex_init(&mutex, NULL); |
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| 27 | if (result != 0) { |
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| 28 | LOG(result); |
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| 29 | throw result; |
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| 30 | } |
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| 31 | } |
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| 32 | |
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| 33 | Mutex::~Mutex() |
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| 34 | { |
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| 35 | int result = pthread_mutex_destroy(&mutex); |
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| 36 | if (result != 0) { |
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| 37 | LOG(result); |
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| 38 | } |
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| 39 | } |
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| 40 | |
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| 41 | void Mutex::lock() throw(int) |
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| 42 | { |
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| 43 | int result = pthread_mutex_lock(&mutex); |
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| 44 | if (result != 0) { |
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| 45 | LOG(result); |
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| 46 | throw result; |
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| 47 | } |
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| 48 | } |
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| 49 | |
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| 50 | bool Mutex::try_lock() throw(int) |
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| 51 | { |
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| 52 | int result = pthread_mutex_trylock(&mutex); |
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| 53 | if (result == 0) { |
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| 54 | return true; |
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| 55 | } |
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| 56 | if (result == EBUSY) { |
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| 57 | return false; |
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| 58 | } |
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| 59 | LOG(result); |
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| 60 | throw result; |
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| 61 | } |
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| 62 | |
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| 63 | void Mutex::unlock() throw(int) |
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| 64 | { |
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| 65 | int result = pthread_mutex_unlock(&mutex); |
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| 66 | if (result != 0) { |
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| 67 | LOG(result); |
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| 68 | throw result; |
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| 69 | } |
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| 70 | } |
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| 71 | |
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| 72 | /* ======================= Semaphore ======================= */ |
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| 73 | Semaphore::Semaphore(unsigned initial) throw(int) |
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| 74 | { |
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| 75 | //mutex = PTHREAD_MUTEX_INITIALIZER; |
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| 76 | //cond = PTHREAD_COND_INITIALIZER; |
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| 77 | sem = initial; |
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| 78 | |
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| 79 | int result = pthread_mutex_init(&mutex, NULL); |
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| 80 | if (result != 0) { |
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| 81 | LOG(result); |
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| 82 | throw result; |
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| 83 | } |
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| 84 | |
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| 85 | result = pthread_cond_init(&cond, NULL); |
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| 86 | if (result != 0) { |
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| 87 | pthread_mutex_destroy(&mutex); |
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| 88 | LOG(result); |
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| 89 | throw result; |
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| 90 | } |
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| 91 | } |
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| 92 | |
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| 93 | Semaphore::~Semaphore() |
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| 94 | { |
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| 95 | int result = pthread_mutex_destroy(&mutex); |
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| 96 | result = pthread_cond_destroy(&cond); |
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| 97 | } |
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| 98 | |
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| 99 | void Semaphore::up(unsigned amount) throw(int) |
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| 100 | { |
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| 101 | assert(0 < amount && amount <= UINT_MAX - sem); |
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| 102 | int result = pthread_mutex_lock(&mutex); |
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| 103 | if (result == 0) { |
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| 104 | sem += amount; |
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| 105 | result = pthread_cond_signal(&cond); |
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| 106 | int result2 = pthread_mutex_unlock(&mutex); |
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| 107 | if (result == 0 && result2 == 0) { |
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| 108 | return; |
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| 109 | } |
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| 110 | if (result != 0 && result2 != 0) { |
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| 111 | LOG(result); |
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| 112 | result = 0; |
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| 113 | } |
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| 114 | if (result == 0) { |
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| 115 | result = result2; |
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| 116 | } |
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| 117 | } |
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| 118 | LOG(result); |
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| 119 | throw result; |
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| 120 | } |
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| 121 | |
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| 122 | void Semaphore::down(unsigned amount) throw(int) |
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| 123 | { |
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| 124 | assert(0 < amount); |
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| 125 | int result = pthread_mutex_lock(&mutex); |
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| 126 | if (result == 0) { |
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| 127 | while (sem < amount) { |
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| 128 | result = pthread_cond_wait(&cond, &mutex); |
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| 129 | if (result != 0) { |
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| 130 | LOG(result); |
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| 131 | break; |
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| 132 | } |
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| 133 | } |
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| 134 | if (sem >= amount) { |
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| 135 | sem -= amount; |
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| 136 | } |
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| 137 | int result2 = pthread_mutex_unlock(&mutex); |
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| 138 | if (result == 0 && result2 == 0) { |
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| 139 | return; |
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| 140 | } |
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| 141 | if (result != 0 && result2 != 0) { |
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| 142 | LOG(result); |
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| 143 | result = 0; |
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| 144 | } |
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| 145 | if (result == 0) { |
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| 146 | result = result2; |
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| 147 | } |
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| 148 | } |
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| 149 | LOG(result); |
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| 150 | throw result; |
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| 151 | } |
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| 152 | |
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| 153 | /* ======================= Broker ======================= */ |
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| 154 | Broker::Broker(bool (*producer)(void *context) throw(PCException), |
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| 155 | void (*consumer)(void *context) throw(PCException)) |
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| 156 | { |
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| 157 | this->producer = producer; |
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| 158 | this->consumer = consumer; |
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| 159 | } |
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| 160 | |
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| 161 | Broker::~Broker() |
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| 162 | { |
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| 163 | } |
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| 164 | |
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| 165 | void Broker::enableNested() |
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| 166 | { |
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| 167 | omp_set_nested(1); |
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| 168 | } |
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| 169 | |
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| 170 | void Broker::disableNested() |
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| 171 | { |
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| 172 | omp_set_nested(0); |
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| 173 | } |
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| 174 | |
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| 175 | void Broker::setNestedState(bool nested) |
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| 176 | { |
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| 177 | omp_set_nested(static_cast<int>(nested)); |
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| 178 | } |
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| 179 | |
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| 180 | bool Broker::getNestedState() |
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| 181 | { |
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| 182 | return omp_get_nested() ? true : false; |
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| 183 | } |
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| 184 | |
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| 185 | void Broker::runProducerAsMasterThread(void *context, unsigned do_ahead) |
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| 186 | throw(PCException) |
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| 187 | { |
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| 188 | _run(context, do_ahead, ProdAsMaster); |
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| 189 | } |
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| 190 | |
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| 191 | void Broker::runConsumerAsMasterThread(void *context, unsigned do_ahead) |
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| 192 | throw(PCException) |
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| 193 | { |
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| 194 | _run(context, do_ahead, ConsAsMaster); |
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| 195 | } |
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| 196 | |
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| 197 | void Broker::run(void *context, unsigned do_ahead) throw(PCException) |
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| 198 | { |
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| 199 | _run(context, do_ahead, Unspecified); |
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| 200 | } |
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| 201 | |
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| 202 | void Broker::_run(void *context, unsigned do_ahead, ThreadSpec threadSpec) |
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| 203 | throw(PCException) |
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| 204 | { |
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| 205 | assert(do_ahead > 0); |
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| 206 | #ifdef _OPENMP |
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| 207 | PCException *prodEx = NULL; |
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| 208 | PCException *consEx = NULL; |
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| 209 | unsigned queuedJobs = 0; |
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| 210 | int consumerTerminated = 0; |
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| 211 | Semaphore semaphore_for_consumer; |
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| 212 | Semaphore semaphore_for_producer(do_ahead); |
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| 213 | |
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| 214 | #pragma omp parallel num_threads(2) \ |
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| 215 | shared(semaphore_for_consumer, semaphore_for_producer, \ |
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| 216 | consumerTerminated, queuedJobs) |
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| 217 | { |
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| 218 | //fprintf(stderr, "run: %p %d\n", context, omp_get_thread_num()); |
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| 219 | bool runProd = true; |
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| 220 | if (threadSpec == Unspecified) { |
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| 221 | #pragma omp single |
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| 222 | { |
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| 223 | runProd = false; |
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| 224 | } |
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| 225 | } else { |
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| 226 | bool isMaster = false; |
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| 227 | #pragma omp master |
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| 228 | { |
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| 229 | isMaster = true; |
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| 230 | } |
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| 231 | if (threadSpec == ProdAsMaster) { |
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| 232 | runProd = isMaster; |
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| 233 | } else { // ConsAsMaster |
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| 234 | runProd = ! isMaster; |
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| 235 | } |
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| 236 | } |
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| 237 | |
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| 238 | if (runProd) { // producer |
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| 239 | for (;;) { |
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| 240 | semaphore_for_producer.down(); |
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| 241 | int consumerDead = 0; |
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| 242 | #pragma omp atomic |
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| 243 | consumerDead += consumerTerminated; |
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| 244 | if (consumerDead) { |
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| 245 | break; |
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| 246 | } |
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| 247 | try { |
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| 248 | bool produced = producer(context); |
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| 249 | if (! produced) { |
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| 250 | break; |
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| 251 | } |
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| 252 | } catch (PCException &e) { |
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| 253 | prodEx = &e; |
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| 254 | break; |
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| 255 | } |
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| 256 | #pragma omp atomic |
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| 257 | queuedJobs++; |
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| 258 | semaphore_for_consumer.up(); |
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| 259 | } |
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| 260 | // additional 'up' to give consumer a chance to terminate. |
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| 261 | semaphore_for_consumer.up(); |
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| 262 | } else { // consumer |
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| 263 | for (;;) { |
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| 264 | semaphore_for_consumer.down(); |
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| 265 | unsigned remainingJobs = 0U; |
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| 266 | #pragma omp atomic |
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| 267 | remainingJobs += queuedJobs; |
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| 268 | if (remainingJobs == 0U) { |
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| 269 | break; |
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| 270 | } |
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| 271 | #pragma omp atomic |
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| 272 | queuedJobs--; |
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| 273 | try { |
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| 274 | consumer(context); |
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| 275 | } catch (PCException &e) { |
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| 276 | consEx = &e; |
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| 277 | break; |
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| 278 | } |
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| 279 | semaphore_for_producer.up(); |
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| 280 | } |
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| 281 | #pragma omp atomic |
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| 282 | consumerTerminated++; |
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| 283 | // additional 'up' to give producer a chance to terminate. |
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| 284 | semaphore_for_producer.up(); |
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| 285 | } |
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| 286 | } |
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| 287 | if (prodEx) { |
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| 288 | prodEx->raise(); |
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| 289 | } else if (consEx) { |
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| 290 | consEx->raise(); |
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| 291 | } |
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| 292 | #else |
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| 293 | runSequential(context); |
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| 294 | #endif |
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| 295 | } |
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| 296 | |
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| 297 | void Broker::runSequential(void *context) throw(PCException) |
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| 298 | { |
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| 299 | for (;;) { |
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| 300 | bool produced = producer(context); |
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| 301 | if (! produced) { |
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| 302 | break; |
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| 303 | } |
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| 304 | consumer(context); |
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| 305 | } |
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| 306 | } |
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| 307 | |
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| 308 | } // namespace |
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