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 | #ifdef _OPENMP |
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14 | #include <omp.h> |
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15 | #endif |
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16 | #include <errno.h> |
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17 | #include <assert.h> |
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18 | #include <limits.h> |
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19 | #include "concurrent.h" |
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20 | |
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21 | //#define LOG(x) do {}while(false) |
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22 | #define LOG(x) fprintf(stderr, "Error: %d\n", (x)) |
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23 | |
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24 | namespace concurrent { |
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25 | /* ======================= Mutex ======================= */ |
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26 | Mutex::Mutex() throw(int) |
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27 | { |
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28 | int result = pthread_mutex_init(&mutex, NULL); |
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29 | if (result != 0) { |
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30 | LOG(result); |
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31 | throw result; |
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32 | } |
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33 | } |
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34 | |
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35 | Mutex::~Mutex() |
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36 | { |
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37 | int result = pthread_mutex_destroy(&mutex); |
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38 | if (result != 0) { |
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39 | LOG(result); |
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40 | } |
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41 | } |
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42 | |
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43 | void Mutex::lock() throw(int) |
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44 | { |
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45 | int result = pthread_mutex_lock(&mutex); |
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46 | if (result != 0) { |
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47 | LOG(result); |
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48 | throw result; |
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49 | } |
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50 | } |
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51 | |
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52 | bool Mutex::try_lock() throw(int) |
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53 | { |
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54 | int result = pthread_mutex_trylock(&mutex); |
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55 | if (result == 0) { |
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56 | return true; |
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57 | } |
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58 | if (result == EBUSY) { |
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59 | return false; |
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60 | } |
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61 | LOG(result); |
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62 | throw result; |
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63 | } |
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64 | |
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65 | void Mutex::unlock() throw(int) |
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66 | { |
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67 | int result = pthread_mutex_unlock(&mutex); |
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68 | if (result != 0) { |
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69 | LOG(result); |
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70 | throw result; |
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71 | } |
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72 | } |
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73 | |
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74 | /* ======================= Semaphore ======================= */ |
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75 | Semaphore::Semaphore(unsigned initial) throw(int) |
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76 | { |
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77 | //mutex = PTHREAD_MUTEX_INITIALIZER; |
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78 | //cond = PTHREAD_COND_INITIALIZER; |
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79 | sem = initial; |
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80 | |
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81 | int result = pthread_mutex_init(&mutex, NULL); |
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82 | if (result != 0) { |
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83 | LOG(result); |
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84 | throw result; |
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85 | } |
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86 | |
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87 | result = pthread_cond_init(&cond, NULL); |
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88 | if (result != 0) { |
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89 | pthread_mutex_destroy(&mutex); |
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90 | LOG(result); |
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91 | throw result; |
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92 | } |
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93 | } |
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94 | |
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95 | Semaphore::~Semaphore() |
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96 | { |
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97 | int result = pthread_mutex_destroy(&mutex); |
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98 | result = pthread_cond_destroy(&cond); |
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99 | } |
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100 | |
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101 | void Semaphore::up(unsigned amount) throw(int) |
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102 | { |
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103 | assert(0 < amount && amount <= UINT_MAX - sem); |
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104 | int result = pthread_mutex_lock(&mutex); |
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105 | if (result == 0) { |
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106 | sem += amount; |
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107 | result = pthread_cond_signal(&cond); |
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108 | int result2 = pthread_mutex_unlock(&mutex); |
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109 | if (result == 0 && result2 == 0) { |
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110 | return; |
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111 | } |
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112 | if (result != 0 && result2 != 0) { |
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113 | LOG(result); |
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114 | result = 0; |
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115 | } |
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116 | if (result == 0) { |
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117 | result = result2; |
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118 | } |
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119 | } |
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120 | LOG(result); |
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121 | throw result; |
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122 | } |
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123 | |
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124 | void Semaphore::down(unsigned amount) throw(int) |
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125 | { |
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126 | assert(0 < amount); |
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127 | int result = pthread_mutex_lock(&mutex); |
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128 | if (result == 0) { |
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129 | while (sem < amount) { |
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130 | result = pthread_cond_wait(&cond, &mutex); |
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131 | if (result != 0) { |
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132 | LOG(result); |
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133 | break; |
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134 | } |
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135 | } |
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136 | if (sem >= amount) { |
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137 | sem -= amount; |
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138 | } |
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139 | int result2 = pthread_mutex_unlock(&mutex); |
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140 | if (result == 0 && result2 == 0) { |
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141 | return; |
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142 | } |
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143 | if (result != 0 && result2 != 0) { |
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144 | LOG(result); |
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145 | result = 0; |
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146 | } |
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147 | if (result == 0) { |
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148 | result = result2; |
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149 | } |
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150 | } |
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151 | LOG(result); |
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152 | throw result; |
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153 | } |
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154 | |
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155 | /* ======================= Broker ======================= */ |
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156 | Broker::Broker(bool (*producer)(void *context) throw(PCException), |
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157 | void (*consumer)(void *context) throw(PCException)) |
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158 | { |
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159 | this->producer = producer; |
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160 | this->consumer = consumer; |
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161 | } |
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162 | |
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163 | Broker::~Broker() |
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164 | { |
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165 | } |
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166 | |
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167 | void Broker::enableNested() |
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168 | { |
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169 | #ifdef _OPENMP |
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170 | omp_set_nested(1); |
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171 | #endif |
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172 | } |
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173 | |
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174 | void Broker::disableNested() |
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175 | { |
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176 | #ifdef _OPENMP |
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177 | omp_set_nested(0); |
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178 | #endif |
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179 | } |
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180 | |
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181 | void Broker::setNestedState(bool nested) |
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182 | { |
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183 | #ifdef _OPENMP |
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184 | omp_set_nested(static_cast<int>(nested)); |
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185 | #endif |
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186 | } |
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187 | |
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188 | bool Broker::getNestedState() |
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189 | { |
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190 | #ifdef _OPENMP |
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191 | return omp_get_nested() ? true : false; |
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192 | #else |
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193 | return false; |
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194 | #endif |
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195 | } |
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196 | |
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197 | void Broker::runProducerAsMasterThread(void *context, unsigned do_ahead) |
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198 | throw(PCException) |
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199 | { |
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200 | _run(context, do_ahead, ProdAsMaster); |
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201 | } |
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202 | |
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203 | void Broker::runConsumerAsMasterThread(void *context, unsigned do_ahead) |
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204 | throw(PCException) |
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205 | { |
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206 | _run(context, do_ahead, ConsAsMaster); |
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207 | } |
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208 | |
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209 | void Broker::run(void *context, unsigned do_ahead) throw(PCException) |
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210 | { |
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211 | _run(context, do_ahead, Unspecified); |
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212 | } |
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213 | |
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214 | void Broker::_run(void *context, unsigned do_ahead, ThreadSpec threadSpec) |
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215 | throw(PCException) |
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216 | { |
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217 | assert(do_ahead > 0); |
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218 | #ifdef _OPENMP |
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219 | PCException *prodEx = NULL; |
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220 | PCException *consEx = NULL; |
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221 | unsigned queuedJobs = 0; |
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222 | int consumerTerminated = 0; |
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223 | Semaphore semaphore_for_consumer; |
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224 | Semaphore semaphore_for_producer(do_ahead); |
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225 | |
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226 | #pragma omp parallel num_threads(2) \ |
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227 | shared(semaphore_for_consumer, semaphore_for_producer, \ |
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228 | consumerTerminated, queuedJobs) |
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229 | { |
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230 | //fprintf(stderr, "run: %p %d\n", context, omp_get_thread_num()); |
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231 | bool runProd = true; |
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232 | if (threadSpec == Unspecified) { |
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233 | #pragma omp single |
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234 | { |
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235 | runProd = false; |
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236 | } |
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237 | } else { |
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238 | bool isMaster = false; |
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239 | #pragma omp master |
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240 | { |
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241 | isMaster = true; |
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242 | } |
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243 | if (threadSpec == ProdAsMaster) { |
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244 | runProd = isMaster; |
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245 | } else { // ConsAsMaster |
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246 | runProd = ! isMaster; |
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247 | } |
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248 | } |
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249 | |
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250 | if (runProd) { // producer |
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251 | for (;;) { |
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252 | semaphore_for_producer.down(); |
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253 | int consumerDead = 0; |
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254 | #pragma omp atomic |
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255 | consumerDead += consumerTerminated; |
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256 | if (consumerDead) { |
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257 | break; |
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258 | } |
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259 | try { |
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260 | bool produced = producer(context); |
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261 | if (! produced) { |
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262 | break; |
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263 | } |
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264 | } catch (PCException &e) { |
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265 | prodEx = &e; |
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266 | break; |
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267 | } |
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268 | #pragma omp atomic |
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269 | queuedJobs++; |
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270 | semaphore_for_consumer.up(); |
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271 | } |
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272 | // additional 'up' to give consumer a chance to terminate. |
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273 | semaphore_for_consumer.up(); |
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274 | } else { // consumer |
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275 | for (;;) { |
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276 | semaphore_for_consumer.down(); |
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277 | unsigned remainingJobs = 0U; |
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278 | #pragma omp atomic |
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279 | remainingJobs += queuedJobs; |
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280 | if (remainingJobs == 0U) { |
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281 | break; |
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282 | } |
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283 | #pragma omp atomic |
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284 | queuedJobs--; |
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285 | try { |
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286 | consumer(context); |
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287 | } catch (PCException &e) { |
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288 | consEx = &e; |
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289 | break; |
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290 | } |
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291 | semaphore_for_producer.up(); |
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292 | } |
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293 | #pragma omp atomic |
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294 | consumerTerminated++; |
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295 | // additional 'up' to give producer a chance to terminate. |
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296 | semaphore_for_producer.up(); |
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297 | } |
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298 | } |
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299 | if (prodEx) { |
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300 | prodEx->raise(); |
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301 | } else if (consEx) { |
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302 | consEx->raise(); |
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303 | } |
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304 | #else |
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305 | runSequential(context); |
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306 | #endif |
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307 | } |
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308 | |
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309 | void Broker::runSequential(void *context) throw(PCException) |
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310 | { |
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311 | for (;;) { |
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312 | bool produced = producer(context); |
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313 | if (! produced) { |
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314 | break; |
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315 | } |
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316 | consumer(context); |
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317 | } |
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318 | } |
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319 | |
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320 | } // namespace |
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