1 | /* |
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2 | * |
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3 | * This is a simple real-time applications XXX. |
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4 | * |
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5 | * Other POSIX facilities such as XXX, condition, .. is also used |
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6 | * |
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7 | * The license and distribution terms for this file may be |
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8 | * found in the file LICENSE in this distribution or at |
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9 | * http://www.rtems.com/license/LICENSE. |
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10 | */ |
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11 | |
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12 | #ifdef HAVE_CONFIG_H |
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13 | #include "config.h" |
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14 | #endif |
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15 | |
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16 | #define CONFIGURE_INIT |
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17 | #include "system.h" |
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18 | #include <pthread.h> /* thread facilities */ |
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19 | #include <signal.h> /* signal facilities */ |
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20 | #include <unistd.h> /* sleep facilities */ |
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21 | #include <sched.h> /* schedule facilities */ |
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22 | #include <time.h> /* time facilities */ |
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23 | #include <stdio.h> /* console facilities */ |
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24 | #include "tmacros.h" |
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25 | |
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26 | #define NUMBER_THREADS 2 |
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27 | pthread_t ThreadIds[NUMBER_THREADS]; |
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28 | |
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29 | typedef struct { |
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30 | pthread_mutex_t lock; |
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31 | pthread_cond_t rcond; |
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32 | pthread_cond_t wcond; |
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33 | int lock_count; /* < 0 .. Held by writer. */ |
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34 | /* > 0 .. Held by lock_count readers. */ |
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35 | /* = 0 .. Held by nobody. */ |
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36 | int waiting_writers; /* Count of waiting writers. */ |
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37 | } lock_t; |
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38 | |
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39 | volatile bool reader_cleanup_ran; |
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40 | volatile bool release_read_lock_ran; |
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41 | volatile bool writer_cleanup_ran; |
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42 | |
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43 | void waiting_reader_cleanup(void *arg); |
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44 | void lock_for_read(void *arg); |
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45 | void release_read_lock(void *arg); |
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46 | void waiting_writer_cleanup(void *arg); |
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47 | void lock_for_write(lock_t *l); |
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48 | void release_write_lock(void *arg); |
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49 | void initialize_lock_t(lock_t *l); |
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50 | void *ReaderThread(void *arg); |
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51 | void *WriterThread(void *arg); |
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52 | |
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53 | void waiting_reader_cleanup(void *arg) |
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54 | { |
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55 | lock_t *l; |
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56 | |
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57 | reader_cleanup_ran = TRUE; |
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58 | |
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59 | l = (lock_t *) arg; |
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60 | pthread_mutex_unlock(&l->lock); |
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61 | } |
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62 | |
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63 | void lock_for_read(void *arg) |
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64 | { |
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65 | lock_t *l = arg; |
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66 | |
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67 | pthread_mutex_lock(&l->lock); |
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68 | pthread_cleanup_push(waiting_reader_cleanup, l); |
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69 | while ((l->lock_count < 0) && (l->waiting_writers != 0)) |
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70 | pthread_cond_wait(&l->rcond, &l->lock); |
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71 | l->lock_count++; |
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72 | reader_cleanup_ran = FALSE; |
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73 | |
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74 | /* |
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75 | * Note the pthread_cleanup_pop executes |
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76 | * waiting_reader_cleanup. |
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77 | */ |
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78 | pthread_cleanup_pop(1); |
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79 | |
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80 | if ( reader_cleanup_ran == FALSE ) { |
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81 | puts( "reader cleanup did not run" ); |
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82 | rtems_test_exit(0); |
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83 | } |
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84 | } |
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85 | |
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86 | void release_read_lock(void *arg) |
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87 | { |
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88 | lock_t *l = arg; |
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89 | |
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90 | release_read_lock_ran = TRUE; |
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91 | pthread_mutex_lock(&l->lock); |
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92 | if (--l->lock_count == 0) |
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93 | pthread_cond_signal(&l->wcond); |
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94 | pthread_mutex_unlock(&l->lock); |
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95 | } |
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96 | |
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97 | void waiting_writer_cleanup(void *arg) |
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98 | { |
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99 | lock_t *l = arg; |
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100 | |
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101 | writer_cleanup_ran = TRUE; |
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102 | |
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103 | if ((--l->waiting_writers == 0) && (l->lock_count >= 0)) { |
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104 | /* |
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105 | * This only happens if we have been canceled. |
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106 | */ |
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107 | pthread_cond_broadcast(&l->wcond); |
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108 | } |
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109 | pthread_mutex_unlock(&l->lock); |
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110 | } |
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111 | |
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112 | void lock_for_write(lock_t *l) |
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113 | { |
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114 | pthread_mutex_lock(&l->lock); |
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115 | l->waiting_writers++; |
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116 | l->lock_count = -1; |
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117 | |
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118 | pthread_cleanup_push(waiting_writer_cleanup, l); |
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119 | |
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120 | while (l->lock_count != 0) |
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121 | pthread_cond_wait(&l->wcond, &l->lock); |
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122 | l->lock_count = -1; |
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123 | |
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124 | /* |
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125 | * Note the pthread_cleanup_pop executes |
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126 | * waiting_writer_cleanup. |
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127 | */ |
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128 | writer_cleanup_ran = FALSE; |
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129 | pthread_cleanup_pop(1); |
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130 | |
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131 | if ( writer_cleanup_ran == FALSE ) { |
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132 | puts( "writer cleanup did not run" ); |
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133 | rtems_test_exit(0); |
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134 | } |
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135 | } |
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136 | |
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137 | void release_write_lock(void *arg) |
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138 | { |
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139 | lock_t *l = arg; |
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140 | |
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141 | writer_cleanup_ran = TRUE; |
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142 | |
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143 | /* pthread_mutex_lock(&l->lock); */ |
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144 | l->lock_count = 0; |
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145 | if (l->waiting_writers == 0) |
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146 | pthread_cond_broadcast(&l->rcond); |
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147 | else |
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148 | pthread_cond_signal(&l->wcond); |
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149 | /* pthread_mutex_unlock(&l->lock); */ |
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150 | } |
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151 | |
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152 | |
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153 | /* |
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154 | * This function is called to initialize the read/write lock. |
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155 | */ |
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156 | void initialize_lock_t(lock_t *l) |
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157 | { |
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158 | pthread_mutexattr_t mutexattr; /* mutex attributes */ |
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159 | pthread_condattr_t condattr; /* condition attributes */ |
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160 | |
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161 | if (pthread_mutexattr_init (&mutexattr) != 0) { |
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162 | perror ("Error in mutex attribute init\n"); |
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163 | } |
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164 | if (pthread_mutex_init (&l->lock,&mutexattr) != 0) { |
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165 | perror ("Error in mutex init"); |
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166 | } |
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167 | |
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168 | if (pthread_condattr_init (&condattr) != 0) { |
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169 | perror ("Error in condition attribute init\n"); |
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170 | } |
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171 | if (pthread_cond_init (&l->wcond,&condattr) != 0) { |
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172 | perror ("Error in write condition init"); |
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173 | } |
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174 | if (pthread_cond_init (&l->rcond,&condattr) != 0) { |
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175 | perror ("Error in read condition init"); |
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176 | } |
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177 | |
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178 | l->lock_count = 0; |
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179 | l->waiting_writers = 0; |
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180 | } |
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181 | |
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182 | void *ReaderThread(void *arg) |
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183 | { |
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184 | lock_t *l = arg; |
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185 | |
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186 | puts("Lock for read"); |
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187 | lock_for_read(l); |
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188 | puts("cleanup push for read"); |
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189 | pthread_cleanup_push(release_read_lock, &l->lock); |
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190 | |
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191 | /* Thread has read lock. */ |
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192 | release_read_lock_ran = FALSE; |
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193 | puts("cleanup pop for read"); |
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194 | pthread_cleanup_pop(1); |
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195 | |
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196 | if ( release_read_lock_ran == FALSE ) { |
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197 | puts( "release read lock did not run" ); |
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198 | rtems_test_exit(0); |
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199 | } |
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200 | return NULL; |
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201 | } |
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202 | |
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203 | void *WriterThread(void *arg) |
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204 | { |
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205 | lock_t *l = arg; |
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206 | |
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207 | puts("Lock for write"); |
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208 | lock_for_write(l); |
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209 | puts("cleanup push for write"); |
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210 | pthread_cleanup_push(release_write_lock, &l->lock); |
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211 | |
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212 | /* Thread has write lock. */ |
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213 | release_write_lock(&l->lock); |
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214 | |
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215 | /* do nothing */ |
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216 | puts("do nothing cleanup pop for write"); |
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217 | pthread_cleanup_pop(0); |
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218 | return NULL; |
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219 | } |
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220 | |
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221 | /* |
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222 | * main entry point to the test |
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223 | */ |
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224 | |
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225 | void *POSIX_Init( |
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226 | void *argument |
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227 | ) |
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228 | { |
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229 | pthread_attr_t attr; /* task attributes */ |
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230 | int status; |
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231 | lock_t l; |
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232 | |
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233 | puts( "\n\n*** POSIX CLEANUP TEST ***" ); |
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234 | |
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235 | /*************** INITIALIZE ***************/ |
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236 | initialize_lock_t(&l); |
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237 | if (pthread_attr_init(&attr) != 0) { |
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238 | perror ("Error in attribute init\n"); |
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239 | } |
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240 | |
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241 | /*************** CREATE THREADS ***************/ |
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242 | |
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243 | status = pthread_create(&ThreadIds[0], NULL, ReaderThread, &l); |
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244 | posix_service_failed( status, "pthread_create Reader" ); |
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245 | |
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246 | sleep(1); |
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247 | |
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248 | status = pthread_create(&ThreadIds[1], NULL, WriterThread, &l); |
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249 | posix_service_failed( status, "pthread_create Writer" ); |
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250 | |
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251 | sleep(1); |
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252 | |
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253 | /*************** END OF TEST *****************/ |
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254 | puts( "*** END OF POSIX CLEANUP TEST ***\n" ); |
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255 | rtems_test_exit(0); |
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256 | } |
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257 | |
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