1 | /* |
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2 | * Copyright 2010, Alin Rus <alin.codejunkie@gmail.com> |
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3 | * |
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4 | * The license and distribution terms for this file may be |
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5 | * found in the file LICENSE in this distribution or at |
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6 | * http://www.rtems.com/license/LICENSE. |
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7 | * |
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8 | * $Id$ |
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9 | */ |
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10 | |
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11 | #include <pthread.h> |
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12 | #include <stdlib.h> |
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13 | #include <unistd.h> |
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14 | #include <time.h> |
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15 | #include <rtems/posix/aio_misc.h> |
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16 | |
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17 | static void *rtems_aio_handle (void *arg); |
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18 | |
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19 | rtems_aio_queue aio_request_queue; |
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20 | |
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21 | /* |
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22 | * rtems_aio_init |
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23 | * |
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24 | * Initialize the request queue for aio |
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25 | * |
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26 | * Input parameters: |
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27 | * NONE |
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28 | * |
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29 | * Output parameters: |
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30 | * 0 - if initialization succeeded |
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31 | */ |
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32 | |
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33 | int |
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34 | rtems_aio_init (void) |
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35 | { |
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36 | int result = 0; |
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37 | |
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38 | result = pthread_attr_init (&aio_request_queue.attr); |
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39 | if (result != 0) |
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40 | return result; |
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41 | |
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42 | result = |
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43 | pthread_attr_setdetachstate (&aio_request_queue.attr, |
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44 | PTHREAD_CREATE_DETACHED); |
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45 | if (result != 0) |
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46 | pthread_attr_destroy (&aio_request_queue.attr); |
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47 | |
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48 | |
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49 | result = pthread_mutex_init (&aio_request_queue.mutex, NULL); |
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50 | if (result != 0) |
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51 | pthread_attr_destroy (&aio_request_queue.attr); |
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52 | |
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53 | |
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54 | result = pthread_cond_init (&aio_request_queue.new_req, NULL); |
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55 | if (result != 0) { |
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56 | pthread_mutex_destroy (&aio_request_queue.mutex); |
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57 | pthread_attr_destroy (&aio_request_queue.attr); |
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58 | } |
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59 | |
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60 | rtems_chain_initialize_empty (&aio_request_queue.work_req); |
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61 | rtems_chain_initialize_empty (&aio_request_queue.idle_req); |
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62 | |
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63 | aio_request_queue.active_threads = 0; |
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64 | aio_request_queue.idle_threads = 0; |
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65 | aio_request_queue.initialized = AIO_QUEUE_INITIALIZED; |
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66 | |
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67 | return result; |
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68 | } |
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69 | |
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70 | /* |
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71 | * rtems_aio_search_fd |
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72 | * |
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73 | * Search and create chain of requests for given FD |
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74 | * |
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75 | * Input parameters: |
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76 | * chain - chain of FD chains |
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77 | * fildes - file descriptor to search |
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78 | * create - if 1 search and create |
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79 | * - if 0 just search |
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80 | * |
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81 | * Output parameters: |
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82 | * r_chain - NULL if create == 0 and there is |
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83 | * no chain for given fildes |
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84 | * - pointer to chain is there exists |
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85 | * a chain for given fildes |
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86 | * - pointer to newly create chain if |
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87 | * create == 1 |
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88 | * |
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89 | */ |
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90 | |
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91 | rtems_aio_request_chain * |
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92 | rtems_aio_search_fd (rtems_chain_control *chain, int fildes, int create) |
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93 | { |
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94 | rtems_aio_request_chain *r_chain; |
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95 | rtems_chain_node *node; |
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96 | |
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97 | node = chain->first; |
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98 | r_chain = (rtems_aio_request_chain *) node; |
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99 | |
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100 | while (r_chain->fildes < fildes && !rtems_chain_is_tail (chain, node)) { |
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101 | node = node->next; |
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102 | r_chain = (rtems_aio_request_chain *) node; |
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103 | } |
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104 | |
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105 | if (r_chain->fildes == fildes) |
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106 | r_chain->new_fd = 0; |
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107 | else { |
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108 | if (create == 0) |
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109 | r_chain = NULL; |
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110 | else { |
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111 | r_chain = malloc (sizeof (rtems_aio_request_chain)); |
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112 | rtems_chain_initialize_empty (&r_chain->perfd); |
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113 | |
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114 | if (rtems_chain_is_empty (chain)) |
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115 | rtems_chain_prepend (chain, &r_chain->next_fd); |
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116 | else |
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117 | rtems_chain_insert (node->previous, &r_chain->next_fd); |
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118 | |
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119 | r_chain->new_fd = 1; |
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120 | } |
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121 | } |
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122 | return r_chain; |
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123 | } |
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124 | |
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125 | /* |
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126 | * rtems_aio_insert_prio |
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127 | * |
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128 | * Add request to given FD chain. The chain is ordered |
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129 | * by priority |
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130 | * |
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131 | * Input parameters: |
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132 | * chain - chain of requests for a given FD |
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133 | * req - request (see aio_misc.h) |
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134 | * |
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135 | * Output parameters: |
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136 | * NONE |
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137 | */ |
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138 | |
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139 | void |
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140 | rtems_aio_insert_prio (rtems_chain_control *chain, rtems_aio_request *req) |
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141 | { |
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142 | rtems_chain_node *node; |
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143 | |
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144 | AIO_printf ("FD exists \n"); |
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145 | node = chain->first; |
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146 | |
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147 | if (rtems_chain_is_empty (chain)) { |
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148 | AIO_printf ("First in chain \n"); |
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149 | rtems_chain_prepend (chain, &req->next_prio); |
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150 | } else { |
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151 | AIO_printf ("Add by priority \n"); |
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152 | int prio = ((rtems_aio_request *) node)->aiocbp->aio_reqprio; |
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153 | |
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154 | while (req->aiocbp->aio_reqprio > prio && |
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155 | !rtems_chain_is_tail (chain, node)) { |
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156 | node = node->next; |
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157 | prio = ((rtems_aio_request *) node)->aiocbp->aio_reqprio; |
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158 | } |
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159 | |
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160 | rtems_chain_insert (node->previous, &req->next_prio); |
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161 | |
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162 | } |
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163 | } |
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164 | |
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165 | /* |
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166 | * rtems_aio_remove_fd |
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167 | * |
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168 | * Removes all the requests in a fd chain |
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169 | * |
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170 | * Input parameters: |
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171 | * r_chain - pointer to the fd chain request |
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172 | * |
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173 | * Output parameters: |
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174 | * NONE |
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175 | */ |
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176 | |
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177 | void rtems_aio_remove_fd (rtems_aio_request_chain *r_chain) |
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178 | { |
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179 | rtems_chain_control *chain; |
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180 | rtems_chain_node *node; |
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181 | |
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182 | chain = &r_chain->perfd; |
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183 | node = chain->first; |
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184 | |
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185 | while (!rtems_chain_is_tail (chain, node)) |
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186 | { |
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187 | rtems_chain_extract (node); |
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188 | rtems_aio_request *req = (rtems_aio_request *) node; |
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189 | req->aiocbp->error_code = ECANCELED; |
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190 | req->aiocbp->return_value = -1; |
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191 | free (req); |
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192 | } |
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193 | } |
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194 | |
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195 | /* |
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196 | * rtems_aio_remove_req |
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197 | * |
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198 | * Removes request from given chain |
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199 | * |
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200 | * Input parameters: |
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201 | * chain - pointer to fd chain which may contain |
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202 | * the request |
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203 | * aiocbp - pointer to request that needs to be |
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204 | * canceled |
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205 | * |
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206 | * Output parameters: |
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207 | * AIO_NOTCANCELED - if request was not canceled |
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208 | * AIO_CANCELED - if request was canceled |
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209 | */ |
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210 | |
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211 | int rtems_aio_remove_req (rtems_chain_control *chain, struct aiocb *aiocbp) |
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212 | { |
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213 | rtems_chain_node *node = chain->first; |
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214 | rtems_aio_request *current; |
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215 | |
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216 | current = (rtems_aio_request *) node; |
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217 | |
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218 | while (!rtems_chain_is_tail (chain, node) && current->aiocbp != aiocbp) { |
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219 | node = node->next; |
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220 | current = (rtems_aio_request *) node; |
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221 | } |
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222 | |
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223 | if (rtems_chain_is_tail (chain, node)) |
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224 | return AIO_NOTCANCELED; |
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225 | else |
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226 | { |
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227 | rtems_chain_extract (node); |
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228 | current->aiocbp->error_code = ECANCELED; |
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229 | current->aiocbp->return_value = -1; |
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230 | free (current); |
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231 | } |
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232 | |
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233 | return AIO_CANCELED; |
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234 | } |
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235 | |
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236 | /* |
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237 | * rtems_aio_enqueue |
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238 | * |
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239 | * Enqueue requests, and creates threads to process them |
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240 | * |
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241 | * Input parameters: |
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242 | * req - see aio_misc.h |
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243 | * |
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244 | * Output parameters: |
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245 | * 0 - if request was added to queue |
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246 | * errno - otherwise |
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247 | */ |
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248 | |
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249 | int |
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250 | rtems_aio_enqueue (rtems_aio_request *req) |
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251 | { |
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252 | |
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253 | rtems_aio_request_chain *r_chain; |
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254 | rtems_chain_control *chain; |
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255 | pthread_t thid; |
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256 | int result, policy; |
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257 | struct sched_param param; |
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258 | |
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259 | /* The queue should be initialized */ |
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260 | AIO_assert (aio_request_queue.initialized != AIO_QUEUE_INITIALIZED); |
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261 | |
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262 | result = pthread_mutex_lock (&aio_request_queue.mutex); |
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263 | if (result != 0) { |
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264 | free (req); |
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265 | return result; |
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266 | } |
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267 | |
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268 | /* _POSIX_PRIORITIZED_IO and _POSIX_PRIORITY_SCHEDULING are defined, |
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269 | we can use aio_reqprio to lower the priority of the request */ |
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270 | pthread_getschedparam (pthread_self(), &policy, ¶m); |
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271 | |
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272 | req->caller_thread = pthread_self (); |
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273 | req->priority = param.sched_priority - req->aiocbp->aio_reqprio; |
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274 | req->policy = policy; |
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275 | req->aiocbp->error_code = EINPROGRESS; |
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276 | req->aiocbp->return_value = 0; |
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277 | |
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278 | if ((aio_request_queue.idle_threads == 0) && |
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279 | aio_request_queue.active_threads < AIO_MAX_THREADS) |
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280 | /* we still have empty places on the active_threads chain */ |
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281 | { |
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282 | chain = &aio_request_queue.work_req; |
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283 | r_chain = rtems_aio_search_fd (chain, req->aiocbp->aio_fildes, 1); |
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284 | |
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285 | if (r_chain->new_fd == 1) { |
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286 | rtems_chain_prepend (&r_chain->perfd, &req->next_prio); |
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287 | r_chain->new_fd = 0; |
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288 | pthread_mutex_init (&r_chain->mutex, NULL); |
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289 | pthread_cond_init (&r_chain->cond, NULL); |
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290 | |
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291 | AIO_printf ("New thread"); |
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292 | result = pthread_create (&thid, &aio_request_queue.attr, |
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293 | rtems_aio_handle, (void *) r_chain); |
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294 | if (result != 0) { |
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295 | pthread_mutex_unlock (&aio_request_queue.mutex); |
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296 | return result; |
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297 | } |
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298 | ++aio_request_queue.active_threads; |
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299 | } |
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300 | else { |
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301 | /* put request in the fd chain it belongs to */ |
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302 | pthread_mutex_lock (&r_chain->mutex); |
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303 | rtems_aio_insert_prio (&r_chain->perfd, req); |
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304 | pthread_cond_signal (&r_chain->cond); |
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305 | pthread_mutex_unlock (&r_chain->mutex); |
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306 | } |
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307 | } |
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308 | else |
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309 | { |
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310 | /* the maximum number of threads has been already created |
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311 | even though some of them might be idle. |
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312 | The request belongs to one of the active fd chain */ |
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313 | r_chain = rtems_aio_search_fd (&aio_request_queue.work_req, |
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314 | req->aiocbp->aio_fildes, 0); |
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315 | if (r_chain != NULL) |
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316 | { |
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317 | pthread_mutex_lock (&r_chain->mutex); |
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318 | rtems_aio_insert_prio (&r_chain->perfd, req); |
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319 | pthread_cond_signal (&r_chain->cond); |
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320 | pthread_mutex_unlock (&r_chain->mutex); |
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321 | |
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322 | } else { |
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323 | |
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324 | /* or to the idle chain */ |
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325 | chain = &aio_request_queue.idle_req; |
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326 | r_chain = rtems_aio_search_fd (chain, req->aiocbp->aio_fildes, 1); |
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327 | |
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328 | if (r_chain->new_fd == 1) { |
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329 | /* If this is a new fd chain we signal the idle threads that |
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330 | might be waiting for requests */ |
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331 | rtems_chain_prepend (&r_chain->perfd, &req->next_prio); |
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332 | r_chain->new_fd = 0; |
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333 | pthread_mutex_init (&r_chain->mutex, NULL); |
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334 | pthread_cond_init (&r_chain->cond, NULL); |
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335 | pthread_cond_signal (&aio_request_queue.new_req); |
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336 | } else |
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337 | /* just insert the request in the existing fd chain */ |
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338 | rtems_aio_insert_prio (&r_chain->perfd, req); |
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339 | } |
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340 | } |
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341 | |
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342 | pthread_mutex_unlock (&aio_request_queue.mutex); |
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343 | return 0; |
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344 | } |
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345 | |
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346 | /* |
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347 | * rtems_aio_handle |
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348 | * |
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349 | * Thread processing requests |
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350 | * |
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351 | * Input parameters: |
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352 | * arg - the chain for the fd to be worked on |
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353 | * |
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354 | * Output parameters: |
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355 | * NULL - if error |
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356 | */ |
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357 | |
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358 | static void * |
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359 | rtems_aio_handle (void *arg) |
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360 | { |
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361 | |
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362 | rtems_aio_request_chain *r_chain = arg; |
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363 | rtems_aio_request *req; |
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364 | rtems_chain_control *chain; |
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365 | rtems_chain_node *node; |
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366 | int result, policy; |
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367 | struct sched_param param; |
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368 | |
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369 | AIO_printf ("Thread started\n"); |
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370 | |
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371 | while (1) { |
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372 | |
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373 | /* acquire the mutex of the current fd chain. |
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374 | we don't need to lock the queue mutex since we can |
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375 | add requests to idle fd chains or even active ones |
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376 | if the working request has been extracted from the |
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377 | chain */ |
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378 | result = pthread_mutex_lock (&r_chain->mutex); |
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379 | if (result != 0) |
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380 | return NULL; |
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381 | |
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382 | chain = &r_chain->perfd; |
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383 | |
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384 | /* If the locked chain is not empty, take the first |
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385 | request extract it, unlock the chain and process |
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386 | the request, in this way the user can supply more |
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387 | requests to this fd chain */ |
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388 | if (!rtems_chain_is_empty (chain)) { |
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389 | |
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390 | node = chain->first; |
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391 | req = (rtems_aio_request *) node; |
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392 | |
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393 | /* See _POSIX_PRIORITIZE_IO and _POSIX_PRIORITY_SCHEDULING |
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394 | discussion in rtems_aio_enqueue () */ |
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395 | pthread_getschedparam (pthread_self(), &policy, ¶m); |
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396 | param.sched_priority = req->priority; |
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397 | pthread_setschedparam (pthread_self(), req->policy, ¶m); |
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398 | |
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399 | rtems_chain_extract (node); |
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400 | |
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401 | pthread_mutex_unlock (&r_chain->mutex); |
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402 | |
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403 | switch (req->aiocbp->aio_lio_opcode) { |
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404 | case LIO_READ: |
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405 | result = pread (req->aiocbp->aio_fildes, |
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406 | (void *) req->aiocbp->aio_buf, |
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407 | req->aiocbp->aio_nbytes, req->aiocbp->aio_offset); |
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408 | break; |
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409 | |
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410 | case LIO_WRITE: |
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411 | result = pwrite (req->aiocbp->aio_fildes, |
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412 | (void *) req->aiocbp->aio_buf, |
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413 | req->aiocbp->aio_nbytes, req->aiocbp->aio_offset); |
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414 | break; |
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415 | |
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416 | case LIO_SYNC: |
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417 | result = fsync (req->aiocbp->aio_fildes); |
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418 | break; |
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419 | |
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420 | default: |
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421 | result = -1; |
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422 | } |
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423 | if (result == -1) { |
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424 | req->aiocbp->return_value = -1; |
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425 | req->aiocbp->error_code = errno; |
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426 | } else { |
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427 | req->aiocbp->return_value = result; |
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428 | req->aiocbp->error_code = 0; |
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429 | } |
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430 | |
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431 | // notification needed for lio |
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432 | |
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433 | } else { |
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434 | /* If the fd chain is empty we unlock the fd chain |
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435 | and we lock the queue chain, this will ensure that |
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436 | we have at most one request comming to our fd chain |
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437 | when we check. |
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438 | |
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439 | If there was no request added sleep for 3 seconds and |
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440 | wait for a signal on chain, this will unlock the queue. |
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441 | The fd chain is already unlocked */ |
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442 | |
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443 | struct timespec timeout; |
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444 | |
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445 | pthread_mutex_unlock (&r_chain->mutex); |
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446 | pthread_mutex_lock (&aio_request_queue.mutex); |
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447 | if (rtems_chain_is_empty (chain)) |
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448 | { |
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449 | clock_gettime (CLOCK_REALTIME, &timeout); |
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450 | timeout.tv_sec += 3; |
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451 | timeout.tv_nsec = 0; |
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452 | result = pthread_cond_timedwait (&r_chain->cond, |
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453 | &aio_request_queue.mutex, &timeout); |
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454 | |
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455 | /* If no requests were added to the chain we delete the fd chain from |
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456 | the queue and start working with idle fd chains */ |
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457 | if (result == ETIMEDOUT) { |
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458 | rtems_chain_extract (&r_chain->next_fd); |
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459 | pthread_mutex_destroy (&r_chain->mutex); |
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460 | pthread_cond_destroy (&r_chain->cond); |
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461 | free (r_chain); |
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462 | |
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463 | /* If the idle chain is empty sleep for 3 seconds and wait for a |
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464 | signal. The thread now becomes idle. */ |
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465 | if (rtems_chain_is_empty (&aio_request_queue.idle_req)) { |
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466 | ++aio_request_queue.idle_threads; |
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467 | clock_gettime (CLOCK_REALTIME, &timeout); |
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468 | timeout.tv_sec += 3; |
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469 | timeout.tv_nsec = 0; |
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470 | result = pthread_cond_timedwait (&aio_request_queue.new_req, |
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471 | &aio_request_queue.mutex, |
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472 | &timeout); |
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473 | |
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474 | /* If no new fd chain was added in the idle requests |
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475 | then this thread is finished */ |
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476 | if (result == ETIMEDOUT) { |
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477 | pthread_mutex_unlock (&aio_request_queue.mutex); |
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478 | return NULL; |
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479 | } |
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480 | |
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481 | /* Otherwise move this chain to the working chain and |
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482 | start the loop all over again */ |
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483 | --aio_request_queue.idle_threads; |
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484 | node = aio_request_queue.idle_req.first; |
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485 | rtems_chain_extract (node); |
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486 | r_chain = rtems_aio_search_fd (&aio_request_queue.work_req, |
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487 | ((rtems_aio_request_chain *)node)->fildes, |
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488 | 1); |
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489 | r_chain->new_fd = 0; |
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490 | pthread_mutex_init (&r_chain->mutex, NULL); |
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491 | pthread_cond_init (&r_chain->cond, NULL); |
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492 | |
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493 | r_chain->perfd = ((rtems_aio_request_chain *)node)->perfd; |
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494 | } |
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495 | else |
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496 | /* If there was a request added in the initial fd chain then release |
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497 | the mutex and process it */ |
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498 | pthread_mutex_unlock (&aio_request_queue.mutex); |
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499 | } |
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500 | } |
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501 | } |
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502 | } |
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503 | |
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504 | |
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505 | AIO_printf ("Thread finished\n"); |
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506 | return NULL; |
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507 | } |
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