src/simix/smx_synchro.c

   1 /*      $Id$     */
   2
   3 /* Copyright (c) 2007 Arnaud Legrand, Bruno Donnassolo.
   4    All rights reserved.                                          */
   5
   6 /* This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the license (GNU LGPL) which comes with this package. */
   8
   9 #include "private.h"
  10 #include "xbt/log.h"
  11
  12
  13 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_synchro, simix,
  14                                 "Logging specific to SIMIX (synchronization)");
  15
  16
  17 /****************************** Synchronization *******************************/
  18
  19 /*********************************** Mutex ************************************/
  20 smx_mutex_t SIMIX_mutex_init()
  21 {
  22         smx_mutex_t m = xbt_new0(s_smx_mutex_t,1);
  23         s_smx_process_t p; /* useful to initialize sleeping swag */
  24         /* structures initialization */
  25         m->using = 0;
  26         m->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
  27         return m;
  28 }
  29
  30 void SIMIX_mutex_lock(smx_mutex_t mutex)
  31 {
  32         smx_process_t self = SIMIX_process_self();
  33
  34         xbt_assert0((mutex != NULL), "Invalid parameters");
  35
  36         if (mutex->using) {
  37                 /* somebody using the mutex, block */
  38                 xbt_swag_insert(self, mutex->sleeping);
  39                 self->simdata->mutex = mutex;
  40                 /* wait for some process make the unlock and wake up me from mutex->sleeping */
  41                 xbt_context_yield();
  42                 /* verify if the process was suspended */
  43                 while (self->simdata->suspended) {
  44                         xbt_context_yield();
  45                 }
  46
  47                 self->simdata->mutex = NULL;
  48                 mutex->using = 1;
  49         }
  50         else {
  51                 /* mutex free */
  52                 mutex->using = 1;
  53         }
  54         return;
  55 }
  56
  57 /* return 1 if the process got the mutex, else 0. */
  58 int SIMIX_mutex_trylock(smx_mutex_t mutex)
  59 {
  60         xbt_assert0((mutex != NULL), "Invalid parameters");
  61
  62         if (mutex->using)
  63                 return 0;
  64         else {
  65                 mutex->using = 1;
  66                 return 1;
  67         }
  68 }
  69
  70 void SIMIX_mutex_unlock(smx_mutex_t mutex)
  71 {
  72         smx_process_t p;        /*process to wake up */
  73
  74         xbt_assert0((mutex != NULL), "Invalid parameters");
  75
  76         if (xbt_swag_size(mutex->sleeping) > 0) {
  77                 p = xbt_swag_extract(mutex->sleeping);
  78                 mutex->using = 0;
  79                 xbt_swag_insert(p, simix_global->process_to_run);
  80         }
  81         else {
  82                 /* nobody to wake up */
  83                 mutex->using = 0;
  84         }
  85         return;
  86 }
  87
  88 void SIMIX_mutex_destroy(smx_mutex_t mutex)
  89 {
  90         if ( mutex == NULL )
  91                 return ;
  92         else {
  93                 xbt_swag_free(mutex->sleeping);
  94                 xbt_free(mutex);
  95                 return ;
  96         }
  97 }
  98
  99 /******************************** Conditional *********************************/
 100 smx_cond_t SIMIX_cond_init()
 101 {
 102         smx_cond_t cond = xbt_new0(s_smx_cond_t,1);
 103         s_smx_process_t p;
 104
 105         cond->sleeping = xbt_swag_new(xbt_swag_offset(p,synchro_hookup));
 106         cond->actions = xbt_fifo_new();
 107         cond->mutex = NULL;
 108         return cond;
 109 }
 110
 111 void SIMIX_cond_signal(smx_cond_t cond)
 112 {
 113         xbt_assert0((cond != NULL), "Invalid parameters");
 114         smx_process_t proc = NULL;
 115
 116         if (xbt_swag_size(cond->sleeping) >= 1) {
 117                 proc = xbt_swag_extract(cond->sleeping);
 118                 xbt_swag_insert(proc, simix_global->process_to_run);
 119         }
 120
 121         return;
 122 }
 123
 124 void SIMIX_cond_wait(smx_cond_t cond,smx_mutex_t mutex)
 125 {
 126         smx_process_t self = SIMIX_process_self();
 127         smx_action_t act_sleep;
 128         xbt_assert0((mutex != NULL), "Invalid parameters");
 129
 130         cond->mutex = mutex;
 131
 132         SIMIX_mutex_unlock(mutex);
 133         /* create an action null only if there are no actions already on the condition, usefull if the host crashs */
 134         if (xbt_fifo_size(cond->actions) ==0 ) {
 135                 act_sleep = SIMIX_action_sleep(SIMIX_host_self(), -1);
 136                 SIMIX_register_action_to_condition(act_sleep,cond);
 137                 SIMIX_register_condition_to_action(act_sleep,cond);
 138                 __SIMIX_cond_wait(cond);
 139                 xbt_fifo_pop(act_sleep->cond_list);
 140                 SIMIX_action_destroy(act_sleep);
 141         }
 142         else {
 143                 __SIMIX_cond_wait(cond);
 144         }
 145         /* get the mutex again */
 146         self->simdata->mutex = cond->mutex;
 147         SIMIX_mutex_lock(cond->mutex);
 148
 149         return;
 150 }
 151
 152 void __SIMIX_cond_wait(smx_cond_t cond)
 153 {
 154         smx_process_t self = SIMIX_process_self();
 155         xbt_assert0((cond != NULL), "Invalid parameters");
 156
 157         /* process status */
 158         self->simdata->cond = cond;
 159
 160         xbt_swag_insert(self, cond->sleeping);
 161         xbt_context_yield();
 162         self->simdata->cond = NULL;
 163         while (self->simdata->suspended) {
 164                 xbt_context_yield();
 165         }
 166         return;
 167
 168 }
 169
 170 void SIMIX_cond_wait_timeout(smx_cond_t cond,smx_mutex_t mutex, double max_duration)
 171 {
 172         smx_process_t self = SIMIX_process_self();
 173         xbt_assert0((mutex != NULL), "Invalid parameters");
 174         smx_action_t act_sleep;
 175
 176         cond->mutex = mutex;
 177
 178         SIMIX_mutex_unlock(mutex);
 179         if (max_duration >=0) {
 180                 act_sleep = SIMIX_action_sleep(SIMIX_host_self(), max_duration);
 181                 SIMIX_register_action_to_condition(act_sleep,cond);
 182                 SIMIX_register_condition_to_action(act_sleep,cond);
 183         }
 184         __SIMIX_cond_wait(cond);
 185
 186         /* get the mutex again */
 187         self->simdata->mutex = cond->mutex;
 188         SIMIX_mutex_lock(cond->mutex);
 189
 190         return;
 191 }
 192
 193 void SIMIX_cond_broadcast(smx_cond_t cond)
 194 {
 195         xbt_assert0((cond != NULL), "Invalid parameters");
 196         smx_process_t proc = NULL;
 197         smx_process_t proc_next = NULL;
 198
 199         xbt_swag_foreach_safe(proc,proc_next,cond->sleeping) {
 200                 xbt_swag_remove(proc,cond->sleeping);
 201                 xbt_swag_insert(proc, simix_global->process_to_run);
 202         }
 203
 204         return;
 205 }
 206
 207 void SIMIX_cond_destroy(smx_cond_t cond)
 208 {
 209         if ( cond == NULL )
 210                 return ;
 211         else {
 212                 xbt_assert0( xbt_swag_size(cond->sleeping) == 0 , "Cannot destroy conditional");
 213                 xbt_swag_free(cond->sleeping);
 214                 xbt_fifo_free(cond->actions);
 215                 xbt_free(cond);
 216                 return;
 217         }
 218 }
 219
 220 void SIMIX_register_condition_to_action(smx_action_t action, smx_cond_t cond)
 221 {
 222         xbt_assert0( (action != NULL) && (cond != NULL), "Invalid parameters");
 223
 224         xbt_fifo_push(action->cond_list,cond);
 225 }
 226
 227