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         xbt_assert0((mutex != NULL), "Invalid parameters");
  34
  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                 self->simdata->mutex = NULL;
  43
  44                 /* verify if the process was suspended */
  45                 while (self->simdata->suspended) {
  46                         xbt_context_yield();
  47                 }
  48
  49                 mutex->using = 1;
  50         }
  51         else {
  52                 /* mutex free */
  53                 mutex->using = 1;
  54         }
  55         return;
  56 }
  57
  58 /* return 1 if the process got the mutex, else 0. */
  59 int SIMIX_mutex_trylock(smx_mutex_t mutex)
  60 {
  61         xbt_assert0((mutex != NULL), "Invalid parameters");
  62
  63         if (mutex->using)
  64                 return 0;
  65         else {
  66                 mutex->using = 1;
  67                 return 1;
  68         }
  69 }
  70
  71 void SIMIX_mutex_unlock(smx_mutex_t mutex)
  72 {
  73         smx_process_t p;        /*process to wake up */
  74
  75         xbt_assert0((mutex != NULL), "Invalid parameters");
  76
  77         if (xbt_swag_size(mutex->sleeping) > 0) {
  78                 p = xbt_swag_extract(mutex->sleeping);
  79                 mutex->using = 0;
  80                 xbt_swag_insert(p, simix_global->process_to_run);
  81         }
  82         else {
  83                 /* nobody to wake up */
  84                 mutex->using = 0;
  85         }
  86         return;
  87 }
  88
  89 void SIMIX_mutex_destroy(smx_mutex_t mutex)
  90 {
  91         if ( mutex == NULL )
  92                 return ;
  93         else {
  94                 xbt_swag_free(mutex->sleeping);
  95                 xbt_free(mutex);
  96                 return ;
  97         }
  98 }
  99
 100 /******************************** Conditional *********************************/
 101 smx_cond_t SIMIX_cond_init()
 102 {
 103         smx_cond_t cond = xbt_new0(s_smx_cond_t,1);
 104         s_smx_process_t p;
 105
 106         cond->sleeping = xbt_swag_new(xbt_swag_offset(p,synchro_hookup));
 107         cond->actions = xbt_fifo_new();
 108         cond->mutex = NULL;
 109         return cond;
 110 }
 111
 112 void SIMIX_cond_signal(smx_cond_t cond)
 113 {
 114         xbt_assert0((cond != NULL), "Invalid parameters");
 115         smx_process_t proc = NULL;
 116
 117         if (xbt_swag_size(cond->sleeping) >= 1) {
 118                 proc = xbt_swag_extract(cond->sleeping);
 119                 xbt_swag_insert(proc, simix_global->process_to_run);
 120         }
 121
 122         return;
 123 }
 124
 125 void SIMIX_cond_wait(smx_cond_t cond,smx_mutex_t mutex)
 126 {
 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         SIMIX_mutex_lock(cond->mutex);
 147
 148         return;
 149 }
 150
 151 void __SIMIX_cond_wait(smx_cond_t cond)
 152 {
 153         smx_process_t self = SIMIX_process_self();
 154         xbt_assert0((cond != NULL), "Invalid parameters");
 155
 156         /* process status */
 157
 158         self->simdata->cond = cond;
 159         xbt_swag_insert(self, cond->sleeping);
 160         xbt_context_yield();
 161         self->simdata->cond = NULL;
 162         while (self->simdata->suspended) {
 163                 xbt_context_yield();
 164         }
 165         return;
 166
 167 }
 168
 169 void SIMIX_cond_wait_timeout(smx_cond_t cond,smx_mutex_t mutex, double max_duration)
 170 {
 171         xbt_assert0((mutex != NULL), "Invalid parameters");
 172         smx_action_t act_sleep;
 173
 174         cond->mutex = mutex;
 175
 176         SIMIX_mutex_unlock(mutex);
 177         if (max_duration >=0) {
 178                 act_sleep = SIMIX_action_sleep(SIMIX_host_self(), max_duration);
 179                 SIMIX_register_action_to_condition(act_sleep,cond);
 180                 SIMIX_register_condition_to_action(act_sleep,cond);
 181         }
 182         __SIMIX_cond_wait(cond);
 183
 184         /* get the mutex again */
 185         SIMIX_mutex_lock(cond->mutex);
 186
 187         return;
 188 }
 189
 190 void SIMIX_cond_broadcast(smx_cond_t cond)
 191 {
 192         xbt_assert0((cond != NULL), "Invalid parameters");
 193         smx_process_t proc = NULL;
 194         smx_process_t proc_next = NULL;
 195
 196         xbt_swag_foreach_safe(proc,proc_next,cond->sleeping) {
 197                 xbt_swag_remove(proc,cond->sleeping);
 198                 xbt_swag_insert(proc, simix_global->process_to_run);
 199         }
 200
 201         return;
 202 }
 203
 204 void SIMIX_cond_destroy(smx_cond_t cond)
 205 {
 206         if ( cond == NULL )
 207                 return ;
 208         else {
 209                 xbt_assert0( xbt_swag_size(cond->sleeping) == 0 , "Cannot destroy conditional");
 210                 xbt_swag_free(cond->sleeping);
 211                 xbt_fifo_free(cond->actions);
 212                 xbt_free(cond);
 213                 return;
 214         }
 215 }
 216
 217 void SIMIX_register_condition_to_action(smx_action_t action, smx_cond_t cond)
 218 {
 219         xbt_assert0( (action != NULL) && (cond != NULL), "Invalid parameters");
 220
 221         xbt_fifo_push(action->cond_list,cond);
 222 }
 223
 224