lwip/core/sys.c

   1 /*
   2  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without modification,
   6  * are permitted provided that the following conditions are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright notice,
   9  *    this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright notice,
  11  *    this list of conditions and the following disclaimer in the documentation
  12  *    and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  19  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  21  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  24  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  25  * OF SUCH DAMAGE.
  26  *
  27  * This file is part of the lwIP TCP/IP stack.
  28  *
  29  * Author: Adam Dunkels <adam@sics.se>
  30  *
  31  */
  32
  33 #include "lwip/sys.h"
  34 #include "lwip/opt.h"
  35 #include "lwip/def.h"
  36 #include "lwip/memp.h"
  37
  38 #if (NO_SYS == 0)
  39
  40 struct sswt_cb
  41 {
  42     s16_t timeflag;
  43     sys_sem_t *psem;
  44 };
  45
  46
  47
  48 void
  49 sys_mbox_fetch(sys_mbox_t mbox, void **msg)
  50 {
  51   u32_t time;
  52   struct sys_timeouts *timeouts;
  53   struct sys_timeout *tmptimeout;
  54   sys_timeout_handler h;
  55   void *arg;
  56
  57
  58  again:
  59   timeouts = sys_arch_timeouts();
  60
  61   if (!timeouts || !timeouts->next) {
  62     sys_arch_mbox_fetch(mbox, msg, 0);
  63   } else {
  64     if (timeouts->next->time > 0) {
  65       time = sys_arch_mbox_fetch(mbox, msg, timeouts->next->time);
  66     } else {
  67       time = SYS_ARCH_TIMEOUT;
  68     }
  69
  70     if (time == SYS_ARCH_TIMEOUT) {
  71       /* If time == SYS_ARCH_TIMEOUT, a timeout occured before a message
  72    could be fetched. We should now call the timeout handler and
  73    deallocate the memory allocated for the timeout. */
  74       tmptimeout = timeouts->next;
  75       timeouts->next = tmptimeout->next;
  76       h = tmptimeout->h;
  77       arg = tmptimeout->arg;
  78       memp_free(MEMP_SYS_TIMEOUT, tmptimeout);
  79       if (h != NULL) {
  80         LWIP_DEBUGF(SYS_DEBUG, ("smf calling h=%p(%p)\n", (void *)h, (void *)arg));
  81         h(arg);
  82       }
  83
  84       /* We try again to fetch a message from the mbox. */
  85       goto again;
  86     } else {
  87       /* If time != SYS_ARCH_TIMEOUT, a message was received before the timeout
  88    occured. The time variable is set to the number of
  89    milliseconds we waited for the message. */
  90       if (time <= timeouts->next->time) {
  91   timeouts->next->time -= time;
  92       } else {
  93   timeouts->next->time = 0;
  94       }
  95     }
  96
  97   }
  98 }
  99
 100 void
 101 sys_sem_wait(sys_sem_t sem)
 102 {
 103   u32_t time;
 104   struct sys_timeouts *timeouts;
 105   struct sys_timeout *tmptimeout;
 106   sys_timeout_handler h;
 107   void *arg;
 108
 109   /*  while (sys_arch_sem_wait(sem, 1000) == 0);
 110       return;*/
 111
 112  again:
 113
 114   timeouts = sys_arch_timeouts();
 115
 116   if (!timeouts || !timeouts->next) {
 117     sys_arch_sem_wait(sem, 0);
 118   } else {
 119     if (timeouts->next->time > 0) {
 120       time = sys_arch_sem_wait(sem, timeouts->next->time);
 121     } else {
 122       time = SYS_ARCH_TIMEOUT;
 123     }
 124
 125     if (time == SYS_ARCH_TIMEOUT) {
 126       /* If time == SYS_ARCH_TIMEOUT, a timeout occured before a message
 127    could be fetched. We should now call the timeout handler and
 128    deallocate the memory allocated for the timeout. */
 129       tmptimeout = timeouts->next;
 130       timeouts->next = tmptimeout->next;
 131       h = tmptimeout->h;
 132       arg = tmptimeout->arg;
 133       memp_free(MEMP_SYS_TIMEOUT, tmptimeout);
 134       if (h != NULL) {
 135         LWIP_DEBUGF(SYS_DEBUG, ("ssw h=%p(%p)\n", (void *)h, (void *)arg));
 136         h(arg);
 137       }
 138
 139
 140       /* We try again to fetch a message from the mbox. */
 141       goto again;
 142     } else {
 143       /* If time != SYS_ARCH_TIMEOUT, a message was received before the timeout
 144    occured. The time variable is set to the number of
 145    milliseconds we waited for the message. */
 146       if (time <= timeouts->next->time) {
 147   timeouts->next->time -= time;
 148       } else {
 149   timeouts->next->time = 0;
 150       }
 151     }
 152
 153   }
 154 }
 155
 156 void
 157 sys_timeout(u32_t msecs, sys_timeout_handler h, void *arg)
 158 {
 159   struct sys_timeouts *timeouts;
 160   struct sys_timeout *timeout, *t;
 161
 162   timeout = memp_malloc(MEMP_SYS_TIMEOUT);
 163   if (timeout == NULL) {
 164     return;
 165   }
 166   timeout->next = NULL;
 167   timeout->h = h;
 168   timeout->arg = arg;
 169   timeout->time = msecs;
 170
 171   timeouts = sys_arch_timeouts();
 172
 173   LWIP_DEBUGF(SYS_DEBUG, ("sys_timeout: %p msecs=%"U32_F" h=%p arg=%p\n",
 174     (void *)timeout, msecs, (void *)h, (void *)arg));
 175
 176   LWIP_ASSERT("sys_timeout: timeouts != NULL", timeouts != NULL);
 177
 178   if (timeouts->next == NULL) {
 179     timeouts->next = timeout;
 180     return;
 181   }
 182
 183   if (timeouts->next->time > msecs) {
 184     timeouts->next->time -= msecs;
 185     timeout->next = timeouts->next;
 186     timeouts->next = timeout;
 187   } else {
 188     for(t = timeouts->next; t != NULL; t = t->next) {
 189       timeout->time -= t->time;
 190       if (t->next == NULL || t->next->time > timeout->time) {
 191         if (t->next != NULL) {
 192           t->next->time -= timeout->time;
 193         }
 194         timeout->next = t->next;
 195         t->next = timeout;
 196         break;
 197       }
 198     }
 199   }
 200
 201 }
 202
 203 /* Go through timeout list (for this task only) and remove the first matching entry,
 204    even though the timeout has not triggered yet.
 205 */
 206
 207 void
 208 sys_untimeout(sys_timeout_handler h, void *arg)
 209 {
 210     struct sys_timeouts *timeouts;
 211     struct sys_timeout *prev_t, *t;
 212
 213     timeouts = sys_arch_timeouts();
 214
 215     if (timeouts->next == NULL)
 216         return;
 217
 218     for (t = timeouts->next, prev_t = NULL; t != NULL; prev_t = t, t = t->next)
 219     {
 220         if ((t->h == h) && (t->arg == arg))
 221         {
 222             /* We have a match */
 223             /* Unlink from previous in list */
 224             if (prev_t == NULL)
 225                 timeouts->next = t->next;
 226             else
 227                 prev_t->next = t->next;
 228             /* If not the last one, add time of this one back to next */
 229             if (t->next != NULL)
 230                 t->next->time += t->time;
 231             memp_free(MEMP_SYS_TIMEOUT, t);
 232             return;
 233         }
 234     }
 235     return;
 236 }
 237
 238
 239
 240
 241
 242 static void
 243 sswt_handler(void *arg)
 244 {
 245     struct sswt_cb *sswt_cb = (struct sswt_cb *) arg;
 246
 247     /* Timeout. Set flag to TRUE and signal semaphore */
 248     sswt_cb->timeflag = 1;
 249     sys_sem_signal(*(sswt_cb->psem));
 250 }
 251
 252 /* Wait for a semaphore with timeout (specified in ms) */
 253 /* timeout = 0: wait forever */
 254 /* Returns 0 on timeout. 1 otherwise */
 255
 256 int
 257 sys_sem_wait_timeout(sys_sem_t sem, u32_t timeout)
 258 {
 259     struct sswt_cb sswt_cb;
 260
 261     sswt_cb.psem = &sem;
 262     sswt_cb.timeflag = 0;
 263
 264     /* If timeout is zero, then just wait forever */
 265     if (timeout > 0)
 266         /* Create a timer and pass it the address of our flag */
 267         sys_timeout(timeout, sswt_handler, &sswt_cb);
 268     sys_sem_wait(sem);
 269     /* Was it a timeout? */
 270     if (sswt_cb.timeflag)
 271     {
 272         /* timeout */
 273         return 0;
 274     } else {
 275         /* Not a timeout. Remove timeout entry */
 276         sys_untimeout(sswt_handler, &sswt_cb);
 277         return 1;
 278     }
 279
 280 }
 281
 282
 283 void
 284 sys_msleep(u32_t ms)
 285 {
 286   sys_sem_t delaysem = sys_sem_new(0);
 287
 288   sys_sem_wait_timeout(delaysem, ms);
 289
 290   sys_sem_free(delaysem);
 291 }
 292
 293
 294 #endif /* NO_SYS */