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lwip_timeouts.c
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00001 /** 00002 * @file 00003 * Stack-internal timers implementation. 00004 * This file includes timer callbacks for stack-internal timers as well as 00005 * functions to set up or stop timers and check for expired timers. 00006 * 00007 */ 00008 00009 /* 00010 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 00011 * All rights reserved. 00012 * 00013 * Redistribution and use in source and binary forms, with or without modification, 00014 * are permitted provided that the following conditions are met: 00015 * 00016 * 1. Redistributions of source code must retain the above copyright notice, 00017 * this list of conditions and the following disclaimer. 00018 * 2. Redistributions in binary form must reproduce the above copyright notice, 00019 * this list of conditions and the following disclaimer in the documentation 00020 * and/or other materials provided with the distribution. 00021 * 3. The name of the author may not be used to endorse or promote products 00022 * derived from this software without specific prior written permission. 00023 * 00024 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00025 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00026 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00027 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00028 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00029 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00030 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00031 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00032 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00033 * OF SUCH DAMAGE. 00034 * 00035 * This file is part of the lwIP TCP/IP stack. 00036 * 00037 * Author: Adam Dunkels <adam@sics.se> 00038 * Simon Goldschmidt 00039 * 00040 */ 00041 00042 #include "lwip/opt.h" 00043 00044 #include "lwip/timeouts.h" 00045 #include "lwip/priv/tcp_priv.h" 00046 00047 #include "lwip/def.h" 00048 #include "lwip/memp.h" 00049 #include "lwip/priv/tcpip_priv.h" 00050 00051 #include "lwip/ip4_frag.h" 00052 #include "lwip/etharp.h" 00053 #include "lwip/dhcp.h" 00054 #include "lwip/autoip.h" 00055 #include "lwip/igmp.h" 00056 #include "lwip/dns.h" 00057 #include "lwip/nd6.h" 00058 #include "lwip/ip6_frag.h" 00059 #include "lwip/mld6.h" 00060 #include "lwip/sys.h" 00061 #include "lwip/pbuf.h" 00062 00063 #if LWIP_DEBUG_TIMERNAMES 00064 #define HANDLER(x) x, #x 00065 #else /* LWIP_DEBUG_TIMERNAMES */ 00066 #define HANDLER(x) x 00067 #endif /* LWIP_DEBUG_TIMERNAMES */ 00068 00069 /** This array contains all stack-internal cyclic timers. To get the number of 00070 * timers, use LWIP_ARRAYSIZE() */ 00071 const struct lwip_cyclic_timer lwip_cyclic_timers[] = { 00072 #if LWIP_TCP 00073 /* The TCP timer is a special case: it does not have to run always and 00074 is triggered to start from TCP using tcp_timer_needed() */ 00075 {TCP_TMR_INTERVAL, HANDLER(tcp_tmr)}, 00076 #endif /* LWIP_TCP */ 00077 #if LWIP_IPV4 00078 #if IP_REASSEMBLY 00079 {IP_TMR_INTERVAL, HANDLER(ip_reass_tmr)}, 00080 #endif /* IP_REASSEMBLY */ 00081 #if LWIP_ARP 00082 {ARP_TMR_INTERVAL, HANDLER(etharp_tmr)}, 00083 #endif /* LWIP_ARP */ 00084 #if LWIP_DHCP 00085 {DHCP_COARSE_TIMER_MSECS, HANDLER(dhcp_coarse_tmr)}, 00086 {DHCP_FINE_TIMER_MSECS, HANDLER(dhcp_fine_tmr)}, 00087 #endif /* LWIP_DHCP */ 00088 #if LWIP_AUTOIP 00089 {AUTOIP_TMR_INTERVAL, HANDLER(autoip_tmr)}, 00090 #endif /* LWIP_AUTOIP */ 00091 #if LWIP_IGMP 00092 {IGMP_TMR_INTERVAL, HANDLER(igmp_tmr)}, 00093 #endif /* LWIP_IGMP */ 00094 #endif /* LWIP_IPV4 */ 00095 #if LWIP_DNS 00096 {DNS_TMR_INTERVAL, HANDLER(dns_tmr)}, 00097 #endif /* LWIP_DNS */ 00098 #if LWIP_IPV6 00099 {ND6_TMR_INTERVAL, HANDLER(nd6_tmr)}, 00100 #if LWIP_IPV6_REASS 00101 {IP6_REASS_TMR_INTERVAL, HANDLER(ip6_reass_tmr)}, 00102 #endif /* LWIP_IPV6_REASS */ 00103 #if LWIP_IPV6_MLD 00104 {MLD6_TMR_INTERVAL, HANDLER(mld6_tmr)}, 00105 #endif /* LWIP_IPV6_MLD */ 00106 #endif /* LWIP_IPV6 */ 00107 }; 00108 00109 #if LWIP_TIMERS && !LWIP_TIMERS_CUSTOM 00110 00111 /** The one and only timeout list */ 00112 static struct sys_timeo *next_timeout; 00113 static u32_t timeouts_last_time; 00114 00115 #if LWIP_TCP 00116 /** global variable that shows if the tcp timer is currently scheduled or not */ 00117 static int tcpip_tcp_timer_active; 00118 00119 /** 00120 * Timer callback function that calls tcp_tmr() and reschedules itself. 00121 * 00122 * @param arg unused argument 00123 */ 00124 static void 00125 tcpip_tcp_timer(void *arg) 00126 { 00127 LWIP_UNUSED_ARG(arg); 00128 00129 /* call TCP timer handler */ 00130 tcp_tmr(); 00131 /* timer still needed? */ 00132 if (tcp_active_pcbs || tcp_tw_pcbs) { 00133 /* restart timer */ 00134 sys_timeout(TCP_TMR_INTERVAL, tcpip_tcp_timer, NULL); 00135 } else { 00136 /* disable timer */ 00137 tcpip_tcp_timer_active = 0; 00138 } 00139 } 00140 00141 /** 00142 * Called from TCP_REG when registering a new PCB: 00143 * the reason is to have the TCP timer only running when 00144 * there are active (or time-wait) PCBs. 00145 */ 00146 void 00147 tcp_timer_needed(void) 00148 { 00149 /* timer is off but needed again? */ 00150 if (!tcpip_tcp_timer_active && (tcp_active_pcbs || tcp_tw_pcbs)) { 00151 /* enable and start timer */ 00152 tcpip_tcp_timer_active = 1; 00153 sys_timeout(TCP_TMR_INTERVAL, tcpip_tcp_timer, NULL); 00154 } 00155 } 00156 #endif /* LWIP_TCP */ 00157 00158 /** 00159 * Timer callback function that calls mld6_tmr() and reschedules itself. 00160 * 00161 * @param arg unused argument 00162 */ 00163 static void 00164 cyclic_timer(void *arg) 00165 { 00166 const struct lwip_cyclic_timer* cyclic = (const struct lwip_cyclic_timer*)arg; 00167 #if LWIP_DEBUG_TIMERNAMES 00168 LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: %s()\n", cyclic->handler_name)); 00169 #endif 00170 cyclic->handler(); 00171 sys_timeout(cyclic->interval_ms, cyclic_timer, arg); 00172 } 00173 00174 /** Initialize this module */ 00175 void sys_timeouts_init(void) 00176 { 00177 size_t i; 00178 /* tcp_tmr() at index 0 is started on demand */ 00179 for (i = 1; i < LWIP_ARRAYSIZE(lwip_cyclic_timers); i++) { 00180 /* we have to cast via size_t to get rid of const warning 00181 (this is OK as cyclic_timer() casts back to const* */ 00182 sys_timeout(lwip_cyclic_timers[i].interval_ms, cyclic_timer, LWIP_CONST_CAST(void*, &lwip_cyclic_timers[i])); 00183 } 00184 00185 /* Initialise timestamp for sys_check_timeouts */ 00186 timeouts_last_time = sys_now(); 00187 } 00188 00189 /** 00190 * Create a one-shot timer (aka timeout). Timeouts are processed in the 00191 * following cases: 00192 * - while waiting for a message using sys_timeouts_mbox_fetch() 00193 * - by calling sys_check_timeouts() (NO_SYS==1 only) 00194 * 00195 * @param msecs time in milliseconds after that the timer should expire 00196 * @param handler callback function to call when msecs have elapsed 00197 * @param arg argument to pass to the callback function 00198 */ 00199 #if LWIP_DEBUG_TIMERNAMES 00200 void 00201 sys_timeout_debug(u32_t msecs, sys_timeout_handler handler, void *arg, const char* handler_name) 00202 #else /* LWIP_DEBUG_TIMERNAMES */ 00203 void 00204 sys_timeout(u32_t msecs, sys_timeout_handler handler, void *arg) 00205 #endif /* LWIP_DEBUG_TIMERNAMES */ 00206 { 00207 struct sys_timeo *timeout, *t; 00208 u32_t now, diff; 00209 00210 timeout = (struct sys_timeo *)memp_malloc(MEMP_SYS_TIMEOUT); 00211 if (timeout == NULL) { 00212 LWIP_ASSERT("sys_timeout: timeout != NULL, pool MEMP_SYS_TIMEOUT is empty", timeout != NULL); 00213 return; 00214 } 00215 00216 now = sys_now(); 00217 if (next_timeout == NULL) { 00218 diff = 0; 00219 timeouts_last_time = now; 00220 } else { 00221 diff = now - timeouts_last_time; 00222 } 00223 00224 timeout->next = NULL; 00225 timeout->h = handler; 00226 timeout->arg = arg; 00227 timeout->time = msecs + diff; 00228 #if LWIP_DEBUG_TIMERNAMES 00229 timeout->handler_name = handler_name; 00230 LWIP_DEBUGF(TIMERS_DEBUG, ("sys_timeout: %p msecs=%"U32_F" handler=%s arg=%p\n", 00231 (void *)timeout, msecs, handler_name, (void *)arg)); 00232 #endif /* LWIP_DEBUG_TIMERNAMES */ 00233 00234 if (next_timeout == NULL) { 00235 next_timeout = timeout; 00236 return; 00237 } 00238 00239 if (next_timeout->time > msecs) { 00240 next_timeout->time -= msecs; 00241 timeout->next = next_timeout; 00242 next_timeout = timeout; 00243 } else { 00244 for (t = next_timeout; t != NULL; t = t->next) { 00245 timeout->time -= t->time; 00246 if (t->next == NULL || t->next->time > timeout->time) { 00247 if (t->next != NULL) { 00248 t->next->time -= timeout->time; 00249 } else if (timeout->time > msecs) { 00250 /* If this is the case, 'timeouts_last_time' and 'now' differs too much. 00251 This can be due to sys_check_timeouts() not being called at the right 00252 times, but also when stopping in a breakpoint. Anyway, let's assume 00253 this is not wanted, so add the first timer's time instead of 'diff' */ 00254 timeout->time = msecs + next_timeout->time; 00255 } 00256 timeout->next = t->next; 00257 t->next = timeout; 00258 break; 00259 } 00260 } 00261 } 00262 } 00263 00264 /** 00265 * Go through timeout list (for this task only) and remove the first matching 00266 * entry (subsequent entries remain untouched), even though the timeout has not 00267 * triggered yet. 00268 * 00269 * @param handler callback function that would be called by the timeout 00270 * @param arg callback argument that would be passed to handler 00271 */ 00272 void 00273 sys_untimeout(sys_timeout_handler handler, void *arg) 00274 { 00275 struct sys_timeo *prev_t, *t; 00276 00277 if (next_timeout == NULL) { 00278 return; 00279 } 00280 00281 for (t = next_timeout, prev_t = NULL; t != NULL; prev_t = t, t = t->next) { 00282 if ((t->h == handler) && (t->arg == arg)) { 00283 /* We have a match */ 00284 /* Unlink from previous in list */ 00285 if (prev_t == NULL) { 00286 next_timeout = t->next; 00287 } else { 00288 prev_t->next = t->next; 00289 } 00290 /* If not the last one, add time of this one back to next */ 00291 if (t->next != NULL) { 00292 t->next->time += t->time; 00293 } 00294 memp_free(MEMP_SYS_TIMEOUT, t); 00295 return; 00296 } 00297 } 00298 return; 00299 } 00300 00301 /** 00302 * @ingroup lwip_nosys 00303 * Handle timeouts for NO_SYS==1 (i.e. without using 00304 * tcpip_thread/sys_timeouts_mbox_fetch(). Uses sys_now() to call timeout 00305 * handler functions when timeouts expire. 00306 * 00307 * Must be called periodically from your main loop. 00308 */ 00309 #if !NO_SYS && !defined __DOXYGEN__ 00310 static 00311 #endif /* !NO_SYS */ 00312 void 00313 sys_check_timeouts(void) 00314 { 00315 if (next_timeout) { 00316 struct sys_timeo *tmptimeout; 00317 u32_t diff; 00318 sys_timeout_handler handler; 00319 void *arg; 00320 u8_t had_one; 00321 u32_t now; 00322 00323 now = sys_now(); 00324 /* this cares for wraparounds */ 00325 diff = now - timeouts_last_time; 00326 do { 00327 PBUF_CHECK_FREE_OOSEQ(); 00328 had_one = 0; 00329 tmptimeout = next_timeout; 00330 if (tmptimeout && (tmptimeout->time <= diff)) { 00331 /* timeout has expired */ 00332 had_one = 1; 00333 timeouts_last_time += tmptimeout->time; 00334 diff -= tmptimeout->time; 00335 next_timeout = tmptimeout->next; 00336 handler = tmptimeout->h; 00337 arg = tmptimeout->arg; 00338 #if LWIP_DEBUG_TIMERNAMES 00339 if (handler != NULL) { 00340 LWIP_DEBUGF(TIMERS_DEBUG, ("sct calling h=%s arg=%p\n", 00341 tmptimeout->handler_name, arg)); 00342 } 00343 #endif /* LWIP_DEBUG_TIMERNAMES */ 00344 memp_free(MEMP_SYS_TIMEOUT, tmptimeout); 00345 if (handler != NULL) { 00346 #if !NO_SYS 00347 /* For LWIP_TCPIP_CORE_LOCKING, lock the core before calling the 00348 timeout handler function. */ 00349 LOCK_TCPIP_CORE(); 00350 #endif /* !NO_SYS */ 00351 handler(arg); 00352 #if !NO_SYS 00353 UNLOCK_TCPIP_CORE(); 00354 #endif /* !NO_SYS */ 00355 } 00356 LWIP_TCPIP_THREAD_ALIVE(); 00357 } 00358 /* repeat until all expired timers have been called */ 00359 } while (had_one); 00360 } 00361 } 00362 00363 /** Set back the timestamp of the last call to sys_check_timeouts() 00364 * This is necessary if sys_check_timeouts() hasn't been called for a long 00365 * time (e.g. while saving energy) to prevent all timer functions of that 00366 * period being called. 00367 */ 00368 void 00369 sys_restart_timeouts(void) 00370 { 00371 timeouts_last_time = sys_now(); 00372 } 00373 00374 /** Return the time left before the next timeout is due. If no timeouts are 00375 * enqueued, returns 0xffffffff 00376 */ 00377 #if !NO_SYS 00378 static 00379 #endif /* !NO_SYS */ 00380 u32_t 00381 sys_timeouts_sleeptime(void) 00382 { 00383 u32_t diff; 00384 if (next_timeout == NULL) { 00385 return 0xffffffff; 00386 } 00387 diff = sys_now() - timeouts_last_time; 00388 if (diff > next_timeout->time) { 00389 return 0; 00390 } else { 00391 return next_timeout->time - diff; 00392 } 00393 } 00394 00395 #if !NO_SYS 00396 00397 /** 00398 * Wait (forever) for a message to arrive in an mbox. 00399 * While waiting, timeouts are processed. 00400 * 00401 * @param mbox the mbox to fetch the message from 00402 * @param msg the place to store the message 00403 */ 00404 void 00405 sys_timeouts_mbox_fetch(sys_mbox_t *mbox, void **msg) 00406 { 00407 u32_t sleeptime; 00408 00409 again: 00410 if (!next_timeout) { 00411 sys_arch_mbox_fetch(mbox, msg, 0); 00412 return; 00413 } 00414 00415 sleeptime = sys_timeouts_sleeptime(); 00416 if (sleeptime == 0 || sys_arch_mbox_fetch(mbox, msg, sleeptime) == SYS_ARCH_TIMEOUT) { 00417 /* If a SYS_ARCH_TIMEOUT value is returned, a timeout occurred 00418 before a message could be fetched. */ 00419 sys_check_timeouts(); 00420 /* We try again to fetch a message from the mbox. */ 00421 goto again; 00422 } 00423 } 00424 00425 #endif /* NO_SYS */ 00426 00427 #else /* LWIP_TIMERS && !LWIP_TIMERS_CUSTOM */ 00428 /* Satisfy the TCP code which calls this function */ 00429 void 00430 tcp_timer_needed(void) 00431 { 00432 } 00433 #endif /* LWIP_TIMERS && !LWIP_TIMERS_CUSTOM */
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