/** * @file * Stack-internal timers implementation. * This file includes timer callbacks for stack-internal timers as well as * functions to set up or stop timers and check for expired timers. * */ /* * Copyright (c) 2001-2004 Swedish Institute of Computer Science. * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * * This file is part of the lwIP TCP/IP stack. * * Author: Adam Dunkels * Simon Goldschmidt * */ #include "lwip/opt.h" #include "lwip/timeouts.h" #include "lwip/priv/tcp_priv.h" #include "lwip/def.h" #include "lwip/memp.h" #include "lwip/priv/tcpip_priv.h" #include "lwip/ip4_frag.h" #include "lwip/etharp.h" #include "lwip/dhcp.h" #include "lwip/autoip.h" #include "lwip/igmp.h" #include "lwip/dns.h" #include "lwip/nd6.h" #include "lwip/ip6_frag.h" #include "lwip/mld6.h" #include "lwip/sys.h" #include "lwip/pbuf.h" #if LWIP_DEBUG_TIMERNAMES #define HANDLER(x) x, #x #else /* LWIP_DEBUG_TIMERNAMES */ #define HANDLER(x) x #endif /* LWIP_DEBUG_TIMERNAMES */ /* Check if timer's expiry time is greater than time and care about u32_t wraparounds */ #define TIMER_LESS_THAN(timer, t) ( (((timer)->time == (t)) || (((u32_t)((timer)->time-(t))) > 0x7fffffff)) ? 1 : 0 ) /** This array contains all stack-internal cyclic timers. To get the number of * timers, use LWIP_ARRAYSIZE() */ const struct lwip_cyclic_timer lwip_cyclic_timers[] = { #if LWIP_TCP /* The TCP timer is a special case: it does not have to run always and is triggered to start from TCP using tcp_timer_needed() */ {TCP_TMR_INTERVAL, HANDLER(tcp_tmr)}, #endif /* LWIP_TCP */ #if LWIP_IPV4 #if IP_REASSEMBLY {IP_TMR_INTERVAL, HANDLER(ip_reass_tmr)}, #endif /* IP_REASSEMBLY */ #if LWIP_ARP {ARP_TMR_INTERVAL, HANDLER(etharp_tmr)}, #endif /* LWIP_ARP */ #if LWIP_DHCP {DHCP_COARSE_TIMER_MSECS, HANDLER(dhcp_coarse_tmr)}, {DHCP_FINE_TIMER_MSECS, HANDLER(dhcp_fine_tmr)}, #endif /* LWIP_DHCP */ #if LWIP_AUTOIP {AUTOIP_TMR_INTERVAL, HANDLER(autoip_tmr)}, #endif /* LWIP_AUTOIP */ #if LWIP_IGMP {IGMP_TMR_INTERVAL, HANDLER(igmp_tmr)}, #endif /* LWIP_IGMP */ #endif /* LWIP_IPV4 */ #if LWIP_DNS {DNS_TMR_INTERVAL, HANDLER(dns_tmr)}, #endif /* LWIP_DNS */ #if LWIP_IPV6 {ND6_TMR_INTERVAL, HANDLER(nd6_tmr)}, #if LWIP_IPV6_REASS {IP6_REASS_TMR_INTERVAL, HANDLER(ip6_reass_tmr)}, #endif /* LWIP_IPV6_REASS */ #if LWIP_IPV6_MLD {MLD6_TMR_INTERVAL, HANDLER(mld6_tmr)}, #endif /* LWIP_IPV6_MLD */ #endif /* LWIP_IPV6 */ }; const int lwip_num_cyclic_timers = LWIP_ARRAYSIZE(lwip_cyclic_timers); #if LWIP_TIMERS && !LWIP_TIMERS_CUSTOM /** The one and only timeout list */ static struct sys_timeo *next_timeout; #if LWIP_TESTMODE struct sys_timeo** lwip_sys_timers_get_next_timout(void) { return &next_timeout; } #endif #if LWIP_TCP /** global variable that shows if the tcp timer is currently scheduled or not */ static int tcpip_tcp_timer_active; /** * Timer callback function that calls tcp_tmr() and reschedules itself. * * @param arg unused argument */ static void tcpip_tcp_timer(void *arg) { LWIP_UNUSED_ARG(arg); /* call TCP timer handler */ tcp_tmr(); /* timer still needed? */ if (tcp_active_pcbs || tcp_tw_pcbs) { /* restart timer */ sys_timeout(TCP_TMR_INTERVAL, tcpip_tcp_timer, NULL); } else { /* disable timer */ tcpip_tcp_timer_active = 0; } } /** * Called from TCP_REG when registering a new PCB: * the reason is to have the TCP timer only running when * there are active (or time-wait) PCBs. */ void tcp_timer_needed(void) { LWIP_ASSERT_CORE_LOCKED(); /* timer is off but needed again? */ if (!tcpip_tcp_timer_active && (tcp_active_pcbs || tcp_tw_pcbs)) { /* enable and start timer */ tcpip_tcp_timer_active = 1; sys_timeout(TCP_TMR_INTERVAL, tcpip_tcp_timer, NULL); } } #endif /* LWIP_TCP */ /** * Timer callback function that calls cyclic->handler() and reschedules itself. * * @param arg unused argument */ static void cyclic_timer(void *arg) { const struct lwip_cyclic_timer *cyclic = (const struct lwip_cyclic_timer *)arg; #if LWIP_DEBUG_TIMERNAMES LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: %s()\n", cyclic->handler_name)); #endif cyclic->handler(); sys_timeout(cyclic->interval_ms, cyclic_timer, arg); } /** Initialize this module */ void sys_timeouts_init(void) { size_t i; /* tcp_tmr() at index 0 is started on demand */ for (i = (LWIP_TCP ? 1 : 0); i < LWIP_ARRAYSIZE(lwip_cyclic_timers); i++) { /* we have to cast via size_t to get rid of const warning (this is OK as cyclic_timer() casts back to const* */ sys_timeout(lwip_cyclic_timers[i].interval_ms, cyclic_timer, LWIP_CONST_CAST(void *, &lwip_cyclic_timers[i])); } } /** * Create a one-shot timer (aka timeout). Timeouts are processed in the * following cases: * - while waiting for a message using sys_timeouts_mbox_fetch() * - by calling sys_check_timeouts() (NO_SYS==1 only) * * @param msecs time in milliseconds after that the timer should expire * @param handler callback function to call when msecs have elapsed * @param arg argument to pass to the callback function */ #if LWIP_DEBUG_TIMERNAMES void sys_timeout_debug(u32_t msecs, sys_timeout_handler handler, void *arg, const char *handler_name) #else /* LWIP_DEBUG_TIMERNAMES */ void sys_timeout(u32_t msecs, sys_timeout_handler handler, void *arg) #endif /* LWIP_DEBUG_TIMERNAMES */ { struct sys_timeo *timeout, *t; u32_t now; LWIP_ASSERT_CORE_LOCKED(); timeout = (struct sys_timeo *)memp_malloc(MEMP_SYS_TIMEOUT); if (timeout == NULL) { LWIP_ASSERT("sys_timeout: timeout != NULL, pool MEMP_SYS_TIMEOUT is empty", timeout != NULL); return; } now = sys_now(); timeout->next = NULL; timeout->h = handler; timeout->arg = arg; timeout->time = (u32_t)(now + msecs); /* overflow handled by TIMER_LESS_THAN macro */ #if LWIP_DEBUG_TIMERNAMES timeout->handler_name = handler_name; LWIP_DEBUGF(TIMERS_DEBUG, ("sys_timeout: %p msecs=%"U32_F" handler=%s arg=%p\n", (void *)timeout, msecs, handler_name, (void *)arg)); #endif /* LWIP_DEBUG_TIMERNAMES */ if (next_timeout == NULL) { next_timeout = timeout; return; } if (TIMER_LESS_THAN(timeout, next_timeout->time)) { timeout->next = next_timeout; next_timeout = timeout; } else { for (t = next_timeout; t != NULL; t = t->next) { if ((t->next == NULL) || TIMER_LESS_THAN(timeout, t->next->time)) { timeout->next = t->next; t->next = timeout; break; } } } } /** * Go through timeout list (for this task only) and remove the first matching * entry (subsequent entries remain untouched), even though the timeout has not * triggered yet. * * @param handler callback function that would be called by the timeout * @param arg callback argument that would be passed to handler */ void sys_untimeout(sys_timeout_handler handler, void *arg) { struct sys_timeo *prev_t, *t; LWIP_ASSERT_CORE_LOCKED(); if (next_timeout == NULL) { return; } for (t = next_timeout, prev_t = NULL; t != NULL; prev_t = t, t = t->next) { if ((t->h == handler) && (t->arg == arg)) { /* We have a match */ /* Unlink from previous in list */ if (prev_t == NULL) { next_timeout = t->next; } else { prev_t->next = t->next; } /* If not the last one, add time of this one back to next */ if (t->next != NULL) { t->next->time += t->time; } memp_free(MEMP_SYS_TIMEOUT, t); return; } } return; } /** * @ingroup lwip_nosys * Handle timeouts for NO_SYS==1 (i.e. without using * tcpip_thread/sys_timeouts_mbox_fetch(). Uses sys_now() to call timeout * handler functions when timeouts expire. * * Must be called periodically from your main loop. */ #if !LWIP_TESTMODE && !NO_SYS && !defined __DOXYGEN__ static #endif /* !NO_SYS */ void sys_check_timeouts(void) { LWIP_ASSERT_CORE_LOCKED(); if (next_timeout) { struct sys_timeo *tmptimeout; sys_timeout_handler handler; void *arg; u8_t had_one; u32_t now; now = sys_now(); do { PBUF_CHECK_FREE_OOSEQ(); had_one = 0; tmptimeout = next_timeout; if (tmptimeout && TIMER_LESS_THAN(tmptimeout, now)) { /* timeout has expired */ had_one = 1; next_timeout = tmptimeout->next; handler = tmptimeout->h; arg = tmptimeout->arg; #if LWIP_DEBUG_TIMERNAMES if (handler != NULL) { LWIP_DEBUGF(TIMERS_DEBUG, ("sct calling h=%s arg=%p\n", tmptimeout->handler_name, arg)); } #endif /* LWIP_DEBUG_TIMERNAMES */ memp_free(MEMP_SYS_TIMEOUT, tmptimeout); if (handler != NULL) { handler(arg); } LWIP_TCPIP_THREAD_ALIVE(); } /* repeat until all expired timers have been called */ } while (had_one); } } /** * @deprecated Just delete your call to this function */ void sys_restart_timeouts(void) { } /** Return the time left before the next timeout is due. If no timeouts are * enqueued, returns 0xffffffff */ #if !LWIP_TESTMODE && !NO_SYS static #endif /* !NO_SYS */ u32_t sys_timeouts_sleeptime(void) { u32_t now; LWIP_ASSERT_CORE_LOCKED(); if (next_timeout == NULL) { return 0xffffffff; } now = sys_now(); if (TIMER_LESS_THAN(next_timeout, now)) { return 0; } else { return (u32_t)(next_timeout->time - now); } } #if !NO_SYS /** * Wait (forever) for a message to arrive in an mbox. * While waiting, timeouts are processed. * * @param mbox the mbox to fetch the message from * @param msg the place to store the message */ void sys_timeouts_mbox_fetch(sys_mbox_t *mbox, void **msg) { u32_t sleeptime, res; again: LWIP_ASSERT_CORE_LOCKED(); if (!next_timeout) { UNLOCK_TCPIP_CORE(); sys_arch_mbox_fetch(mbox, msg, 0); LOCK_TCPIP_CORE(); return; } sleeptime = sys_timeouts_sleeptime(); if (sleeptime == 0) { sys_check_timeouts(); /* We try again to fetch a message from the mbox. */ goto again; } UNLOCK_TCPIP_CORE(); res = sys_arch_mbox_fetch(mbox, msg, sleeptime); LOCK_TCPIP_CORE(); if (res == SYS_ARCH_TIMEOUT) { /* If a SYS_ARCH_TIMEOUT value is returned, a timeout occurred before a message could be fetched. */ sys_check_timeouts(); /* We try again to fetch a message from the mbox. */ goto again; } } #endif /* NO_SYS */ #else /* LWIP_TIMERS && !LWIP_TIMERS_CUSTOM */ /* Satisfy the TCP code which calls this function */ void tcp_timer_needed(void) { } #endif /* LWIP_TIMERS && !LWIP_TIMERS_CUSTOM */