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Diffstat (limited to 'lwip/src/core/timeouts.c')
| -rw-r--r-- | lwip/src/core/timeouts.c | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/lwip/src/core/timeouts.c b/lwip/src/core/timeouts.c new file mode 100644 index 0000000..f37acfe --- /dev/null +++ b/lwip/src/core/timeouts.c @@ -0,0 +1,451 @@ +/** + * @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 <adam@sics.se> + * 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/dhcp6.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 */ + +#define LWIP_MAX_TIMEOUT 0x7fffffff + +/* Check if timer's expiry time is greater than time and care about u32_t wraparounds */ +#define TIME_LESS_THAN(t, compare_to) ( (((u32_t)((t)-(compare_to))) > LWIP_MAX_TIMEOUT) ? 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 */ +#if LWIP_IPV6_DHCP6 + {DHCP6_TIMER_MSECS, HANDLER(dhcp6_tmr)}, +#endif /* LWIP_IPV6_DHCP6 */ +#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; + +static u32_t current_timeout_due_time; + +#if LWIP_TESTMODE +struct sys_timeo** +sys_timeouts_get_next_timeout(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 */ + +static void +#if LWIP_DEBUG_TIMERNAMES +sys_timeout_abs(u32_t abs_time, sys_timeout_handler handler, void *arg, const char *handler_name) +#else /* LWIP_DEBUG_TIMERNAMES */ +sys_timeout_abs(u32_t abs_time, sys_timeout_handler handler, void *arg) +#endif +{ + struct sys_timeo *timeout, *t; + + 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; + } + + timeout->next = NULL; + timeout->h = handler; + timeout->arg = arg; + timeout->time = abs_time; + +#if LWIP_DEBUG_TIMERNAMES + timeout->handler_name = handler_name; + LWIP_DEBUGF(TIMERS_DEBUG, ("sys_timeout: %p abs_time=%"U32_F" handler=%s arg=%p\n", + (void *)timeout, abs_time, handler_name, (void *)arg)); +#endif /* LWIP_DEBUG_TIMERNAMES */ + + if (next_timeout == NULL) { + next_timeout = timeout; + return; + } + if (TIME_LESS_THAN(timeout->time, next_timeout->time)) { + timeout->next = next_timeout; + next_timeout = timeout; + } else { + for (t = next_timeout; t != NULL; t = t->next) { + if ((t->next == NULL) || TIME_LESS_THAN(timeout->time, t->next->time)) { + timeout->next = t->next; + t->next = timeout; + break; + } + } + } +} + +/** + * Timer callback function that calls cyclic->handler() and reschedules itself. + * + * @param arg unused argument + */ +#if !LWIP_TESTMODE +static +#endif +void +lwip_cyclic_timer(void *arg) +{ + u32_t now; + u32_t next_timeout_time; + 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(); + + now = sys_now(); + next_timeout_time = (u32_t)(current_timeout_due_time + cyclic->interval_ms); /* overflow handled by TIME_LESS_THAN macro */ + if (TIME_LESS_THAN(next_timeout_time, now)) { + /* timer would immediately expire again -> "overload" -> restart without any correction */ +#if LWIP_DEBUG_TIMERNAMES + sys_timeout_abs((u32_t)(now + cyclic->interval_ms), lwip_cyclic_timer, arg, cyclic->handler_name); +#else + sys_timeout_abs((u32_t)(now + cyclic->interval_ms), lwip_cyclic_timer, arg); +#endif + + } else { + /* correct cyclic interval with handler execution delay and sys_check_timeouts jitter */ +#if LWIP_DEBUG_TIMERNAMES + sys_timeout_abs(next_timeout_time, lwip_cyclic_timer, arg, cyclic->handler_name); +#else + sys_timeout_abs(next_timeout_time, lwip_cyclic_timer, arg); +#endif + } +} + +/** 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, lwip_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 */ +{ + u32_t next_timeout_time; + + LWIP_ASSERT_CORE_LOCKED(); + + LWIP_ASSERT("Timeout time too long, max is LWIP_UINT32_MAX/4 msecs", msecs <= (LWIP_UINT32_MAX / 4)); + + next_timeout_time = (u32_t)(sys_now() + msecs); /* overflow handled by TIME_LESS_THAN macro */ + +#if LWIP_DEBUG_TIMERNAMES + sys_timeout_abs(next_timeout_time, handler, arg, handler_name); +#else + sys_timeout_abs(next_timeout_time, handler, arg); +#endif +} + +/** + * 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; + } + 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. + */ +void +sys_check_timeouts(void) +{ + u32_t now; + + LWIP_ASSERT_CORE_LOCKED(); + + /* Process only timers expired at the start of the function. */ + now = sys_now(); + + do { + struct sys_timeo *tmptimeout; + sys_timeout_handler handler; + void *arg; + + PBUF_CHECK_FREE_OOSEQ(); + + tmptimeout = next_timeout; + if (tmptimeout == NULL) { + return; + } + + if (TIME_LESS_THAN(now, tmptimeout->time)) { + return; + } + + /* Timeout has expired */ + next_timeout = tmptimeout->next; + handler = tmptimeout->h; + arg = tmptimeout->arg; + current_timeout_due_time = tmptimeout->time; +#if LWIP_DEBUG_TIMERNAMES + if (handler != NULL) { + LWIP_DEBUGF(TIMERS_DEBUG, ("sct calling h=%s t=%"U32_F" arg=%p\n", + tmptimeout->handler_name, sys_now() - tmptimeout->time, 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 (1); +} + +/** Rebase the timeout times to the current time. + * This is necessary if sys_check_timeouts() hasn't been called for a long + * time (e.g. while saving energy) to prevent all timer functions of that + * period being called. + */ +void +sys_restart_timeouts(void) +{ + u32_t now; + u32_t base; + struct sys_timeo *t; + + if (next_timeout == NULL) { + return; + } + + now = sys_now(); + base = next_timeout->time; + + for (t = next_timeout; t != NULL; t = t->next) { + t->time = (t->time - base) + now; + } +} + +/** Return the time left before the next timeout is due. If no timeouts are + * enqueued, returns 0xffffffff + */ +u32_t +sys_timeouts_sleeptime(void) +{ + u32_t now; + + LWIP_ASSERT_CORE_LOCKED(); + + if (next_timeout == NULL) { + return SYS_TIMEOUTS_SLEEPTIME_INFINITE; + } + now = sys_now(); + if (TIME_LESS_THAN(next_timeout->time, now)) { + return 0; + } else { + u32_t ret = (u32_t)(next_timeout->time - now); + LWIP_ASSERT("invalid sleeptime", ret <= LWIP_MAX_TIMEOUT); + return ret; + } +} + +#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 */ |