minix/lib/liblwip/core/timers.c

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/**
* @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/timers.h"
#if LWIP_TIMERS
#include "lwip/def.h"
#include "lwip/memp.h"
#include "lwip/tcpip.h"
#include "lwip/tcp_impl.h"
#include "lwip/ip_frag.h"
#include "netif/etharp.h"
#include "lwip/dhcp.h"
#include "lwip/autoip.h"
#include "lwip/igmp.h"
#include "lwip/dns.h"
/** The one and only timeout list */
static struct sys_timeo *next_timeout;
#if NO_SYS
static u32_t timeouts_last_time;
#endif /* NO_SYS */
#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)
{
/* 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 */
#if IP_REASSEMBLY
/**
* Timer callback function that calls ip_reass_tmr() and reschedules itself.
*
* @param arg unused argument
*/
static void
ip_reass_timer(void *arg)
{
LWIP_UNUSED_ARG(arg);
LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: ip_reass_tmr()\n"));
ip_reass_tmr();
sys_timeout(IP_TMR_INTERVAL, ip_reass_timer, NULL);
}
#endif /* IP_REASSEMBLY */
#if LWIP_ARP
/**
* Timer callback function that calls etharp_tmr() and reschedules itself.
*
* @param arg unused argument
*/
static void
arp_timer(void *arg)
{
LWIP_UNUSED_ARG(arg);
LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: etharp_tmr()\n"));
etharp_tmr();
sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);
}
#endif /* LWIP_ARP */
#if LWIP_DHCP
/**
* Timer callback function that calls dhcp_coarse_tmr() and reschedules itself.
*
* @param arg unused argument
*/
static void
dhcp_timer_coarse(void *arg)
{
LWIP_UNUSED_ARG(arg);
LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: dhcp_coarse_tmr()\n"));
dhcp_coarse_tmr();
sys_timeout(DHCP_COARSE_TIMER_MSECS, dhcp_timer_coarse, NULL);
}
/**
* Timer callback function that calls dhcp_fine_tmr() and reschedules itself.
*
* @param arg unused argument
*/
static void
dhcp_timer_fine(void *arg)
{
LWIP_UNUSED_ARG(arg);
LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: dhcp_fine_tmr()\n"));
dhcp_fine_tmr();
sys_timeout(DHCP_FINE_TIMER_MSECS, dhcp_timer_fine, NULL);
}
#endif /* LWIP_DHCP */
#if LWIP_AUTOIP
/**
* Timer callback function that calls autoip_tmr() and reschedules itself.
*
* @param arg unused argument
*/
static void
autoip_timer(void *arg)
{
LWIP_UNUSED_ARG(arg);
LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: autoip_tmr()\n"));
autoip_tmr();
sys_timeout(AUTOIP_TMR_INTERVAL, autoip_timer, NULL);
}
#endif /* LWIP_AUTOIP */
#if LWIP_IGMP
/**
* Timer callback function that calls igmp_tmr() and reschedules itself.
*
* @param arg unused argument
*/
static void
igmp_timer(void *arg)
{
LWIP_UNUSED_ARG(arg);
LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: igmp_tmr()\n"));
igmp_tmr();
sys_timeout(IGMP_TMR_INTERVAL, igmp_timer, NULL);
}
#endif /* LWIP_IGMP */
#if LWIP_DNS
/**
* Timer callback function that calls dns_tmr() and reschedules itself.
*
* @param arg unused argument
*/
static void
dns_timer(void *arg)
{
LWIP_UNUSED_ARG(arg);
LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: dns_tmr()\n"));
dns_tmr();
sys_timeout(DNS_TMR_INTERVAL, dns_timer, NULL);
}
#endif /* LWIP_DNS */
/** Initialize this module */
void sys_timeouts_init(void)
{
#if IP_REASSEMBLY
sys_timeout(IP_TMR_INTERVAL, ip_reass_timer, NULL);
#endif /* IP_REASSEMBLY */
#if LWIP_ARP
sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);
#endif /* LWIP_ARP */
#if LWIP_DHCP
sys_timeout(DHCP_COARSE_TIMER_MSECS, dhcp_timer_coarse, NULL);
sys_timeout(DHCP_FINE_TIMER_MSECS, dhcp_timer_fine, NULL);
#endif /* LWIP_DHCP */
#if LWIP_AUTOIP
sys_timeout(AUTOIP_TMR_INTERVAL, autoip_timer, NULL);
#endif /* LWIP_AUTOIP */
#if LWIP_IGMP
sys_timeout(IGMP_TMR_INTERVAL, igmp_timer, NULL);
#endif /* LWIP_IGMP */
#if LWIP_DNS
sys_timeout(DNS_TMR_INTERVAL, dns_timer, NULL);
#endif /* LWIP_DNS */
#if NO_SYS
/* Initialise timestamp for sys_check_timeouts */
timeouts_last_time = sys_now();
#endif
}
/**
* 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;
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 = msecs;
#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 (next_timeout->time > msecs) {
next_timeout->time -= msecs;
timeout->next = next_timeout;
next_timeout = timeout;
} else {
for(t = next_timeout; t != NULL; t = t->next) {
timeout->time -= t->time;
if (t->next == NULL || t->next->time > timeout->time) {
if (t->next != NULL) {
t->next->time -= timeout->time;
}
timeout->next = t->next;
t->next = timeout;
break;
}
}
}
}
/**
* Go through timeout list (for this task only) and remove the first matching
* entry, even though the timeout has not triggered yet.
*
* @note This function only works as expected if there is only one timeout
* calling 'handler' in the list of timeouts.
*
* @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;
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;
}
#if NO_SYS
/** 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)
{
struct sys_timeo *tmptimeout;
u32_t diff;
sys_timeout_handler handler;
void *arg;
int had_one;
u32_t now;
now = sys_now();
if (next_timeout) {
/* this cares for wraparounds */
diff = LWIP_U32_DIFF(now, timeouts_last_time);
do
{
had_one = 0;
tmptimeout = next_timeout;
if (tmptimeout->time <= diff) {
/* timeout has expired */
had_one = 1;
timeouts_last_time = now;
diff -= tmptimeout->time;
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);
}
}
/* repeat until all expired timers have been called */
}while(had_one);
}
}
/** Set back the timestamp of the last call to sys_check_timeouts()
* 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)
{
timeouts_last_time = sys_now();
}
#else /* 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 time_needed;
struct sys_timeo *tmptimeout;
sys_timeout_handler handler;
void *arg;
again:
if (!next_timeout) {
time_needed = sys_arch_mbox_fetch(mbox, msg, 0);
} else {
if (next_timeout->time > 0) {
time_needed = sys_arch_mbox_fetch(mbox, msg, next_timeout->time);
} else {
time_needed = SYS_ARCH_TIMEOUT;
}
if (time_needed == SYS_ARCH_TIMEOUT) {
/* If time == SYS_ARCH_TIMEOUT, a timeout occured before a message
could be fetched. We should now call the timeout handler and
deallocate the memory allocated for the timeout. */
tmptimeout = next_timeout;
next_timeout = tmptimeout->next;
handler = tmptimeout->h;
arg = tmptimeout->arg;
#if LWIP_DEBUG_TIMERNAMES
if (handler != NULL) {
LWIP_DEBUGF(TIMERS_DEBUG, ("stmf calling h=%s arg=%p\n",
tmptimeout->handler_name, arg));
}
#endif /* LWIP_DEBUG_TIMERNAMES */
memp_free(MEMP_SYS_TIMEOUT, tmptimeout);
if (handler != NULL) {
/* For LWIP_TCPIP_CORE_LOCKING, lock the core before calling the
timeout handler function. */
LOCK_TCPIP_CORE();
handler(arg);
UNLOCK_TCPIP_CORE();
}
LWIP_TCPIP_THREAD_ALIVE();
/* We try again to fetch a message from the mbox. */
goto again;
} else {
/* If time != SYS_ARCH_TIMEOUT, a message was received before the timeout
occured. The time variable is set to the number of
milliseconds we waited for the message. */
if (time_needed < next_timeout->time) {
next_timeout->time -= time_needed;
} else {
next_timeout->time = 0;
}
}
}
}
#endif /* NO_SYS */
#else /* LWIP_TIMERS */
/* Satisfy the TCP code which calls this function */
void
tcp_timer_needed(void)
{
}
#endif /* LWIP_TIMERS */