/*
* Check if and when lwIP has its next timeout, and set or cancel our timer
* accordingly.
*/
static void
set_lwip_timer(void)
{
uint32_t next_timeout;
clock_t ticks;
/* Ask lwIP when the next alarm is supposed to go off, if any. */
next_timeout = sys_timeouts_sleeptime();
/*
* Set or update the lwIP timer. We rely on set_timer() asking the
* kernel for an alarm only if the timeout is different from the one we
* gave it last time (if at all). However, due to conversions between
* absolute and relative times, and the fact that we cannot guarantee
* that the uptime itself does not change while executing these
* routines, set_timer() will sometimes be issuing a kernel call even
* if the alarm has not changed. Not a huge deal, but fixing this will
* require a different interface to lwIP and/or the timers library.
*/
if (next_timeout != (uint32_t)-1) {
/*
* Round up the next timeout (which is in milliseconds) to the
* number of clock ticks to add to the current time. Avoid any
* potential for overflows, no matter how unrealistic..
*/
if (next_timeout > TMRDIFF_MAX / sys_hz())
ticks = TMRDIFF_MAX;
else
ticks = (next_timeout * sys_hz() + 999) / 1000;
set_timer(&lwip_timer, ticks, expire_lwip_timer, 0 /*unused*/);
} else
cancel_timer(&lwip_timer); /* not really needed.. */
}
/**
* 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;
again:
if (!next_timeout) {
sys_arch_mbox_fetch(mbox, msg, 0);
return;
}
sleeptime = sys_timeouts_sleeptime();
if (sleeptime == 0 || sys_arch_mbox_fetch(mbox, msg, sleeptime) == 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;
}
}
