wdogs: Fix counting of free, pre-allocated wdog timers. The could could get decremented below zero in some situations

This commit is contained in:
Gregory Nutt 2015-08-21 11:30:22 -06:00
parent 12b1c04508
commit 89b5ef8d35
3 changed files with 23 additions and 9 deletions

View File

@ -10854,3 +10854,7 @@
state.rf_recvlen == -1. I have not checked if data are accumulated state.rf_recvlen == -1. I have not checked if data are accumulated
to the right position in the buffer however. From Pavel Pisa to the right position in the buffer however. From Pavel Pisa
(2015-08-15). (2015-08-15).
* sched/wdog/wd_create.c: Correct a counting error in the number
of available watchdog timers. When the number of free timers is
low, the counter could be incremented below zero (2015-08-15).

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@ -916,11 +916,11 @@ static uint16_t recvfrom_tcpinterrupt(FAR struct net_driver_s *dev,
/* Report an error only if no data has been received. (If /* Report an error only if no data has been received. (If
* CONFIG_NET_TCP_RECVDELAY then rf_recvlen should always be * CONFIG_NET_TCP_RECVDELAY then rf_recvlen should always be
* zero). * less than or equal to zero).
*/ */
#if CONFIG_NET_TCP_RECVDELAY > 0 #if CONFIG_NET_TCP_RECVDELAY > 0
if (pstate->rf_recvlen == 0) if (pstate->rf_recvlen <= 0)
#endif #endif
{ {
/* Report the timeout error */ /* Report the timeout error */

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@ -109,24 +109,34 @@ WDOG_ID wd_create (void)
if (g_wdnfree > CONFIG_WDOG_INTRESERVE || up_interrupt_context()) if (g_wdnfree > CONFIG_WDOG_INTRESERVE || up_interrupt_context())
{ {
/* Remove the watchdog timer from the free list and decrement the /* Remove the watchdog timer from the free list */
* count of free timers all with interrupts disabled.
*/
wdog = (FAR struct wdog_s *)sq_remfirst(&g_wdfreelist); wdog = (FAR struct wdog_s *)sq_remfirst(&g_wdfreelist);
DEBUGASSERT(g_wdnfree > 0);
g_wdnfree--;
irqrestore(state);
/* Did we get one? */ /* Did we get one? */
if (wdog) if (wdog)
{ {
/* Yes.. Clear the forward link and all flags */ /* Yes.. decrement the count of free, pre-allocated timers (all
* with interrupts disabled).
*/
DEBUGASSERT(g_wdnfree > 0 && wdog != NULL);
g_wdnfree--;
/* Clear the forward link and all flags */
wdog->next = NULL; wdog->next = NULL;
wdog->flags = 0; wdog->flags = 0;
} }
else
{
/* We didn't get one... The count should then be exactly zero */
DEBUGASSERT(g_wdnfree == 0);
}
irqrestore(state);
} }
/* We are in a normal tasking context AND there are not enough unreserved, /* We are in a normal tasking context AND there are not enough unreserved,