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发表于 2009-9-22 16:02:39
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显示全部楼层
这个问题很简单,(6)之前任务重新调度,
6之后任务重新就绪,
1是队列就绪,2是超时,第三种情况我给出一种答案
#if OS_Q_PEND_ABORT_EN > 0
INT8U OSQPendAbort (OS_EVENT *pevent, INT8U opt, INT8U *perr)
{
INT8U nbr_tasks;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
#if OS_ARG_CHK_EN > 0
if (perr == (INT8U *)0) { /* Validate 'perr' */
return (0);
}
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
*perr = OS_ERR_PEVENT_NULL;
return (0);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_Q) { /* Validate event block type */
*perr = OS_ERR_EVENT_TYPE;
return (0);
}
OS_ENTER_CRITICAL();
if (pevent->OSEventGrp != 0) { /* See if any task waiting on queue? */
nbr_tasks = 0;
switch (opt) {
case OS_PEND_OPT_BROADCAST: /* Do we need to abort ALL waiting tasks? */
while (pevent->OSEventGrp != 0) { /* Yes, ready ALL tasks waiting on queue */
(void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_Q, OS_STAT_PEND_ABORT);
nbr_tasks++;
}
break;
case OS_PEND_OPT_NONE:
default: /* No, ready HPT waiting on queue */
(void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_Q, OS_STAT_PEND_ABORT);
nbr_tasks++;
break;
}
OS_EXIT_CRITICAL();
OS_Sched(); /* Find HPT ready to run */
*perr = OS_ERR_PEND_ABORT;
return (nbr_tasks);
}
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return (0); /* No tasks waiting on queue */
} |
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