1、信号量Pend和Post
void OSSemPend (OS_EVENT *pevent,
INT32U timeout,
INT8U *perr)
{
OS_CPU_SR cpu_sr = 0u;
if (pevent->OSEventType != OS_EVENT_TYPE_SEM) {
*perr = OS_ERR_EVENT_TYPE;
return;
}
if (OSIntNesting > 0u) {
*perr = OS_ERR_PEND_ISR;
return;
}
if (OSLockNesting > 0u) {
*perr = OS_ERR_PEND_LOCKED;
return;
}
OS_ENTER_CRITICAL();
if (pevent->OSEventCnt > 0u) {
pevent->OSEventCnt--; /* 如果计数器>0,则-1返回 */
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return;
}
OSTCBCur->OSTCBStat |= OS_STAT_SEM;
OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK;
OSTCBCur->OSTCBDly = timeout; /* 否则更新程序状态字和延时节拍 */
OS_EventTaskWait(pevent); /* 让当前任务等待 */
OS_EXIT_CRITICAL();
OS_Sched();/* 进行一次调度,由当前任务切换到其他任务,等待事件触发之后,再切回来 */
OS_ENTER_CRITICAL();
switch (OSTCBCur->OSTCBStatPend) {
case OS_STAT_PEND_OK:
*perr = OS_ERR_NONE;
break;
case OS_STAT_PEND_ABORT:
*perr = OS_ERR_PEND_ABORT;
break;
case OS_STAT_PEND_TO:
default:
OS_EventTaskRemove(OSTCBCur, pevent); /* 超时,将当前任务移除等待列表 */
*perr = OS_ERR_TIMEOUT;
break;
}
OSTCBCur->OSTCBStat = OS_STAT_RDY;
OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK;
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0;
/* 还原状态信息 */
OS_EXIT_CRITICAL();
}
INT8U OSSemPost (OS_EVENT *pevent)
{
OS_CPU_SR cpu_sr = 0u;
if (pevent->OSEventType != OS_EVENT_TYPE_SEM) {
return (OS_ERR_EVENT_TYPE);
}
OS_ENTER_CRITICAL();
if (pevent->OSEventGrp != 0u) {
/* 是否有任务在等待信号量 */
(void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_SEM, OS_STAT_PEND_OK);
OS_EXIT_CRITICAL();
OS_Sched(); /* 有任务则等待信号量,则是其中最高的就绪且调度一次 */
return (OS_ERR_NONE);
}
if (pevent->OSEventCnt < 65535u) {
pevent->OSEventCnt++; /* 没有任务等待信号量,计数器+1 */
OS_EXIT_CRITICAL();
return (OS_ERR_NONE);
}
OS_EXIT_CRITICAL();
return (OS_ERR_SEM_OVF);
}
2、消息队列Pend和Post
void *OSQPend (OS_EVENT *pevent,
INT32U timeout,
INT8U *perr)
{
void *pmsg;
OS_Q *pq;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#if OS_ARG_CHK_EN > 0u
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
*perr = OS_ERR_PEVENT_NULL;
return ((void *)0);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_Q) {/* Validate event block type */
*perr = OS_ERR_EVENT_TYPE;
return ((void *)0);
}
if (OSIntNesting > 0u) { /* See if called from ISR ... */
*perr = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return ((void *)0);
}
if (OSLockNesting > 0u) { /* See if called with scheduler locked ... */
*perr = OS_ERR_PEND_LOCKED; /* ... can't PEND when locked */
return ((void *)0);
}
OS_ENTER_CRITICAL();
pq = (OS_Q *)pevent->OSEventPtr; /* Point at queue control block */
if (pq->OSQEntries > 0u) { /* See if any messages in the queue */
pmsg = *pq->OSQOut++; /* Yes, extract oldest message from the queue */
pq->OSQEntries--; /* Update the number of entries in the queue */
if (pq->OSQOut == pq->OSQEnd) { /* Wrap OUT pointer if we are at the end of the queue */
pq->OSQOut = pq->OSQStart;
}
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return (pmsg); /* Return message received */
}
OSTCBCur->OSTCBStat |= OS_STAT_Q; /* Task will have to pend for a message to be posted */
OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK;
OSTCBCur->OSTCBDly = timeout; /* Load timeout into TCB */
OS_EventTaskWait(pevent); /* Suspend task until event or timeout occurs */
OS_EXIT_CRITICAL();
OS_Sched(); /* Find next highest priority task ready to run */
OS_ENTER_CRITICAL();
switch (OSTCBCur->OSTCBStatPend) { /* See if we timed-out or aborted */
case OS_STAT_PEND_OK: /* Extract message from TCB (Put there by QPost) */
pmsg = OSTCBCur->OSTCBMsg;
*perr = OS_ERR_NONE;
break;
case OS_STAT_PEND_ABORT:
pmsg = (void *)0;
*perr = OS_ERR_PEND_ABORT; /* Indicate that we aborted */
break;
case OS_STAT_PEND_TO:
default:
OS_EventTaskRemove(OSTCBCur, pevent);
pmsg = (void *)0;
*perr = OS_ERR_TIMEOUT; /* Indicate that we didn't get event within TO */
break;
}
OSTCBCur->OSTCBStat = OS_STAT_RDY; /* Set task status to ready */
OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK; /* Clear pend status */
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; /* Clear event pointers */
#if (OS_EVENT_MULTI_EN > 0u)
OSTCBCur->OSTCBEventMultiPtr = (OS_EVENT **)0;
#endif
OSTCBCur->OSTCBMsg = (void *)0; /* Clear received message */
OS_EXIT_CRITICAL();
return (pmsg); /* Return received message */
}
INT8U OSQPost (OS_EVENT *pevent,
void *pmsg)
{
OS_Q *pq;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#if OS_ARG_CHK_EN > 0u
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
return (OS_ERR_PEVENT_NULL);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_Q) { /* Validate event block type */
return (OS_ERR_EVENT_TYPE);
}
OS_ENTER_CRITICAL();
if (pevent->OSEventGrp != 0u) { /* See if any task pending on queue */
/* Ready highest priority task waiting on event */
(void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_Q, OS_STAT_PEND_OK);
OS_EXIT_CRITICAL();
OS_Sched(); /* Find highest priority task ready to run */
return (OS_ERR_NONE);
}
pq = (OS_Q *)pevent->OSEventPtr; /* Point to queue control block */
if (pq->OSQEntries >= pq->OSQSize) { /* Make sure queue is not full */
OS_EXIT_CRITICAL();
return (OS_ERR_Q_FULL);
}
*pq->OSQIn++ = pmsg; /* Insert message into queue */
pq->OSQEntries++; /* Update the nbr of entries in the queue */
if (pq->OSQIn == pq->OSQEnd) { /* Wrap IN ptr if we are at end of queue */
pq->OSQIn = pq->OSQStart;
}
OS_EXIT_CRITICAL();
return (OS_ERR_NONE);
}