void *OSQPend (OS_EVENT *pevent, INT16U timeout, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
void *msg;
OS_Q *pq;
if (OSIntNesting > 0) { /* See if called from ISR ... */
*err = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return ((void *)0);
}
#if OS_ARG_CHK_EN > 0
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
*err = OS_ERR_PEVENT_NULL;
return ((void *)0);
}
if (pevent->OSEventType != OS_EVENT_TYPE_Q) {/* Validate event block type */
*err = OS_ERR_EVENT_TYPE;
return ((void *)0);
}
#endif
OS_ENTER_CRITICAL();
pq = (OS_Q *)pevent->OSEventPtr; /* Point at queue control block */
if (pq->OSQEntries > 0) { /* See if any messages in the queue */
msg = *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();
*err = OS_NO_ERR;
return (msg); /* Return message received */
}
OSTCBCur->OSTCBStat |= OS_STAT_Q; /* Task will have to pend for a message to be posted */
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();
if (OSTCBCur->OSTCBStat & OS_STAT_Q) { /* Was task readied because of a timeout? */
OS_EventTO(pevent); /* Yes */
OS_EXIT_CRITICAL();
*err = OS_TIMEOUT; /* Indicate a timeout occured */
return ((void *)0); /* No message received */
}
msg = OSTCBCur->OSTCBMsg;/* No, Extract message from TCB (Put there by QPost) */
OSTCBCur->OSTCBMsg = (void *)0;
OSTCBCur->OSTCBStat = OS_STAT_RDY;
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; /* No longer waiting for event */
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
return (msg); /* Return message received */
}
void *OSMboxPend (OS_EVENT *pevent, INT16U timeout, INT8U *err)
{
void *msg;
#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 (err == (INT8U *)0) { /* Validate 'err' */
return ((void *)0);
}
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
*err = OS_ERR_PEVENT_NULL;
return ((void *)0);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */
*err = OS_ERR_EVENT_TYPE;
return ((void *)0);
}
if (OSIntNesting > 0) { /* See if called from ISR ... */
*err = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return ((void *)0);
}
OS_ENTER_CRITICAL();
msg = pevent->OSEventPtr;
if (msg != (void *)0) { /* See if there is already a message */
pevent->OSEventPtr = (void *)0; /* Clear the mailbox */
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
return (msg); /* Return the message received (or NULL) */
}
OSTCBCur->OSTCBStat |= OS_STAT_MBOX; /* Message not available, task will pend */
OSTCBCur->OSTCBPendTO = FALSE;
OSTCBCur->OSTCBDly = timeout; /* Load timeout in 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();
if (OSTCBCur->OSTCBPendTO == TRUE) { /* See if we were given the message */
OS_EventTO(pevent); /* Timed out, Make task ready */
OS_EXIT_CRITICAL();
*err = OS_TIMEOUT; /* Indicate that a timeout occured */
return ((void *)0); /* Return a NULL message */
}
msg = OSTCBCur->OSTCBMsg;
OSTCBCur->OSTCBMsg = (void *)0; /* Yes, clear message received */
OSTCBCur->OSTCBStat = OS_STAT_RDY;
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; /* No longer waiting for event */
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
return (msg); /* Return the message received */
}
void OSSemPend (OS_EVENT *pevent, INT16U timeout, INT8U *err)
{
#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 (err == (INT8U *)0) { /* Validate 'err' */
return;
}
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
*err = OS_ERR_PEVENT_NULL;
return;
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_SEM) { /* Validate event block type */
*err = OS_ERR_EVENT_TYPE;
return;
}
if (OSIntNesting > 0) { /* See if called from ISR ... */
*err = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return;
}
if (OSLockNesting > 0) { /* See if called with scheduler locked ... */
*err = OS_ERR_PEND_LOCKED; /* ... can't PEND when locked */
return;
}
OS_ENTER_CRITICAL();
if (pevent->OSEventCnt > 0) { /* If sem. is positive, resource available ... */
pevent->OSEventCnt--; /* ... decrement semaphore only if positive. */
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
return;
}
/* Otherwise, must wait until event occurs */
OSTCBCur->OSTCBStat |= OS_STAT_SEM; /* Resource not available, pend on semaphore */
OSTCBCur->OSTCBPendTO = OS_FALSE;
OSTCBCur->OSTCBDly = timeout; /* Store pend timeout in TCB */
OS_EventTaskWait(pevent); /* Suspend task until event or timeout occurs */
OS_EXIT_CRITICAL();
OS_Sched(); /* Find next highest priority task ready */
OS_ENTER_CRITICAL();
if (OSTCBCur->OSTCBPendTO == OS_TRUE) { /* See if we timedout */
OS_EventTO(pevent);
OS_EXIT_CRITICAL();
*err = OS_TIMEOUT; /* Indicate that didn't get event within TO */
return;
}
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0;
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
}
// 要求获得邮箱的消息
void *OSMboxPend (OS_EVENT *pevent, INT16U timeout, INT8U *err)
{
void *msg;
#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 (err == (INT8U *)0) /* Validate 'err' */
{
return ((void *)0);
}
if (pevent == (OS_EVENT *)0) /* Validate 'pevent' */
{
*err = OS_ERR_PEVENT_NULL;
return ((void *)0);
}
#endif
// 事件类型是邮箱?
if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) /* Validate event block type */
{
*err = OS_ERR_EVENT_TYPE;
return ((void *)0);
}
// 中断处理里不允许挂起
if (OSIntNesting > 0) /* See if called from ISR ... */
{
*err = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return ((void *)0);
}
// 调度禁止时不允许挂起
if (OSLockNesting > 0) /* See if called with scheduler locked ... */
{
*err = OS_ERR_PEND_LOCKED; /* ... can't PEND when locked */
return ((void *)0);
}
OS_ENTER_CRITICAL();
msg = pevent->OSEventPtr;
// 可获得邮箱消息?
if (msg != (void *)0) /* See if there is already a message */
{
// 清空邮箱
pevent->OSEventPtr = (void *)0; /* Clear the mailbox */
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
// 返回
return (msg); /* Return the message received (or NULL) */
}
// 如果获取不到邮箱信息，任务会挂起
// 更新任务状态标志
OSTCBCur->OSTCBStat |= OS_STAT_MBOX; /* Message not available, task will pend */
// 延时等待最大时间未到
OSTCBCur->OSTCBPendTO = OS_FALSE;
// 设置延时等待最大时间
OSTCBCur->OSTCBDly = timeout; /* Load timeout in TCB */
// 将任务添加到事件控制块的等待任务表
OS_EventTaskWait(pevent); /* Suspend task until event or timeout occurs */
OS_EXIT_CRITICAL();
// 找出优先级最高的任务并进行任务切换
OS_Sched(); /* Find next highest priority task ready to run */
// 当邮箱有效或者等待时间到后，
// 并且调用OSMboxPend()函数的任务再一次成为最高优先级任务,
// 就会回到这里继续执行
OS_ENTER_CRITICAL();
// 延时等待最大时间到了?
if (OSTCBCur->OSTCBPendTO == OS_TRUE) /* See if we were given the message */
{
// 由于等待超时而将任务置为就绪态。
OS_EventTO(pevent); /* Timed out, Make task ready */
OS_EXIT_CRITICAL();
*err = OS_TIMEOUT; /* Indicate that a timeout occured */
return ((void *)0); /* Return a NULL message */
}
// 邮箱可被获得:
// 获得邮箱消息
msg = OSTCBCur->OSTCBMsg;
// 清空邮箱
OSTCBCur->OSTCBMsg = (void *)0; /* Yes, clear message received */
// 更新任务状态标志
OSTCBCur->OSTCBStat = OS_STAT_RDY;
// 释放TCB里的ECB
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; /* No longer waiting for event */
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
return (msg); /* Return the message received */
}
// 要求获得一个信号量
void OSSemPend (OS_EVENT *pevent, INT16U timeout, INT8U *err)
{
#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 (err == (INT8U *)0) /* Validate 'err' */
{
return;
}
if (pevent == (OS_EVENT *)0) /* Validate 'pevent' */
{
*err = OS_ERR_PEVENT_NULL;
return;
}
#endif
// 确定事件类型是信号量
if (pevent->OSEventType != OS_EVENT_TYPE_SEM) /* Validate event block type */
{
*err = OS_ERR_EVENT_TYPE;
return;
}
// 中断处理里不允许挂起
if (OSIntNesting > 0) /* See if called from ISR ... */
{
*err = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return;
}
// 调度禁止时不允许挂起
if (OSLockNesting > 0) /* See if called with scheduler locked ... */
{
*err = OS_ERR_PEND_LOCKED; /* ... can't PEND when locked */
return;
}
OS_ENTER_CRITICAL();
// 如果信号量可用
if (pevent->OSEventCnt > 0) /* If sem. is positive, resource available ... */
{
// 获得信号量，计数器减一，即可用的资源减少一份
pevent->OSEventCnt--; /* ... decrement semaphore only if positive. */
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
// 返回
return;
}
// 否则，等待信号量 /* Otherwise, must wait until event occurs */
// 更新任务状态标志
OSTCBCur->OSTCBStat |= OS_STAT_SEM; /* Resource not available, pend on semaphore */
// 延时等待最大时间未到
OSTCBCur->OSTCBPendTO = OS_FALSE;
// 设置延时等待最大时间
OSTCBCur->OSTCBDly = timeout; /* Store pend timeout in TCB */
// 将任务添加到事件控制块的等待任务表
OS_EventTaskWait(pevent); /* Suspend task until event or timeout occurs */
OS_EXIT_CRITICAL();
// 找出优先级最高的任务并进行任务切换
OS_Sched(); /* Find next highest priority task ready */
// 当信号量有效或者等待时间到后，
// 并且调用 OSSemPend()函数的任务再一次成为最高优先级任务,
// 就会回到这里继续执行
OS_ENTER_CRITICAL();
// 是否延时等待最大时间到了?
if (OSTCBCur->OSTCBPendTO == OS_TRUE) /* See if we timedout */
{
// 由于等待超时而将任务置为就绪态。
OS_EventTO(pevent);
OS_EXIT_CRITICAL();
*err = OS_TIMEOUT; /* Indicate that didn't get event within TO */
return;
}
// 释放TCB里的ECB
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0;
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
}