📄 os_q.lst
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#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
BOOLEAN tasks_waiting;
OS_Q *pq;
if (OSIntNesting > 0) { /* See if called from ISR ... */
*err = OS_ERR_DEL_ISR; /* ... can't DELETE from an ISR */
return ((OS_EVENT *)0);
}
#if OS_ARG_CHK_EN > 0
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
*err = OS_ERR_PEVENT_NULL;
return (pevent);
}
if (pevent->OSEventType != OS_EVENT_TYPE_Q) { /* Validate event block type */
*err = OS_ERR_EVENT_TYPE;
return (pevent);
}
#endif
OS_ENTER_CRITICAL();
if (pevent->OSEventGrp != 0x00) { /* See if any tasks waiting on queue */
tasks_waiting = TRUE; /* Yes */
} else {
tasks_waiting = FALSE; /* No */
}
switch (opt) {
case OS_DEL_NO_PEND: /* Delete queue only if no task waiting */
if (tasks_waiting == FALSE) {
pq = pevent->OSEventPtr; /* Return OS_Q to free list */
pq->OSQPtr = OSQFreeList;
OSQFreeList = pq;
pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */
OSEventFreeList = pevent; /* Get next free event control block */
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
return ((OS_EVENT *)0); /* Queue has been deleted */
} else {
OS_EXIT_CRITICAL();
*err = OS_ERR_TASK_WAITING;
return (pevent);
}
case OS_DEL_ALWAYS: /* Always delete the queue */
while (pevent->OSEventGrp != 0x00) { /* Ready ALL tasks waiting for queue */
OS_EventTaskRdy(pevent, (void *)0, OS_STAT_Q);
}
pq = pevent->OSEventPtr; /* Return OS_Q to free list */
pq->OSQPtr = OSQFreeList;
OSQFreeList = pq;
pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */
OSEventFreeList = pevent; /* Get next free event control block */
OS_EXIT_CRITICAL();
if (tasks_waiting == TRUE) { /* Reschedule only if task(s) were waiting */
OS_Sched(); /* Find highest priority task ready to run */
}
*err = OS_NO_ERR;
return ((OS_EVENT *)0); /* Queue has been deleted */
C51 COMPILER V7.50 OS_Q 12/14/2005 10:56:01 PAGE 5
default:
OS_EXIT_CRITICAL();
*err = OS_ERR_INVALID_OPT;
return (pevent);
}
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* FLUSH QUEUE
*
* Description : This function is used to flush the contents of the message queue.
*
* Arguments : none
*
* Returns : OS_NO_ERR upon success
* OS_ERR_EVENT_TYPE If you didn't pass a pointer to a queue
* OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer
*********************************************************************************************************
*/
#if OS_Q_FLUSH_EN > 0
INT8U OSQFlush (OS_EVENT *pevent) reentrant
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_Q *pq;
#if OS_ARG_CHK_EN > 0
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
return (OS_ERR_PEVENT_NULL);
}
if (pevent->OSEventType != OS_EVENT_TYPE_Q) { /* Validate event block type */
return (OS_ERR_EVENT_TYPE);
}
#endif
OS_ENTER_CRITICAL();
pq = (OS_Q *)pevent->OSEventPtr; /* Point to queue storage structure */
pq->OSQIn = pq->OSQStart;
pq->OSQOut = pq->OSQStart;
pq->OSQEntries = 0;
OS_EXIT_CRITICAL();
return (OS_NO_ERR);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* PEND ON A QUEUE FOR A MESSAGE
*
* Description: This function waits for a message to be sent to a queue
*
* Arguments : pevent is a pointer to the event control block associated with the desired queue
*
* timeout is an optional timeout period (in clock ticks). If non-zero, your task will
* wait for a message to arrive at the queue up to the amount of time
C51 COMPILER V7.50 OS_Q 12/14/2005 10:56:01 PAGE 6
* specified by this argument. If you specify 0, however, your task will wait
* forever at the specified queue or, until a message arrives.
*
* err is a pointer to where an error message will be deposited. Possible error
* messages are:
*
* OS_NO_ERR The call was successful and your task received a
* message.
* OS_TIMEOUT A message was not received within the specified timeout
* OS_ERR_EVENT_TYPE You didn't pass a pointer to a queue
* OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer
* OS_ERR_PEND_ISR If you called this function from an ISR and the result
* would lead to a suspension.
*
* Returns : != (void *)0 is a pointer to the message received
* == (void *)0 if no message was received or,
* if 'pevent' is a NULL pointer or,
* if you didn't pass a pointer to a queue.
*********************************************************************************************************
*/
void *OSQPend (OS_EVENT *pevent, INT16U timeout, INT8U *err) reentrant
{
#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();
C51 COMPILER V7.50 OS_Q 12/14/2005 10:56:01 PAGE 7
msg = OSTCBCur->OSTCBMsg;
if (msg != (void *)0) { /* Did we get a message? */
OSTCBCur->OSTCBMsg = (void *)0; /* Extract message from TCB (Put there by QPost) */
OSTCBCur->OSTCBStat = OS_STAT_RDY;
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