os_q.src

UCOS在51上的移植,绝对经典！可以较少开发人员的工作量

; *                 will no longer be guarded by the queue.
; *              5) If the storage for the message queue was allocated dynamically (i.e. using a malloc()
; *                 type call) then your application MUST release the memory storage by call the counterpart
; *                 call of the dynamic allocation scheme used.  If the queue storage was created statically
; *                 then, the storage can be reused.
; *********************************************************************************************************
; */
; 
; #if OS_Q_DEL_EN > 0
; OS_EVENT  *OSQDel (OS_EVENT *pevent, INT8U opt, INT8U *err)LG_REENTRANT
; {
; #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                  = (OS_Q *)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                  = (OS_Q *)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                   */
; 
;         default:
;              OS_EXIT_CRITICAL();
;              *err = OS_ERR_INVALID_OPT;
;              return (pevent);
;     }
; }
; #endif
; 
; /*$PAGE*/
; /*
; *********************************************************************************************************
; *                                           FLUSH QUEUE
; *
; * Description : This function is used to flush the contents of the message queue.
; *
; * Arguments   : none
; *
; * Returns     : OS_NO_ERR           upon success
; *               OS_ERR_EVENT_TYPE   If you didn't pass a pointer to a queue
; *               OS_ERR_PEVENT_NULL  If 'pevent' is a NULL pointer
; *********************************************************************************************************
; */
; 
; #if OS_Q_FLUSH_EN > 0
; INT8U  OSQFlush (OS_EVENT *pevent)LG_REENTRANT
; {
; #if OS_CRITICAL_METHOD == 3                           /* Allocate storage for CPU status register      */
;     OS_CPU_SR  cpu_sr;
; #endif
;     OS_Q      *pq;
; 
; 
; #if OS_ARG_CHK_EN > 0
;     if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
;         return (OS_ERR_PEVENT_NULL);
;     }
;     if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */
;         return (OS_ERR_EVENT_TYPE);
;     }
; #endif
;     OS_ENTER_CRITICAL();
;     pq             = (OS_Q *)pevent->OSEventPtr;      /* Point to queue storage structure              */
;     pq->OSQIn      = pq->OSQStart;
;     pq->OSQOut     = pq->OSQStart;
;     pq->OSQEntries = 0;
;     OS_EXIT_CRITICAL();
;     return (OS_NO_ERR);
; }
; #endif
; 
; /*$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
; *                            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)LG_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();
;     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;
;         OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; /* No longer waiting for event                        */
;         OS_EXIT_CRITICAL();
;         *err                    = OS_NO_ERR;
;         return (msg);                            /* Return message received                            */
;     }
;     OS_EventTO(pevent);                          /* Timed out                                          */
;     OS_EXIT_CRITICAL();
;     *err = OS_TIMEOUT;                           /* Indicate a timeout occured                         */
;     return ((void *)0);                          /* No message received                                */
; }
; /*$PAGE*/
; /*
; *********************************************************************************************************
; *                                        POST MESSAGE TO A QUEUE
; *
; * Description: This function sends a message to a queue
; *
; * Arguments  : pevent        is a pointer to the event control block associated with the desired queue
; *
; *              msg           is a pointer to the message to send.  You MUST NOT send a NULL pointer.
; *
; * Returns    : OS_NO_ERR             The call was successful and the message was sent
; *              OS_Q_FULL             If the queue cannot accept any more messages because it is full.
; *              OS_ERR_EVENT_TYPE     If you didn't pass a pointer to a queue.
; *              OS_ERR_PEVENT_NULL    If 'pevent' is a NULL pointer
; *              OS_ERR_POST_NULL_PTR  If you are attempting to post a NULL pointer
; *********************************************************************************************************
; */
; 
; #if OS_Q_POST_EN > 0
; INT8U  OSQPost (OS_EVENT *pevent, void *msg)LG_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 (msg == (void *)0) {                           /* Make sure we are not posting a NULL pointer   */
;         return (OS_ERR_POST_NULL_PTR);
;     }
;     if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */
;         return (OS_ERR_EVENT_TYPE);
;     }
; #endif
;     OS_ENTER_CRITICAL();
;     if (pevent->OSEventGrp != 0x00) {                 /* See if any task pending on queue              */
;         OS_EventTaskRdy(pevent, msg, OS_STAT_Q);      /* Ready highest priority task waiting on event  */
;         OS_EXIT_CRITICAL();
;         OS_Sched();                                   /* Find highest priority task ready to run       */
;         return (OS_NO_ERR);
;     }
;     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_Q_FULL);
;     }
;     *pq->OSQIn++ = msg;                               /* 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_NO_ERR);
; }
; #endif
; /*$PAGE*/
; /*
; *********************************************************************************************************
; *                                   POST MESSAGE TO THE FRONT OF A QUEUE
; *
; * Description: This function sends a message to a queue but unlike OSQPost(), the message is posted at
; *              the front instead of the end of the queue.  Using OSQPostFront() allows you to send
; *              'priority' messages.
; *
; * Arguments  : pevent        is a pointer to the event control block associated with the desired queue
; *
; *              msg           is a pointer to the message to send.  You MUST NOT send a NULL pointer.