📄 os_mbox.lst
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tasks_waiting = FALSE; /* No */
}
switch (opt) {
case OS_DEL_NO_PEND: /* Delete mailbox only if no task waiting */
if (tasks_waiting == FALSE) {
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); /* Mailbox has been deleted */
} else {
OS_EXIT_CRITICAL();
*err = OS_ERR_TASK_WAITING;
return (pevent);
}
case OS_DEL_ALWAYS: /* Always delete the mailbox */
while (pevent->OSEventGrp != 0x00) { /* Ready ALL tasks waiting for mailbox */
C51 COMPILER V8.08 OS_MBOX 03/02/2009 10:42:36 PAGE 4
OS_EventTaskRdy(pevent, (void *)0, OS_STAT_MBOX);
}
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); /* Mailbox has been deleted */
default:
OS_EXIT_CRITICAL();
*err = OS_ERR_INVALID_OPT;
return (pevent);
}
}
#endif
198
199 /*$PAGE*/
200 /*
201 *********************************************************************************************************
202 * PEND ON MAILBOX FOR A MESSAGE
203 *
204 * Description: This function waits for a message to be sent to a mailbox
205 *
206 * Arguments : pevent is a pointer to the event control block associated with the desired mailbox
207 *
208 * timeout is an optional timeout period (in clock ticks). If non-zero, your task will
209 * wait for a message to arrive at the mailbox up to the amount of time
210 * specified by this argument. If you specify 0, however, your task will wait
211 * forever at the specified mailbox or, until a message arrives.
212 *
213 * err is a pointer to where an error message will be deposited. Possible error
214 * messages are:
215 *
216 * OS_NO_ERR The call was successful and your task received a
217 * message.
218 * OS_TIMEOUT A message was not received within the specified timeout
219 * OS_ERR_EVENT_TYPE Invalid event type
220 * OS_ERR_PEND_ISR If you called this function from an ISR and the result
221 * would lead to a suspension.
222 * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer
223 *
224 * Returns : != (void *)0 is a pointer to the message received
225 * == (void *)0 if no message was received or,
226 * if 'pevent' is a NULL pointer or,
227 * if you didn't pass the proper pointer to the event control block.
228 *********************************************************************************************************
229 */
230
231 void *OSMboxPend (OS_EVENT *pevent, INT16U timeout, INT8U *err)reentrant
232 {
233 1
234 1 void *msg;
235 1
236 1
237 1 if (OSIntNesting > 0) { /* See if called from ISR ... */
238 2 *err = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
239 2 return ((void *)0);
240 2 }
C51 COMPILER V8.08 OS_MBOX 03/02/2009 10:42:36 PAGE 5
241 1 #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_MBOX) { /* Validate event block type */
*err = OS_ERR_EVENT_TYPE;
return ((void *)0);
}
#endif
251 1 OS_ENTER_CRITICAL();
252 1 msg = pevent->OSEventPtr;
253 1 if (msg != (void *)0) { /* See if there is already a message */
254 2 pevent->OSEventPtr = (void *)0; /* Clear the mailbox */
255 2 OS_EXIT_CRITICAL();
256 2 *err = OS_NO_ERR;
257 2 return (msg); /* Return the message received (or NULL) */
258 2 }
259 1 OSTCBCur->OSTCBStat |= OS_STAT_MBOX; /* Message not available, task will pend */
260 1 OSTCBCur->OSTCBDly = timeout; /* Load timeout in TCB */
261 1 OS_EventTaskWait(pevent); /* Suspend task until event or timeout occurs */
262 1 OS_EXIT_CRITICAL();
263 1 OS_Sched(); /* Find next highest priority task ready to run */
264 1 OS_ENTER_CRITICAL();
265 1 msg = OSTCBCur->OSTCBMsg;
266 1 if (msg != (void *)0) { /* See if we were given the message */
267 2 OSTCBCur->OSTCBMsg = (void *)0; /* Yes, clear message received */
268 2 OSTCBCur->OSTCBStat = OS_STAT_RDY;
269 2 OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; /* No longer waiting for event */
270 2 OS_EXIT_CRITICAL();
271 2 *err = OS_NO_ERR;
272 2 return (msg); /* Return the message received */
273 2 }
274 1 OS_EventTO(pevent); /* Timed out, Make task ready */
275 1 OS_EXIT_CRITICAL();
276 1 *err = OS_TIMEOUT; /* Indicate that a timeout occured */
277 1 return ((void *)0); /* Return a NULL message */
278 1 }
279 /*$PAGE*/
280 /*
281 *********************************************************************************************************
282 * POST MESSAGE TO A MAILBOX
283 *
284 * Description: This function sends a message to a mailbox
285 *
286 * Arguments : pevent is a pointer to the event control block associated with the desired mailbox
287 *
288 * msg is a pointer to the message to send. You MUST NOT send a NULL pointer.
289 *
290 * Returns : OS_NO_ERR The call was successful and the message was sent
291 * OS_MBOX_FULL If the mailbox already contains a message. You can can only send one
292 * message at a time and thus, the message MUST be consumed before you
293 * are allowed to send another one.
294 * OS_ERR_EVENT_TYPE If you are attempting to post to a non mailbox.
295 * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer
296 * OS_ERR_POST_NULL_PTR If you are attempting to post a NULL pointer
297 *********************************************************************************************************
298 */
299
300 #if OS_MBOX_POST_EN > 0
301 INT8U OSMboxPost (OS_EVENT *pevent, void *msg)reentrant
302 {
C51 COMPILER V8.08 OS_MBOX 03/02/2009 10:42:36 PAGE 6
303 1
304 1
305 1
306 1 #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_MBOX) { /* Validate event block type */
return (OS_ERR_EVENT_TYPE);
}
#endif
317 1 OS_ENTER_CRITICAL();
318 1 if (pevent->OSEventGrp != 0x00) { /* See if any task pending on mailbox */
319 2 OS_EventTaskRdy(pevent, msg, OS_STAT_MBOX); /* Ready highest priority task waiting on event */
320 2 OS_EXIT_CRITICAL();
321 2 OS_Sched(); /* Find highest priority task ready to run */
322 2 return (OS_NO_ERR);
323 2 }
324 1 if (pevent->OSEventPtr != (void *)0) { /* Make sure mailbox doesn't already have a msg */
325 2 OS_EXIT_CRITICAL();
326 2 return (OS_MBOX_FULL);
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