📄 os_mbox.lst
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166 2 } else {
167 2 tasks_waiting = FALSE; /* No */
168 2 }
169 1 switch (opt) {
170 2 case OS_DEL_NO_PEND: /* Delete mailbox only if no task waiting */
171 2 if (tasks_waiting == FALSE) {
172 3 pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
173 3 pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */
174 3 OSEventFreeList = pevent; /* Get next free event control block */
175 3 OS_EXIT_CRITICAL();
176 3 *err = OS_NO_ERR;
177 3 return ((OS_EVENT *)0); /* Mailbox has been deleted */
178 3 } else {
C51 COMPILER V8.02 OS_MBOX 05/22/2008 18:01:51 PAGE 4
179 3 OS_EXIT_CRITICAL();
180 3 *err = OS_ERR_TASK_WAITING;
181 3 return (pevent);
182 3 }
183 2
184 2 case OS_DEL_ALWAYS: /* Always delete the mailbox */
185 2 while (pevent->OSEventGrp != 0x00) { /* Ready ALL tasks waiting for mailbox */
186 3 OS_EventTaskRdy(pevent, (void *)0, OS_STAT_MBOX);
187 3 }
188 2 pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
189 2 pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */
190 2 OSEventFreeList = pevent; /* Get next free event control block */
191 2 OS_EXIT_CRITICAL();
192 2 if (tasks_waiting == TRUE) { /* Reschedule only if task(s) were waiting */
193 3 OS_Sched(); /* Find highest priority task ready to run */
194 3 }
195 2 *err = OS_NO_ERR;
196 2 return ((OS_EVENT *)0); /* Mailbox has been deleted */
197 2
198 2 default:
199 2 OS_EXIT_CRITICAL();
200 2 *err = OS_ERR_INVALID_OPT;
201 2 return (pevent);
202 2 }
203 1 }
204 #endif
205
206 /*$PAGE*/
207 /*
208 *********************************************************************************************************
209 * PEND ON MAILBOX FOR A MESSAGE
210 *
211 * Description: This function waits for a message to be sent to a mailbox
212 *
213 * Arguments : pevent is a pointer to the event control block associated with the desired mailbox
214 *
215 * timeout is an optional timeout period (in clock ticks). If non-zero, your task will
216 * wait for a message to arrive at the mailbox up to the amount of time
217 * specified by this argument. If you specify 0, however, your task will wait
218 * forever at the specified mailbox or, until a message arrives.
219 *
220 * err is a pointer to where an error message will be deposited. Possible error
221 * messages are:
222 *
223 * OS_NO_ERR The call was successful and your task received a
224 * message.
225 * OS_TIMEOUT A message was not received within the specified timeout
226 * OS_ERR_EVENT_TYPE Invalid event type
227 * OS_ERR_PEND_ISR If you called this function from an ISR and the result
228 * would lead to a suspension.
229 * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer
230 *
231 * Returns : != (void *)0 is a pointer to the message received
232 * == (void *)0 if no message was received or,
233 * if 'pevent' is a NULL pointer or,
234 * if you didn't pass the proper pointer to the event control block.
235 *********************************************************************************************************
236 */
237
238 void *OSMboxPend (OS_EVENT *pevent, INT16U timeout, INT8U *err) KCREENTRANT
239 {
240 1 #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
C51 COMPILER V8.02 OS_MBOX 05/22/2008 18:01:51 PAGE 5
241 1 OS_CPU_SR cpu_sr;
242 1 #endif
243 1 void *msg;
244 1
245 1
246 1 if (OSIntNesting > 0) { /* See if called from ISR ... */
247 2 *err = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
248 2 return ((void *)0);
249 2 }
250 1 #if OS_ARG_CHK_EN > 0
251 1 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
252 2 *err = OS_ERR_PEVENT_NULL;
253 2 return ((void *)0);
254 2 }
255 1 if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */
256 2 *err = OS_ERR_EVENT_TYPE;
257 2 return ((void *)0);
258 2 }
259 1 #endif
260 1 OS_ENTER_CRITICAL();
261 1 msg = pevent->OSEventPtr;
262 1 if (msg != (void *)0) { /* See if there is already a message */
263 2 pevent->OSEventPtr = (void *)0; /* Clear the mailbox */
264 2 OS_EXIT_CRITICAL();
265 2 *err = OS_NO_ERR;
266 2 return (msg); /* Return the message received (or NULL) */
267 2 }
268 1 OSTCBCur->OSTCBStat |= OS_STAT_MBOX; /* Message not available, task will pend */
269 1 OSTCBCur->OSTCBDly = timeout; /* Load timeout in TCB */
270 1 OS_EventTaskWait(pevent); /* Suspend task until event or timeout occurs */
271 1 OS_EXIT_CRITICAL();
272 1 OS_Sched(); /* Find next highest priority task ready to run */
273 1 OS_ENTER_CRITICAL();
274 1 msg = OSTCBCur->OSTCBMsg;
275 1 if (msg != (void *)0) { /* See if we were given the message */
276 2 OSTCBCur->OSTCBMsg = (void *)0; /* Yes, clear message received */
277 2 OSTCBCur->OSTCBStat = OS_STAT_RDY;
278 2 OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; /* No longer waiting for event */
279 2 OS_EXIT_CRITICAL();
280 2 *err = OS_NO_ERR;
281 2 return (msg); /* Return the message received */
282 2 }
283 1 OS_EventTO(pevent); /* Timed out, Make task ready */
284 1 OS_EXIT_CRITICAL();
285 1 *err = OS_TIMEOUT; /* Indicate that a timeout occured */
286 1 return ((void *)0); /* Return a NULL message */
287 1 }
288 /*$PAGE*/
289 /*
290 *********************************************************************************************************
291 * POST MESSAGE TO A MAILBOX
292 *
293 * Description: This function sends a message to a mailbox
294 *
295 * Arguments : pevent is a pointer to the event control block associated with the desired mailbox
296 *
297 * msg is a pointer to the message to send. You MUST NOT send a NULL pointer.
298 *
299 * Returns : OS_NO_ERR The call was successful and the message was sent
300 * OS_MBOX_FULL If the mailbox already contains a message. You can can only send one
301 * message at a time and thus, the message MUST be consumed before you
302 * are allowed to send another one.
C51 COMPILER V8.02 OS_MBOX 05/22/2008 18:01:51 PAGE 6
303 * OS_ERR_EVENT_TYPE If you are attempting to post to a non mailbox.
304 * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer
305 * OS_ERR_POST_NULL_PTR If you are attempting to post a NULL pointer
306 *********************************************************************************************************
307 */
308
309 #if OS_MBOX_POST_EN > 0
310 INT8U OSMboxPost (OS_EVENT *pevent, void *msg) KCREENTRANT
311 {
312 1 #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
313 1 OS_CPU_SR cpu_sr;
314 1 #endif
315 1
316 1
317 1 #if OS_ARG_CHK_EN > 0
318 1 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
319 2 return (OS_ERR_PEVENT_NULL);
320 2 }
321 1 if (msg == (void *)0) { /* Make sure we are not posting a NULL pointer */
322 2 return (OS_ERR_POST_NULL_PTR);
323 2 }
324 1 if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */
325 2 return (OS_ERR_EVENT_TYPE);
326 2 }
327 1 #endif
328 1 OS_ENTER_CRITICAL();
329 1 if (pevent->OSEventGrp != 0x00) { /* See if any task pending on mailbox */
330 2 OS_EventTaskRdy(pevent, msg, OS_STAT_MBOX); /* Ready highest priority task waiting on event */
331 2 OS_EXIT_CRITICAL();
332 2 OS_Sched(); /* Find highest priority task ready to run */
333 2 return (OS_NO_ERR);
334 2 }
335 1 if (pevent->OSEventPtr != (void *)0) { /* Make sure mailbox doesn't already have a msg */
336 2 OS_EXIT_CRITICAL();
337 2 return (OS_MBOX_FULL);
338 2 }
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