/src/compiler/ucos-vs2008/UCOS_SIM/src/ucosii/os_mutex.c
C | 603 lines | 390 code | 34 blank | 179 comment | 94 complexity | 09fbeec509c78b1996a94780188c5569 MD5 | raw file
1/* 2********************************************************************************************************* 3* uC/OS-II 4* The Real-Time Kernel 5* MUTUAL EXCLUSION SEMAPHORE MANAGEMENT 6* 7* (c) Copyright 1992-2005, Jean J. Labrosse, Weston, FL 8* All Rights Reserved 9* 10* File : OS_MUTEX.C 11* By : Jean J. Labrosse 12* Version : V2.80 13********************************************************************************************************* 14*/ 15 16#ifndef OS_MASTER_FILE 17#include <ucos_ii.h> 18#endif 19 20/* 21********************************************************************************************************* 22* LOCAL CONSTANTS 23********************************************************************************************************* 24*/ 25 26#define OS_MUTEX_KEEP_LOWER_8 0x00FFu 27#define OS_MUTEX_KEEP_UPPER_8 0xFF00u 28 29#define OS_MUTEX_AVAILABLE 0x00FFu 30 31 32#if OS_MUTEX_EN > 0 33/* 34********************************************************************************************************* 35* ACCEPT MUTUAL EXCLUSION SEMAPHORE 36* 37* Description: This function checks the mutual exclusion semaphore to see if a resource is available. 38* Unlike OSMutexPend(), OSMutexAccept() does not suspend the calling task if the resource is 39* not available or the event did not occur. 40* 41* Arguments : pevent is a pointer to the event control block 42* 43* err is a pointer to an error code which will be returned to your application: 44* OS_NO_ERR if the call was successful. 45* OS_ERR_EVENT_TYPE if 'pevent' is not a pointer to a mutex 46* OS_ERR_PEVENT_NULL 'pevent' is a NULL pointer 47* OS_ERR_PEND_ISR if you called this function from an ISR 48* 49* Returns : == 1 if the resource is available, the mutual exclusion semaphore is acquired 50* == 0 a) if the resource is not available 51* b) you didn't pass a pointer to a mutual exclusion semaphore 52* c) you called this function from an ISR 53* 54* Warning(s) : This function CANNOT be called from an ISR because mutual exclusion semaphores are 55* intended to be used by tasks only. 56********************************************************************************************************* 57*/ 58 59#if OS_MUTEX_ACCEPT_EN > 0 60INT8U OSMutexAccept (OS_EVENT *pevent, INT8U *err) 61{ 62#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ 63 OS_CPU_SR cpu_sr = 0; 64#endif 65 66 67 68#if OS_ARG_CHK_EN > 0 69 if (err == (INT8U *)0) { /* Validate 'err' */ 70 return (0); 71 } 72 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */ 73 *err = OS_ERR_PEVENT_NULL; 74 return (0); 75 } 76#endif 77 if (pevent->OSEventType != OS_EVENT_TYPE_MUTEX) { /* Validate event block type */ 78 *err = OS_ERR_EVENT_TYPE; 79 return (0); 80 } 81 if (OSIntNesting > 0) { /* Make sure it's not called from an ISR */ 82 *err = OS_ERR_PEND_ISR; 83 return (0); 84 } 85 OS_ENTER_CRITICAL(); /* Get value (0 or 1) of Mutex */ 86 if ((pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8) == OS_MUTEX_AVAILABLE) { 87 pevent->OSEventCnt &= OS_MUTEX_KEEP_UPPER_8; /* Mask off LSByte (Acquire Mutex) */ 88 pevent->OSEventCnt |= OSTCBCur->OSTCBPrio; /* Save current task priority in LSByte */ 89 pevent->OSEventPtr = (void *)OSTCBCur; /* Link TCB of task owning Mutex */ 90 OS_EXIT_CRITICAL(); 91 *err = OS_NO_ERR; 92 return (1); 93 } 94 OS_EXIT_CRITICAL(); 95 *err = OS_NO_ERR; 96 return (0); 97} 98#endif 99 100/*$PAGE*/ 101/* 102********************************************************************************************************* 103* CREATE A MUTUAL EXCLUSION SEMAPHORE 104* 105* Description: This function creates a mutual exclusion semaphore. 106* 107* Arguments : prio is the priority to use when accessing the mutual exclusion semaphore. In 108* other words, when the semaphore is acquired and a higher priority task 109* attempts to obtain the semaphore then the priority of the task owning the 110* semaphore is raised to this priority. It is assumed that you will specify 111* a priority that is LOWER in value than ANY of the tasks competing for the 112* mutex. 113* 114* err is a pointer to an error code which will be returned to your application: 115* OS_NO_ERR if the call was successful. 116* OS_ERR_CREATE_ISR if you attempted to create a MUTEX from an ISR 117* OS_PRIO_EXIST if a task at the priority inheritance priority 118* already exist. 119* OS_ERR_PEVENT_NULL No more event control blocks available. 120* OS_PRIO_INVALID if the priority you specify is higher that the 121* maximum allowed (i.e. > OS_LOWEST_PRIO) 122* 123* Returns : != (void *)0 is a pointer to the event control clock (OS_EVENT) associated with the 124* created mutex. 125* == (void *)0 if an error is detected. 126* 127* Note(s) : 1) The LEAST significant 8 bits of '.OSEventCnt' are used to hold the priority number 128* of the task owning the mutex or 0xFF if no task owns the mutex. 129* 2) The MOST significant 8 bits of '.OSEventCnt' are used to hold the priority number 130* to use to reduce priority inversion. 131********************************************************************************************************* 132*/ 133 134OS_EVENT *OSMutexCreate (INT8U prio, INT8U *err) 135{ 136 OS_EVENT *pevent; 137#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ 138 OS_CPU_SR cpu_sr = 0; 139#endif 140 141 142 143#if OS_ARG_CHK_EN > 0 144 if (err == (INT8U *)0) { /* Validate 'err' */ 145 return ((OS_EVENT *)0); 146 } 147 if (prio >= OS_LOWEST_PRIO) { /* Validate PIP */ 148 *err = OS_PRIO_INVALID; 149 return ((OS_EVENT *)0); 150 } 151#endif 152 if (OSIntNesting > 0) { /* See if called from ISR ... */ 153 *err = OS_ERR_CREATE_ISR; /* ... can't CREATE mutex from an ISR */ 154 return ((OS_EVENT *)0); 155 } 156 OS_ENTER_CRITICAL(); 157 if (OSTCBPrioTbl[prio] != (OS_TCB *)0) { /* Mutex priority must not already exist */ 158 OS_EXIT_CRITICAL(); /* Task already exist at priority ... */ 159 *err = OS_PRIO_EXIST; /* ... inheritance priority */ 160 return ((OS_EVENT *)0); 161 } 162 OSTCBPrioTbl[prio] = (OS_TCB *)1; /* Reserve the table entry */ 163 pevent = OSEventFreeList; /* Get next free event control block */ 164 if (pevent == (OS_EVENT *)0) { /* See if an ECB was available */ 165 OSTCBPrioTbl[prio] = (OS_TCB *)0; /* No, Release the table entry */ 166 OS_EXIT_CRITICAL(); 167 *err = OS_ERR_PEVENT_NULL; /* No more event control blocks */ 168 return (pevent); 169 } 170 OSEventFreeList = (OS_EVENT *)OSEventFreeList->OSEventPtr; /* Adjust the free list */ 171 OS_EXIT_CRITICAL(); 172 pevent->OSEventType = OS_EVENT_TYPE_MUTEX; 173 pevent->OSEventCnt = (INT16U)((INT16U)prio << 8) | OS_MUTEX_AVAILABLE; /* Resource is avail. */ 174 pevent->OSEventPtr = (void *)0; /* No task owning the mutex */ 175#if OS_EVENT_NAME_SIZE > 1 176 pevent->OSEventName[0] = '?'; 177 pevent->OSEventName[1] = OS_ASCII_NUL; 178#endif 179 OS_EventWaitListInit(pevent); 180 *err = OS_NO_ERR; 181 return (pevent); 182} 183 184/*$PAGE*/ 185/* 186********************************************************************************************************* 187* DELETE A MUTEX 188* 189* Description: This function deletes a mutual exclusion semaphore and readies all tasks pending on the it. 190* 191* Arguments : pevent is a pointer to the event control block associated with the desired mutex. 192* 193* opt determines delete options as follows: 194* opt == OS_DEL_NO_PEND Delete mutex ONLY if no task pending 195* opt == OS_DEL_ALWAYS Deletes the mutex even if tasks are waiting. 196* In this case, all the tasks pending will be readied. 197* 198* err is a pointer to an error code that can contain one of the following values: 199* OS_NO_ERR The call was successful and the mutex was deleted 200* OS_ERR_DEL_ISR If you attempted to delete the MUTEX from an ISR 201* OS_ERR_INVALID_OPT An invalid option was specified 202* OS_ERR_TASK_WAITING One or more tasks were waiting on the mutex 203* OS_ERR_EVENT_TYPE If you didn't pass a pointer to a mutex 204* OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer. 205* 206* Returns : pevent upon error 207* (OS_EVENT *)0 if the mutex was successfully deleted. 208* 209* Note(s) : 1) This function must be used with care. Tasks that would normally expect the presence of 210* the mutex MUST check the return code of OSMutexPend(). 211* 2) This call can potentially disable interrupts for a long time. The interrupt disable 212* time is directly proportional to the number of tasks waiting on the mutex. 213* 3) Because ALL tasks pending on the mutex will be readied, you MUST be careful because the 214* resource(s) will no longer be guarded by the mutex. 215********************************************************************************************************* 216*/ 217 218#if OS_MUTEX_DEL_EN 219OS_EVENT *OSMutexDel (OS_EVENT *pevent, INT8U opt, INT8U *err) 220{ 221 BOOLEAN tasks_waiting; 222 OS_EVENT *pevent_return; 223 INT8U pip; 224#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ 225 OS_CPU_SR cpu_sr = 0; 226#endif 227 228 229 230#if OS_ARG_CHK_EN > 0 231 if (err == (INT8U *)0) { /* Validate 'err' */ 232 return ((OS_EVENT *)0); 233 } 234 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */ 235 *err = OS_ERR_PEVENT_NULL; 236 return ((OS_EVENT *)0); 237 } 238#endif 239 if (pevent->OSEventType != OS_EVENT_TYPE_MUTEX) { /* Validate event block type */ 240 *err = OS_ERR_EVENT_TYPE; 241 return (pevent); 242 } 243 if (OSIntNesting > 0) { /* See if called from ISR ... */ 244 *err = OS_ERR_DEL_ISR; /* ... can't DELETE from an ISR */ 245 return (pevent); 246 } 247 OS_ENTER_CRITICAL(); 248 if (pevent->OSEventGrp != 0) { /* See if any tasks waiting on mutex */ 249 tasks_waiting = TRUE; /* Yes */ 250 } else { 251 tasks_waiting = FALSE; /* No */ 252 } 253 switch (opt) { 254 case OS_DEL_NO_PEND: /* Delete mutex only if no task waiting */ 255 if (tasks_waiting == FALSE) { 256#if OS_EVENT_NAME_SIZE > 1 257 pevent->OSEventName[0] = '?'; /* Unknown name */ 258 pevent->OSEventName[1] = OS_ASCII_NUL; 259#endif 260 pip = (INT8U)(pevent->OSEventCnt >> 8); 261 OSTCBPrioTbl[pip] = (OS_TCB *)0; /* Free up the PIP */ 262 pevent->OSEventType = OS_EVENT_TYPE_UNUSED; 263 pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */ 264 pevent->OSEventCnt = 0; 265 OSEventFreeList = pevent; 266 OS_EXIT_CRITICAL(); 267 *err = OS_NO_ERR; 268 pevent_return = (OS_EVENT *)0; /* Mutex has been deleted */ 269 } else { 270 OS_EXIT_CRITICAL(); 271 *err = OS_ERR_TASK_WAITING; 272 pevent_return = pevent; 273 } 274 break; 275 276 case OS_DEL_ALWAYS: /* Always delete the mutex */ 277 while (pevent->OSEventGrp != 0) { /* Ready ALL tasks waiting for mutex */ 278 (void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_MUTEX); 279 } 280#if OS_EVENT_NAME_SIZE > 1 281 pevent->OSEventName[0] = '?'; /* Unknown name */ 282 pevent->OSEventName[1] = OS_ASCII_NUL; 283#endif 284 pip = (INT8U)(pevent->OSEventCnt >> 8); 285 OSTCBPrioTbl[pip] = (OS_TCB *)0; /* Free up the PIP */ 286 pevent->OSEventType = OS_EVENT_TYPE_UNUSED; 287 pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */ 288 pevent->OSEventCnt = 0; 289 OSEventFreeList = pevent; /* Get next free event control block */ 290 OS_EXIT_CRITICAL(); 291 if (tasks_waiting == TRUE) { /* Reschedule only if task(s) were waiting */ 292 OS_Sched(); /* Find highest priority task ready to run */ 293 } 294 *err = OS_NO_ERR; 295 pevent_return = (OS_EVENT *)0; /* Mutex has been deleted */ 296 break; 297 298 default: 299 OS_EXIT_CRITICAL(); 300 *err = OS_ERR_INVALID_OPT; 301 pevent_return = pevent; 302 break; 303 } 304 return (pevent_return); 305} 306#endif 307 308/*$PAGE*/ 309/* 310********************************************************************************************************* 311* PEND ON MUTUAL EXCLUSION SEMAPHORE 312* 313* Description: This function waits for a mutual exclusion semaphore. 314* 315* Arguments : pevent is a pointer to the event control block associated with the desired 316* mutex. 317* 318* timeout is an optional timeout period (in clock ticks). If non-zero, your task will 319* wait for the resource up to the amount of time specified by this argument. 320* If you specify 0, however, your task will wait forever at the specified 321* mutex or, until the resource becomes available. 322* 323* err is a pointer to where an error message will be deposited. Possible error 324* messages are: 325* OS_NO_ERR The call was successful and your task owns the mutex 326* OS_TIMEOUT The mutex was not available within the specified time. 327* OS_ERR_EVENT_TYPE If you didn't pass a pointer to a mutex 328* OS_ERR_PEVENT_NULL 'pevent' is a NULL pointer 329* OS_ERR_PEND_ISR If you called this function from an ISR and the result 330* would lead to a suspension. 331* OS_ERR_PIP_LOWER If the priority of the task that owns the Mutex is 332* HIGHER (i.e. a lower number) than the PIP. This error 333* indicates that you did not set the PIP higher (lower 334* number) than ALL the tasks that compete for the Mutex. 335* Unfortunately, this is something that could not be 336* detected when the Mutex is created because we don't know 337* what tasks will be using the Mutex. 338* 339* Returns : none 340* 341* Note(s) : 1) The task that owns the Mutex MUST NOT pend on any other event while it owns the mutex. 342* 2) You MUST NOT change the priority of the task that owns the mutex 343********************************************************************************************************* 344*/ 345void OSMutexPend (OS_EVENT *pevent, INT16U timeout, INT8U *err) 346{ 347 INT8U pip; /* Priority Inheritance Priority (PIP) */ 348 INT8U mprio; /* Mutex owner priority */ 349 BOOLEAN rdy; /* Flag indicating task was ready */ 350 OS_TCB *ptcb; 351 OS_EVENT *pevent2; 352 INT8U y; 353#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ 354 OS_CPU_SR cpu_sr = 0; 355#endif 356 357 358 359#if OS_ARG_CHK_EN > 0 360 if (err == (INT8U *)0) { /* Validate 'err' */ 361 return; 362 } 363 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */ 364 *err = OS_ERR_PEVENT_NULL; 365 return; 366 } 367#endif 368 if (pevent->OSEventType != OS_EVENT_TYPE_MUTEX) { /* Validate event block type */ 369 *err = OS_ERR_EVENT_TYPE; 370 return; 371 } 372 if (OSIntNesting > 0) { /* See if called from ISR ... */ 373 *err = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */ 374 return; 375 } 376 OS_ENTER_CRITICAL(); 377 pip = (INT8U)(pevent->OSEventCnt >> 8); /* Get PIP from mutex */ 378 /* Is Mutex available? */ 379 if ((INT8U)(pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8) == OS_MUTEX_AVAILABLE) { 380 pevent->OSEventCnt &= OS_MUTEX_KEEP_UPPER_8; /* Yes, Acquire the resource */ 381 pevent->OSEventCnt |= OSTCBCur->OSTCBPrio; /* Save priority of owning task */ 382 pevent->OSEventPtr = (void *)OSTCBCur; /* Point to owning task's OS_TCB */ 383 if (OSTCBCur->OSTCBPrio <= pip) { /* PIP 'must' have a SMALLER prio ... */ 384 OS_EXIT_CRITICAL(); /* ... than current task! */ 385 *err = OS_ERR_PIP_LOWER; 386 } else { 387 OS_EXIT_CRITICAL(); 388 *err = OS_NO_ERR; 389 } 390 return; 391 } 392 mprio = (INT8U)(pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8); /* No, Get priority of mutex owner */ 393 ptcb = (OS_TCB *)(pevent->OSEventPtr); /* Point to TCB of mutex owner */ 394 if (ptcb->OSTCBPrio > pip) { /* Need to promote prio of owner?*/ 395 if (mprio > OSTCBCur->OSTCBPrio) { 396 y = ptcb->OSTCBY; 397 if ((OSRdyTbl[y] & ptcb->OSTCBBitX) != 0) { /* See if mutex owner is ready */ 398 OSRdyTbl[y] &= ~ptcb->OSTCBBitX; /* Yes, Remove owner from Rdy ...*/ 399 if (OSRdyTbl[y] == 0) { /* ... list at current prio */ 400 OSRdyGrp &= ~ptcb->OSTCBBitY; 401 } 402 rdy = TRUE; 403 } else { 404 pevent2 = ptcb->OSTCBEventPtr; 405 if (pevent2 != (OS_EVENT *)0) { /* Remove from event wait list */ 406 if ((pevent2->OSEventTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0) { 407 pevent2->OSEventGrp &= ~ptcb->OSTCBBitY; 408 } 409 } 410 rdy = FALSE; /* No */ 411 } 412 ptcb->OSTCBPrio = pip; /* Change owner task prio to PIP */ 413#if OS_LOWEST_PRIO <= 63 414 ptcb->OSTCBY = ptcb->OSTCBPrio >> 3; 415 ptcb->OSTCBX = ptcb->OSTCBPrio & 0x07; 416#else 417 ptcb->OSTCBY = (ptcb->OSTCBPrio >> 4) & 0xFF; 418 ptcb->OSTCBX = ptcb->OSTCBPrio & 0x0F; 419#endif 420 ptcb->OSTCBBitY = 1 << ptcb->OSTCBY; 421 ptcb->OSTCBBitX = 1 << ptcb->OSTCBX; 422 if (rdy == TRUE) { /* If task was ready at owner's priority ...*/ 423 OSRdyGrp |= ptcb->OSTCBBitY; /* ... make it ready at new priority. */ 424 OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX; 425 } else { 426 pevent2 = ptcb->OSTCBEventPtr; 427 if (pevent2 != (OS_EVENT *)0) { /* Remove from event wait list */ 428 pevent2->OSEventGrp |= ptcb->OSTCBBitY; 429 pevent2->OSEventTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX; 430 } 431 } 432 OSTCBPrioTbl[pip] = ptcb; 433 } 434 } 435 OSTCBCur->OSTCBStat |= OS_STAT_MUTEX; /* Mutex not available, pend current task */ 436 OSTCBCur->OSTCBPendTO = FALSE; 437 OSTCBCur->OSTCBDly = timeout; /* Store timeout in current task's TCB */ 438 OS_EventTaskWait(pevent); /* Suspend task until event or timeout occurs */ 439 OS_EXIT_CRITICAL(); 440 OS_Sched(); /* Find next highest priority task ready */ 441 OS_ENTER_CRITICAL(); 442 if (OSTCBCur->OSTCBPendTO == TRUE) { /* See if we timed out during the pend */ 443 OS_EventTO(pevent); 444 OS_EXIT_CRITICAL(); 445 *err = OS_TIMEOUT; /* Indicate that we didn't get mutex within TO */ 446 return; 447 } 448 OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; 449 OS_EXIT_CRITICAL(); 450 *err = OS_NO_ERR; 451} 452/*$PAGE*/ 453/* 454********************************************************************************************************* 455* POST TO A MUTUAL EXCLUSION SEMAPHORE 456* 457* Description: This function signals a mutual exclusion semaphore 458* 459* Arguments : pevent is a pointer to the event control block associated with the desired 460* mutex. 461* 462* Returns : OS_NO_ERR The call was successful and the mutex was signaled. 463* OS_ERR_EVENT_TYPE If you didn't pass a pointer to a mutex 464* OS_ERR_PEVENT_NULL 'pevent' is a NULL pointer 465* OS_ERR_POST_ISR Attempted to post from an ISR (not valid for MUTEXes) 466* OS_ERR_NOT_MUTEX_OWNER The task that did the post is NOT the owner of the MUTEX. 467********************************************************************************************************* 468*/ 469 470INT8U OSMutexPost (OS_EVENT *pevent) 471{ 472 INT8U pip; /* Priority inheritance priority */ 473 INT8U prio; 474 INT8U y; 475#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ 476 OS_CPU_SR cpu_sr = 0; 477#endif 478 479 480 481 if (OSIntNesting > 0) { /* See if called from ISR ... */ 482 return (OS_ERR_POST_ISR); /* ... can't POST mutex from an ISR */ 483 } 484#if OS_ARG_CHK_EN > 0 485 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */ 486 return (OS_ERR_PEVENT_NULL); 487 } 488#endif 489 if (pevent->OSEventType != OS_EVENT_TYPE_MUTEX) { /* Validate event block type */ 490 return (OS_ERR_EVENT_TYPE); 491 } 492 OS_ENTER_CRITICAL(); 493 pip = (INT8U)(pevent->OSEventCnt >> 8); /* Get priority inheritance priority of mutex */ 494 prio = (INT8U)(pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8); /* Get owner's original priority */ 495 if (OSTCBCur != (OS_TCB *)pevent->OSEventPtr) { /* See if posting task owns the MUTEX */ 496 OS_EXIT_CRITICAL(); 497 return (OS_ERR_NOT_MUTEX_OWNER); 498 } 499 if (OSTCBCur->OSTCBPrio == pip) { /* Did we have to raise current task's priority? */ 500 y = OSTCBCur->OSTCBY; /* Yes, Return to original priority */ 501 OSRdyTbl[y] &= ~OSTCBCur->OSTCBBitX; /* Remove owner from ready list at 'pip' */ 502 if (OSRdyTbl[y] == 0) { 503 OSRdyGrp &= ~OSTCBCur->OSTCBBitY; 504 } 505 OSTCBCur->OSTCBPrio = prio; 506#if OS_LOWEST_PRIO <= 63 507 OSTCBCur->OSTCBY = prio >> 3; 508 OSTCBCur->OSTCBX = prio & 0x07; 509#else 510 OSTCBCur->OSTCBY = (prio >> 4) & 0xFF; 511 OSTCBCur->OSTCBX = prio & 0x0F; 512#endif 513 OSTCBCur->OSTCBBitY = 1 << OSTCBCur->OSTCBY; 514 OSTCBCur->OSTCBBitX = 1 << OSTCBCur->OSTCBX; 515 OSRdyGrp |= OSTCBCur->OSTCBBitY; 516 OSRdyTbl[OSTCBCur->OSTCBY] |= OSTCBCur->OSTCBBitX; 517 OSTCBPrioTbl[prio] = OSTCBCur; 518 } 519 OSTCBPrioTbl[pip] = (OS_TCB *)1; /* Reserve table entry */ 520 if (pevent->OSEventGrp != 0) { /* Any task waiting for the mutex? */ 521 /* Yes, Make HPT waiting for mutex ready */ 522 prio = OS_EventTaskRdy(pevent, (void *)0, OS_STAT_MUTEX); 523 pevent->OSEventCnt &= OS_MUTEX_KEEP_UPPER_8; /* Save priority of mutex's new owner */ 524 pevent->OSEventCnt |= prio; 525 pevent->OSEventPtr = OSTCBPrioTbl[prio]; /* Link to mutex owner's OS_TCB */ 526 OS_EXIT_CRITICAL(); 527 OS_Sched(); /* Find highest priority task ready to run */ 528 return (OS_NO_ERR); 529 } 530 pevent->OSEventCnt |= OS_MUTEX_AVAILABLE; /* No, Mutex is now available */ 531 pevent->OSEventPtr = (void *)0; 532 OS_EXIT_CRITICAL(); 533 return (OS_NO_ERR); 534} 535/*$PAGE*/ 536/* 537********************************************************************************************************* 538* QUERY A MUTUAL EXCLUSION SEMAPHORE 539* 540* Description: This function obtains information about a mutex 541* 542* Arguments : pevent is a pointer to the event control block associated with the desired mutex 543* 544* p_mutex_data is a pointer to a structure that will contain information about the mutex 545* 546* Returns : OS_NO_ERR The call was successful and the message was sent 547* OS_ERR_QUERY_ISR If you called this function from an ISR 548* OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer 549* OS_ERR_PDATA_NULL If 'p_mutex_data' is a NULL pointer 550* OS_ERR_EVENT_TYPE If you are attempting to obtain data from a non mutex. 551********************************************************************************************************* 552*/ 553 554#if OS_MUTEX_QUERY_EN > 0 555INT8U OSMutexQuery (OS_EVENT *pevent, OS_MUTEX_DATA *p_mutex_data) 556{ 557 INT8U i; 558#if OS_LOWEST_PRIO <= 63 559 INT8U *psrc; 560 INT8U *pdest; 561#else 562 INT16U *psrc; 563 INT16U *pdest; 564#endif 565#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ 566 OS_CPU_SR cpu_sr = 0; 567#endif 568 569 570 571 if (OSIntNesting > 0) { /* See if called from ISR ... */ 572 return (OS_ERR_QUERY_ISR); /* ... can't QUERY mutex from an ISR */ 573 } 574#if OS_ARG_CHK_EN > 0 575 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */ 576 return (OS_ERR_PEVENT_NULL); 577 } 578 if (p_mutex_data == (OS_MUTEX_DATA *)0) { /* Validate 'p_mutex_data' */ 579 return (OS_ERR_PDATA_NULL); 580 } 581#endif 582 if (pevent->OSEventType != OS_EVENT_TYPE_MUTEX) { /* Validate event block type */ 583 return (OS_ERR_EVENT_TYPE); 584 } 585 OS_ENTER_CRITICAL(); 586 p_mutex_data->OSMutexPIP = (INT8U)(pevent->OSEventCnt >> 8); 587 p_mutex_data->OSOwnerPrio = (INT8U)(pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8); 588 if (p_mutex_data->OSOwnerPrio == 0xFF) { 589 p_mutex_data->OSValue = 1; 590 } else { 591 p_mutex_data->OSValue = 0; 592 } 593 p_mutex_data->OSEventGrp = pevent->OSEventGrp; /* Copy wait list */ 594 psrc = &pevent->OSEventTbl[0]; 595 pdest = &p_mutex_data->OSEventTbl[0]; 596 for (i = 0; i < OS_EVENT_TBL_SIZE; i++) { 597 *pdest++ = *psrc++; 598 } 599 OS_EXIT_CRITICAL(); 600 return (OS_NO_ERR); 601} 602#endif /* OS_MUTEX_QUERY_EN */ 603#endif /* OS_MUTEX_EN */