15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pthread_cond_destroy.c 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Description: 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This translation unit implements condition variables and their primitives. 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * -------------------------------------------------------------------------- 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Pthreads-win32 - POSIX Threads Library for Win32 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Copyright(C) 1998 John E. Bossom 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Copyright(C) 1999,2005 Pthreads-win32 contributors 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Contact Email: rpj@callisto.canberra.edu.au 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * The current list of contributors is contained 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * in the file CONTRIBUTORS included with the source 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * code distribution. The list can also be seen at the 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * following World Wide Web location: 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * http://sources.redhat.com/pthreads-win32/contributors.html 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This library is free software; you can redistribute it and/or 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * modify it under the terms of the GNU Lesser General Public 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * License as published by the Free Software Foundation; either 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * version 2 of the License, or (at your option) any later version. 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This library is distributed in the hope that it will be useful, 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * but WITHOUT ANY WARRANTY; without even the implied warranty of 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Lesser General Public License for more details. 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * You should have received a copy of the GNU Lesser General Public 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * License along with this library in the file COPYING.LIB; 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * if not, write to the Free Software Foundation, Inc., 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "pthread.h" 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "implement.h" 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)int 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)pthread_cond_destroy (pthread_cond_t * cond) 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ------------------------------------------------------ 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * DOCPUBLIC 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This function destroys a condition variable 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * PARAMETERS 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * cond 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pointer to an instance of pthread_cond_t 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * DESCRIPTION 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This function destroys a condition variable. 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * NOTES: 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 1) A condition variable can be destroyed 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * immediately after all the threads that 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * are blocked on it are awakened. e.g. 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * struct list { 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pthread_mutex_t lm; 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ... 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * } 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * struct elt { 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * key k; 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * int busy; 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pthread_cond_t notbusy; 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ... 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * } 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * struct elt * 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * list_find(struct list *lp, key k) 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * { 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * struct elt *ep; 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pthread_mutex_lock(&lp->lm); 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * while ((ep = find_elt(l,k) != NULL) && ep->busy) 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pthread_cond_wait(&ep->notbusy, &lp->lm); 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * if (ep != NULL) 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ep->busy = 1; 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pthread_mutex_unlock(&lp->lm); 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * return(ep); 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * } 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * delete_elt(struct list *lp, struct elt *ep) 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * { 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pthread_mutex_lock(&lp->lm); 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * assert(ep->busy); 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ... remove ep from list ... 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ep->busy = 0; 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * (A) pthread_cond_broadcast(&ep->notbusy); 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pthread_mutex_unlock(&lp->lm); 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * (B) pthread_cond_destroy(&rp->notbusy); 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * free(ep); 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * } 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * In this example, the condition variable 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * and its list element may be freed (line B) 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * immediately after all threads waiting for 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * it are awakened (line A), since the mutex 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * and the code ensure that no other thread 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * can touch the element to be deleted. 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * RESULTS 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 0 successfully released condition variable, 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * EINVAL 'cond' is invalid, 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * EBUSY 'cond' is in use, 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ------------------------------------------------------ 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles){ 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pthread_cond_t cv; 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int result = 0, result1 = 0, result2 = 0; 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Assuming any race condition here is harmless. 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (cond == NULL || *cond == NULL) 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return EINVAL; 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (*cond != PTHREAD_COND_INITIALIZER) 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_local_node_t node; 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_lock_acquire(&ptw32_cond_list_lock, &node); 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) cv = *cond; 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Close the gate; this will synchronize this thread with 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * all already signaled waiters to let them retract their 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * waiter status - SEE NOTE 1 ABOVE!!! 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (ptw32_semwait (&(cv->semBlockLock)) != 0) /* Non-cancelable */ 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result = errno; 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 1445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 1465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * !TRY! lock mtxUnblockLock; try will detect busy condition 1475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * and will not cause a deadlock with respect to concurrent 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * signal/broadcast. 1495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if ((result = pthread_mutex_trylock (&(cv->mtxUnblockLock))) != 0) 1515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) (void) sem_post (&(cv->semBlockLock)); 1535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (result != 0) 1575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_lock_release(&node); 1595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return result; 1605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 1635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Check whether cv is still busy (still has waiters) 1645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (cv->nWaitersBlocked > cv->nWaitersGone) 1665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (sem_post (&(cv->semBlockLock)) != 0) 1685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result = errno; 1705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result1 = pthread_mutex_unlock (&(cv->mtxUnblockLock)); 1725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result2 = EBUSY; 1735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 1755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 1775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Now it is safe to destroy 1785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) *cond = NULL; 1805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (sem_destroy (&(cv->semBlockLock)) != 0) 1825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result = errno; 1845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (sem_destroy (&(cv->semBlockQueue)) != 0) 1865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result1 = errno; 1885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if ((result2 = pthread_mutex_unlock (&(cv->mtxUnblockLock))) == 0) 1905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result2 = pthread_mutex_destroy (&(cv->mtxUnblockLock)); 1925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* Unlink the CV from the list */ 1955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (ptw32_cond_list_head == cv) 1975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_cond_list_head = cv->next; 1995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 2015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 2025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) cv->prev->next = cv->next; 2035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (ptw32_cond_list_tail == cv) 2065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 2075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_cond_list_tail = cv->prev; 2085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 2105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 2115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) cv->next->prev = cv->prev; 2125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) (void) free (cv); 2155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_lock_release(&node); 2185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 2205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 2215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_local_node_t node; 2225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 2235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * See notes in ptw32_cond_check_need_init() above also. 2245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 2255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_lock_acquire(&ptw32_cond_test_init_lock, &node); 2265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 2285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Check again. 2295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 2305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (*cond == PTHREAD_COND_INITIALIZER) 2315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 2325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 2335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This is all we need to do to destroy a statically 2345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * initialised cond that has not yet been used (initialised). 2355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * If we get to here, another thread waiting to initialise 2365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * this cond will get an EINVAL. That's OK. 2375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 2385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) *cond = NULL; 2395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 2415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 2425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 2435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * The cv has been initialised while we were waiting 2445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * so assume it's in use. 2455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 2465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result = EBUSY; 2475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_lock_release(&node); 2505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return ((result != 0) ? result : ((result1 != 0) ? result1 : result2)); 2535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 254