15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * pthread_rwlock_timedrdlock.c 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Description: 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This translation unit implements read/write lock primitives. 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * -------------------------------------------------------------------------- 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Pthreads-win32 - POSIX Threads Library for Win32 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Copyright(C) 1998 John E. Bossom 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Copyright(C) 1999,2005 Pthreads-win32 contributors 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Contact Email: rpj@callisto.canberra.edu.au 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * The current list of contributors is contained 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * in the file CONTRIBUTORS included with the source 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * code distribution. The list can also be seen at the 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * following World Wide Web location: 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * http://sources.redhat.com/pthreads-win32/contributors.html 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This library is free software; you can redistribute it and/or 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * modify it under the terms of the GNU Lesser General Public 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * License as published by the Free Software Foundation; either 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * version 2 of the License, or (at your option) any later version. 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This library is distributed in the hope that it will be useful, 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * but WITHOUT ANY WARRANTY; without even the implied warranty of 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Lesser General Public License for more details. 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * You should have received a copy of the GNU Lesser General Public 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * License along with this library in the file COPYING.LIB; 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * if not, write to the Free Software Foundation, Inc., 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <limits.h> 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "pthread.h" 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "implement.h" 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)int 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)pthread_rwlock_timedrdlock (pthread_rwlock_t * rwlock, 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const struct timespec *abstime) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles){ 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int result; 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pthread_rwlock_t rwl; 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (rwlock == NULL || *rwlock == NULL) 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return EINVAL; 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * We do a quick check to see if we need to do more work 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * to initialise a static rwlock. We check 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * again inside the guarded section of ptw32_rwlock_check_need_init() 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * to avoid race conditions. 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result = ptw32_rwlock_check_need_init (rwlock); 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (result != 0 && result != EBUSY) 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return result; 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) rwl = *rwlock; 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (rwl->nMagic != PTW32_RWLOCK_MAGIC) 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return EINVAL; 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if ((result = 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pthread_mutex_timedlock (&(rwl->mtxExclusiveAccess), abstime)) != 0) 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return result; 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (++rwl->nSharedAccessCount == INT_MAX) 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if ((result = 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pthread_mutex_timedlock (&(rwl->mtxSharedAccessCompleted), 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) abstime)) != 0) 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (result == ETIMEDOUT) 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ++rwl->nCompletedSharedAccessCount; 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) (void) pthread_mutex_unlock (&(rwl->mtxExclusiveAccess)); 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return result; 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) rwl->nCompletedSharedAccessCount = 0; 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if ((result = 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pthread_mutex_unlock (&(rwl->mtxSharedAccessCompleted))) != 0) 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) (void) pthread_mutex_unlock (&(rwl->mtxExclusiveAccess)); 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return result; 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return (pthread_mutex_unlock (&(rwl->mtxExclusiveAccess))); 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 110