1 /* 2 * pthread_spin_init.c 3 * 4 * Description: 5 * This translation unit implements spin lock primitives. 6 * 7 * -------------------------------------------------------------------------- 8 * 9 * Pthreads-win32 - POSIX Threads Library for Win32 10 * Copyright(C) 1998 John E. Bossom 11 * Copyright(C) 1999,2005 Pthreads-win32 contributors 12 * 13 * Contact Email: rpj (at) callisto.canberra.edu.au 14 * 15 * The current list of contributors is contained 16 * in the file CONTRIBUTORS included with the source 17 * code distribution. The list can also be seen at the 18 * following World Wide Web location: 19 * http://sources.redhat.com/pthreads-win32/contributors.html 20 * 21 * This library is free software; you can redistribute it and/or 22 * modify it under the terms of the GNU Lesser General Public 23 * License as published by the Free Software Foundation; either 24 * version 2 of the License, or (at your option) any later version. 25 * 26 * This library is distributed in the hope that it will be useful, 27 * but WITHOUT ANY WARRANTY; without even the implied warranty of 28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 29 * Lesser General Public License for more details. 30 * 31 * You should have received a copy of the GNU Lesser General Public 32 * License along with this library in the file COPYING.LIB; 33 * if not, write to the Free Software Foundation, Inc., 34 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 35 */ 36 37 #include "pthread.h" 38 #include "implement.h" 39 40 41 int 42 pthread_spin_init (pthread_spinlock_t * lock, int pshared) 43 { 44 pthread_spinlock_t s; 45 int cpus = 0; 46 int result = 0; 47 48 if (lock == NULL) 49 { 50 return EINVAL; 51 } 52 53 if (0 != ptw32_getprocessors (&cpus)) 54 { 55 cpus = 1; 56 } 57 58 if (cpus > 1) 59 { 60 if (pshared == PTHREAD_PROCESS_SHARED) 61 { 62 /* 63 * Creating spinlock that can be shared between 64 * processes. 65 */ 66 #if _POSIX_THREAD_PROCESS_SHARED >= 0 67 68 /* 69 * Not implemented yet. 70 */ 71 72 #error ERROR [__FILE__, line __LINE__]: Process shared spin locks are not supported yet. 73 74 #else 75 76 return ENOSYS; 77 78 #endif /* _POSIX_THREAD_PROCESS_SHARED */ 79 80 } 81 } 82 83 s = (pthread_spinlock_t) calloc (1, sizeof (*s)); 84 85 if (s == NULL) 86 { 87 return ENOMEM; 88 } 89 90 if (cpus > 1) 91 { 92 s->u.cpus = cpus; 93 s->interlock = PTW32_SPIN_UNLOCKED; 94 } 95 else 96 { 97 pthread_mutexattr_t ma; 98 result = pthread_mutexattr_init (&ma); 99 100 if (0 == result) 101 { 102 ma->pshared = pshared; 103 result = pthread_mutex_init (&(s->u.mutex), &ma); 104 if (0 == result) 105 { 106 s->interlock = PTW32_SPIN_USE_MUTEX; 107 } 108 } 109 (void) pthread_mutexattr_destroy (&ma); 110 } 111 112 if (0 == result) 113 { 114 *lock = s; 115 } 116 else 117 { 118 (void) free (s); 119 *lock = NULL; 120 } 121 122 return (result); 123 } 124
