1 /* 2 * pthread_key_create.c 3 * 4 * Description: 5 * POSIX thread functions which implement thread-specific data (TSD). 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 /* TLS_OUT_OF_INDEXES not defined on WinCE */ 42 #if !defined(TLS_OUT_OF_INDEXES) 43 #define TLS_OUT_OF_INDEXES 0xffffffff 44 #endif 45 46 int 47 pthread_key_create (pthread_key_t * key, void (PTW32_CDECL *destructor) (void *)) 48 /* 49 * ------------------------------------------------------ 50 * DOCPUBLIC 51 * This function creates a thread-specific data key visible 52 * to all threads. All existing and new threads have a value 53 * NULL for key until set using pthread_setspecific. When any 54 * thread with a non-NULL value for key terminates, 'destructor' 55 * is called with key's current value for that thread. 56 * 57 * PARAMETERS 58 * key 59 * pointer to an instance of pthread_key_t 60 * 61 * 62 * DESCRIPTION 63 * This function creates a thread-specific data key visible 64 * to all threads. All existing and new threads have a value 65 * NULL for key until set using pthread_setspecific. When any 66 * thread with a non-NULL value for key terminates, 'destructor' 67 * is called with key's current value for that thread. 68 * 69 * RESULTS 70 * 0 successfully created semaphore, 71 * EAGAIN insufficient resources or PTHREAD_KEYS_MAX 72 * exceeded, 73 * ENOMEM insufficient memory to create the key, 74 * 75 * ------------------------------------------------------ 76 */ 77 { 78 int result = 0; 79 pthread_key_t newkey; 80 81 if ((newkey = (pthread_key_t) calloc (1, sizeof (*newkey))) == NULL) 82 { 83 result = ENOMEM; 84 } 85 else if ((newkey->key = TlsAlloc ()) == TLS_OUT_OF_INDEXES) 86 { 87 result = EAGAIN; 88 89 free (newkey); 90 newkey = NULL; 91 } 92 else if (destructor != NULL) 93 { 94 /* 95 * Have to manage associations between thread and key; 96 * Therefore, need a lock that allows competing threads 97 * to gain exclusive access to the key->threads list. 98 * 99 * The mutex will only be created when it is first locked. 100 */ 101 newkey->keyLock = 0; 102 newkey->destructor = destructor; 103 } 104 105 *key = newkey; 106 107 return (result); 108 } 109
