1 /* 2 * errno.c 3 * 4 * Description: 5 * This translation unit implements routines associated with spawning a new 6 * thread. 7 * 8 * -------------------------------------------------------------------------- 9 * 10 * Pthreads-win32 - POSIX Threads Library for Win32 11 * Copyright(C) 1998 John E. Bossom 12 * Copyright(C) 1999,2005 Pthreads-win32 contributors 13 * 14 * Contact Email: rpj (at) callisto.canberra.edu.au 15 * 16 * The current list of contributors is contained 17 * in the file CONTRIBUTORS included with the source 18 * code distribution. The list can also be seen at the 19 * following World Wide Web location: 20 * http://sources.redhat.com/pthreads-win32/contributors.html 21 * 22 * This library is free software; you can redistribute it and/or 23 * modify it under the terms of the GNU Lesser General Public 24 * License as published by the Free Software Foundation; either 25 * version 2 of the License, or (at your option) any later version. 26 * 27 * This library is distributed in the hope that it will be useful, 28 * but WITHOUT ANY WARRANTY; without even the implied warranty of 29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 30 * Lesser General Public License for more details. 31 * 32 * You should have received a copy of the GNU Lesser General Public 33 * License along with this library in the file COPYING.LIB; 34 * if not, write to the Free Software Foundation, Inc., 35 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 36 */ 37 38 #if defined(NEED_ERRNO) 39 40 #include "pthread.h" 41 #include "implement.h" 42 43 static int reallyBad = ENOMEM; 44 45 /* 46 * Re-entrant errno. 47 * 48 * Each thread has it's own errno variable in pthread_t. 49 * 50 * The benefit of using the pthread_t structure 51 * instead of another TSD key is TSD keys are limited 52 * on Win32 to 64 per process. Secondly, to implement 53 * it properly without using pthread_t you'd need 54 * to dynamically allocate an int on starting the thread 55 * and store it manually into TLS and then ensure that you free 56 * it on thread termination. We get all that for free 57 * by simply storing the errno on the pthread_t structure. 58 * 59 * MSVC and Mingw32 already have their own thread-safe errno. 60 * 61 * #if defined( _REENTRANT ) || defined( _MT ) 62 * #define errno *_errno() 63 * 64 * int *_errno( void ); 65 * #else 66 * extern int errno; 67 * #endif 68 * 69 */ 70 71 int * 72 _errno (void) 73 { 74 pthread_t self; 75 int *result; 76 77 if ((self = pthread_self ()).p == NULL) 78 { 79 /* 80 * Yikes! unable to allocate a thread! 81 * Throw an exception? return an error? 82 */ 83 result = &reallyBad; 84 } 85 else 86 { 87 result = (int *)(&self.p->exitStatus); 88 } 89 90 return (result); 91 92 } /* _errno */ 93 94 #endif /* (NEED_ERRNO) */ 95