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Diffstat (limited to 'pthreads/errno.c')
-rw-r--r-- | pthreads/errno.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/pthreads/errno.c b/pthreads/errno.c new file mode 100644 index 000000000..9998bb8d5 --- /dev/null +++ b/pthreads/errno.c @@ -0,0 +1,94 @@ +/* + * errno.c + * + * Description: + * This translation unit implements routines associated with spawning a new + * thread. + * + * -------------------------------------------------------------------------- + * + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2005 Pthreads-win32 contributors + * + * Contact Email: rpj@callisto.canberra.edu.au + * + * The current list of contributors is contained + * in the file CONTRIBUTORS included with the source + * code distribution. The list can also be seen at the + * following World Wide Web location: + * http://sources.redhat.com/pthreads-win32/contributors.html + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library in the file COPYING.LIB; + * if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#if defined(NEED_ERRNO) + +#include "pthread.h" +#include "implement.h" + +static int reallyBad = ENOMEM; + +/* + * Re-entrant errno. + * + * Each thread has it's own errno variable in pthread_t. + * + * The benefit of using the pthread_t structure + * instead of another TSD key is TSD keys are limited + * on Win32 to 64 per process. Secondly, to implement + * it properly without using pthread_t you'd need + * to dynamically allocate an int on starting the thread + * and store it manually into TLS and then ensure that you free + * it on thread termination. We get all that for free + * by simply storing the errno on the pthread_t structure. + * + * MSVC and Mingw32 already have their own thread-safe errno. + * + * #if defined( _REENTRANT ) || defined( _MT ) + * #define errno *_errno() + * + * int *_errno( void ); + * #else + * extern int errno; + * #endif + * + */ + +int * +_errno (void) +{ + pthread_t self; + int *result; + + if ((self = pthread_self ()) == NULL) + { + /* + * Yikes! unable to allocate a thread! + * Throw an exception? return an error? + */ + result = &reallyBad; + } + else + { + result = &(self->ptErrno); + } + + return (result); + +} /* _errno */ + +#endif /* (NEED_ERRNO) */ |