/*
* 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: [email protected]
*
* 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 ()).p == NULL)
{
/*
* Yikes! unable to allocate a thread!
* Throw an exception? return an error?
*/
result = &reallyBad;
}
else
{
result = (int *)(&self.p->exitStatus);
}
return (result);
} /* _errno */
#endif /* (NEED_ERRNO) */