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/*
* errno.c
*
* Description:
* This translation unit implements routines associated with spawning a new
* thread.
*
* Pthreads-win32 - POSIX Threads Library for Win32
* Copyright (C) 1998
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA
*/
#if (! defined(HAVE_ERRNO)) || (! defined( _REENTRANT ) && ! defined( _MT ))
#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 there 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 /* (! HAVE_ERRNO) || (!_REENTRANT && !_MT) */