text: /*
   * 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) 1999,2003 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) */
  
  