Home | History | Annotate | Line # | Download | only in gen
_errno.c revision 1.9.2.1 
      1 /*	$NetBSD: _errno.c,v 1.9.2.1 2001/08/08 18:29:50 nathanw Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by J.T. Conklin.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include "reentrant.h"
     40 #include <errno.h>
     41 #include <stdlib.h>
     42 
     43 #undef errno
     44 extern int errno;
     45 
     46 #ifdef _REENTRANT
     47 static thread_key_t __errno_key;
     48 static once_t __errno_key_once = ONCE_INITIALIZER;
     49 
     50 static void
     51 __errno_key_setup(void)
     52 {
     53 	thr_keycreate(&__errno_key, free);
     54 }
     55 #endif
     56 
     57 int *
     58 __errno(void)
     59 {
     60 #ifdef _REENTRANT
     61 	int *eaddr;
     62 	extern int __isthreaded;
     63 
     64 	if (__isthreaded == 0)
     65 		return &errno;
     66 	thr_once(&__errno_key_once, __errno_key_setup);
     67 	eaddr = thr_getspecific(__errno_key);
     68 	if (eaddr == NULL) {
     69 		eaddr = malloc(sizeof(int));
     70 		if (eaddr == NULL)
     71 			return &errno;
     72 		thr_setspecific(__errno_key, eaddr);
     73 	}
     74 	return eaddr;
     75 #else
     76 	return &errno;
     77 #endif
     78 }
     79