usr/src/lib/libc/port/gen/sh_locks.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include "lint.h"
  30 #include <mtlib.h>
  31 #include <sys/types.h>
  32 #include <synch.h>
  33 #include <thread.h>
  34 #include <pthread.h>
  35 #include "libc.h"
  36
  37 /*
  38  * fork1-safety.
  39  * These three routines were used to make some libc interfaces fork1-safe.
  40  * With the merge of libthread into libc, almost all libc internal-only
  41  * locks are acquired via lmutex_lock() or lrw_rdlock()/lrw_wrlock(),
  42  * which makes them automatically fork1-safe (as well as async-signal
  43  * safe), so these functions are now used only for the locks that cannot
  44  * be used with lmutex_lock or lrw_rdlock()/lrw_wrlock().
  45  */
  46
  47 extern void atexit_locks(void);
  48 extern void atexit_unlocks(void);
  49
  50 extern void stdio_locks(void);
  51 extern void stdio_unlocks(void);
  52
  53 extern void malloc_locks(void);
  54 extern void malloc_unlocks(void);
  55
  56 static void
  57 libc_prepare_atfork(void)
  58 {
  59         atexit_locks();
  60         stdio_locks();
  61         malloc_locks();
  62 }
  63
  64 static void
  65 libc_child_atfork(void)
  66 {
  67         malloc_unlocks();
  68         stdio_unlocks();
  69         atexit_unlocks();
  70 }
  71
  72 static void
  73 libc_parent_atfork(void)
  74 {
  75         malloc_unlocks();
  76         stdio_unlocks();
  77         atexit_unlocks();
  78 }
  79
  80 /* called from libc_init() */
  81 void
  82 atfork_init(void)
  83 {
  84         (void) pthread_atfork(libc_prepare_atfork,
  85             libc_parent_atfork, libc_child_atfork);
  86 }