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/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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* or http://www.opensolaris.org/os/licensing.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information: Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*/
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/*
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* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
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* Use is subject to license terms.
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*/
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#pragma ident "%Z%%M% %I% %E% SMI"
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#include "thr_uberdata.h"
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#include "mtlib.h"
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/*
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* fork handlers are run in LIFO order.
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* The libc fork handler is expected to be the first handler installed,
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* hence would be the last fork handler run in preparation for fork1().
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* It is essential that this be so, for other libraries depend on libc
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* and may grab their own locks before calling into libc. By special
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* arrangement, the loader runs libc's init section (libc_init()) first.
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*/
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/*
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* pthread_atfork(): installs handlers to be called during fork1().
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* There is no POSIX API that provides for deletion of atfork handlers.
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* Collaboration between the loader and libc ensures that atfork
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* handlers installed by a library are deleted when that library
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* is unloaded (see _preexec_atfork_unload() in atexit.c).
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*/
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#pragma weak _private_pthread_atfork = _pthread_atfork
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#pragma weak pthread_atfork = _pthread_atfork
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int
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_pthread_atfork(void (*prepare)(void),
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void (*parent)(void), void (*child)(void))
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{
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ulwp_t *self = curthread;
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uberdata_t *udp = self->ul_uberdata;
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atfork_t *atfp;
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atfork_t *head;
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int error;
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if ((error = fork_lock_enter("pthread_atfork")) != 0) {
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/*
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* Cannot call pthread_atfork() from a fork handler.
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*/
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fork_lock_exit();
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return (error);
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}
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if ((atfp = lmalloc(sizeof (atfork_t))) == NULL) {
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fork_lock_exit();
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return (ENOMEM);
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}
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atfp->prepare = prepare;
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atfp->parent = parent;
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atfp->child = child;
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if ((head = udp->atforklist) == NULL) {
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udp->atforklist = atfp;
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atfp->forw = atfp->back = atfp;
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} else {
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head->back->forw = atfp;
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atfp->forw = head;
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atfp->back = head->back;
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head->back = atfp;
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}
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fork_lock_exit();
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return (0);
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}
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/*
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* _prefork_handler() is called by fork1() before it starts processing.
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* It executes the user installed "prepare" routines in LIFO order (POSIX)
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*/
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void
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_prefork_handler(void)
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{
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uberdata_t *udp = curthread->ul_uberdata;
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atfork_t *atfork_q;
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atfork_t *atfp;
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if ((atfork_q = udp->atforklist) != NULL) {
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atfp = atfork_q = atfork_q->back;
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do {
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if (atfp->prepare)
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(*atfp->prepare)();
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} while ((atfp = atfp->back) != atfork_q);
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}
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}
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/*
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* _postfork_parent_handler() is called by fork1() after it retuns as parent.
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* It executes the user installed "parent" routines in FIFO order (POSIX).
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*/
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void
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_postfork_parent_handler(void)
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{
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uberdata_t *udp = curthread->ul_uberdata;
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atfork_t *atfork_q;
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atfork_t *atfp;
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if ((atfork_q = udp->atforklist) != NULL) {
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atfp = atfork_q;
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do {
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if (atfp->parent)
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(*atfp->parent)();
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} while ((atfp = atfp->forw) != atfork_q);
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}
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}
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/*
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* _postfork_child_handler() is called by fork1() after it returns as child.
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* It executes the user installed "child" routines in FIFO order (POSIX).
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*/
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void
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_postfork_child_handler(void)
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{
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uberdata_t *udp = curthread->ul_uberdata;
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atfork_t *atfork_q;
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atfork_t *atfp;
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if ((atfork_q = udp->atforklist) != NULL) {
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atfp = atfork_q;
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do {
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if (atfp->child)
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(*atfp->child)();
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} while ((atfp = atfp->forw) != atfork_q);
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}
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}
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