2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $FreeBSD: src/lib/libc_r/uthread/uthread_fork.c,v 1.19.2.7 2002/10/22 14:44:03 fjoe Exp $
33 * $DragonFly: src/lib/libc_r/uthread/uthread_fork.c,v 1.6 2008/05/25 21:34:49 hasso Exp $
41 #include "pthread_private.h"
46 struct pthread *curthread = _get_curthread();
47 struct pthread_atfork *af;
51 pthread_t pthread_save;
54 * Defer signals to protect the scheduling queues from access
55 * by the signal handler:
57 _thread_kern_sig_defer();
59 _pthread_mutex_lock(&_atfork_mutex);
61 /* Run down atfork prepare handlers. */
62 TAILQ_FOREACH_REVERSE(af, &_atfork_list, atfork_head, qe) {
63 if (af->prepare != NULL)
67 /* Fork a new process: */
68 if ((ret = __sys_fork()) != 0) {
69 /* Run down atfork parent handlers. */
70 TAILQ_FOREACH(af, &_atfork_list, qe) {
71 if (af->parent != NULL)
74 _pthread_mutex_unlock(&_atfork_mutex);
76 /* Close the pthread kernel pipe: */
77 __sys_close(_thread_kern_pipe[0]);
78 __sys_close(_thread_kern_pipe[1]);
80 /* Reset signals pending for the running thread: */
81 sigemptyset(&curthread->sigpend);
85 /* Reinitialize the GC mutex: */
86 if (_mutex_reinit(&_gc_mutex) != 0) {
87 /* Abort this application: */
88 PANIC("Cannot initialize GC mutex for forked process");
90 /* Reinitialize the GC condition variable: */
91 else if (_cond_reinit(&_gc_cond) != 0) {
92 /* Abort this application: */
93 PANIC("Cannot initialize GC condvar for forked process");
95 /* Initialize the ready queue: */
96 else if (_pq_init(&_readyq) != 0) {
97 /* Abort this application: */
98 PANIC("Cannot initialize priority ready queue.");
101 * Enter a loop to remove all threads other than
102 * the running thread from the thread list:
104 pthread = TAILQ_FIRST(&_thread_list);
105 while (pthread != NULL) {
106 /* Save the thread to be freed: */
107 pthread_save = pthread;
110 * Advance to the next thread before
111 * destroying the current thread:
113 pthread = TAILQ_NEXT(pthread, tle);
115 /* Make sure this isn't the running thread: */
116 if (pthread_save != curthread) {
117 /* Remove this thread from the list: */
118 TAILQ_REMOVE(&_thread_list,
121 if (pthread_save->attr.stackaddr_attr ==
122 NULL && pthread_save->stack != NULL) {
123 if (pthread_save->attr.stacksize_attr
124 == PTHREAD_STACK_DEFAULT) {
126 * Default-size stack.
129 struct stack *spare_stack;
132 = (pthread_save->stack
133 + PTHREAD_STACK_DEFAULT
134 - sizeof(struct stack));
135 SLIST_INSERT_HEAD(&_stackq,
142 free(pthread_save->stack);
145 if (pthread_save->specific_data != NULL)
146 free(pthread_save->specific_data);
148 if (pthread_save->poll_data.fds != NULL)
149 free(pthread_save->poll_data.fds);
151 _rtld_free_tls(pthread_save->tcb);
156 /* Treat the current thread as the initial thread: */
157 _thread_initial = curthread;
159 /* Re-init the dead thread list: */
160 TAILQ_INIT(&_dead_list);
162 /* Re-init the waiting and work queues. */
163 TAILQ_INIT(&_waitingq);
166 /* Re-init the threads mutex queue: */
167 TAILQ_INIT(&curthread->mutexq);
169 /* No spinlocks yet: */
170 _spinblock_count = 0;
172 /* Don't queue signals yet: */
175 /* Initialize the scheduling switch hook routine: */
176 _sched_switch_hook = NULL;
178 /* Clear out any locks in the file descriptor table: */
179 for (i = 0; i < _thread_dtablesize; i++) {
180 if (_thread_fd_table[i] != NULL) {
181 /* Initialise the file locks: */
182 memset(&_thread_fd_table[i]->lock, 0,
183 sizeof(_thread_fd_table[i]->lock));
184 _thread_fd_table[i]->r_owner = NULL;
185 _thread_fd_table[i]->w_owner = NULL;
186 _thread_fd_table[i]->r_fname = NULL;
187 _thread_fd_table[i]->w_fname = NULL;
188 _thread_fd_table[i]->r_lineno = 0;
189 _thread_fd_table[i]->w_lineno = 0;
190 _thread_fd_table[i]->r_lockcount = 0;
191 _thread_fd_table[i]->w_lockcount = 0;
193 /* Initialise the read/write queues: */
194 TAILQ_INIT(&_thread_fd_table[i]->r_queue);
195 TAILQ_INIT(&_thread_fd_table[i]->w_queue);
199 /* Run down atfork child handlers. */
200 TAILQ_FOREACH(af, &_atfork_list, qe) {
201 if (af->child != NULL)
204 _mutex_reinit(&_atfork_mutex);
208 * Undefer and handle pending signals, yielding if necessary:
210 _thread_kern_sig_undefer();
212 /* Return the process ID: */
216 __strong_reference(_fork, fork);