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 * $Id: uthread_fork.c,v 1.10 1999/06/20 08:28:23 jb Exp $
40 #include "pthread_private.h"
48 pthread_t pthread_save;
51 * Defer signals to protect the scheduling queues from access
52 * by the signal handler:
54 _thread_kern_sig_defer();
56 /* Fork a new process: */
57 if ((ret = _thread_sys_fork()) != 0) {
58 /* Parent process or error. Nothing to do here. */
60 /* Close the pthread kernel pipe: */
61 _thread_sys_close(_thread_kern_pipe[0]);
62 _thread_sys_close(_thread_kern_pipe[1]);
64 /* Reset signals pending for the running thread: */
65 _thread_run->sigpend = 0;
68 * Create a pipe that is written to by the signal handler to
69 * prevent signals being missed in calls to
72 if (_thread_sys_pipe(_thread_kern_pipe) != 0) {
73 /* Cannot create pipe, so abort: */
74 PANIC("Cannot create pthread kernel pipe for forked process");
76 /* Get the flags for the read pipe: */
77 else if ((flags = _thread_sys_fcntl(_thread_kern_pipe[0], F_GETFL, NULL)) == -1) {
78 /* Abort this application: */
81 /* Make the read pipe non-blocking: */
82 else if (_thread_sys_fcntl(_thread_kern_pipe[0], F_SETFL, flags | O_NONBLOCK) == -1) {
83 /* Abort this application: */
86 /* Get the flags for the write pipe: */
87 else if ((flags = _thread_sys_fcntl(_thread_kern_pipe[1], F_GETFL, NULL)) == -1) {
88 /* Abort this application: */
91 /* Make the write pipe non-blocking: */
92 else if (_thread_sys_fcntl(_thread_kern_pipe[1], F_SETFL, flags | O_NONBLOCK) == -1) {
93 /* Abort this application: */
96 /* Reinitialize the GC mutex: */
97 else if (_mutex_reinit(&_gc_mutex) != 0) {
98 /* Abort this application: */
99 PANIC("Cannot initialize GC mutex for forked process");
101 /* Reinitialize the GC condition variable: */
102 else if (_cond_reinit(&_gc_cond) != 0) {
103 /* Abort this application: */
104 PANIC("Cannot initialize GC condvar for forked process");
106 /* Initialize the ready queue: */
107 else if (_pq_init(&_readyq) != 0) {
108 /* Abort this application: */
109 PANIC("Cannot initialize priority ready queue.");
112 * Enter a loop to remove all threads other than
113 * the running thread from the thread list:
115 pthread = TAILQ_FIRST(&_thread_list);
116 while (pthread != NULL) {
117 /* Save the thread to be freed: */
118 pthread_save = pthread;
121 * Advance to the next thread before
122 * destroying the current thread:
124 pthread = TAILQ_NEXT(pthread, dle);
126 /* Make sure this isn't the running thread: */
127 if (pthread_save != _thread_run) {
128 /* Remove this thread from the list: */
129 TAILQ_REMOVE(&_thread_list,
132 if (pthread_save->attr.stackaddr_attr ==
133 NULL && pthread_save->stack != NULL)
135 * Free the stack of the
138 free(pthread_save->stack);
140 if (pthread_save->specific_data != NULL)
141 free(pthread_save->specific_data);
143 if (pthread_save->poll_data.fds != NULL)
144 free(pthread_save->poll_data.fds);
150 /* Re-init the dead thread list: */
151 TAILQ_INIT(&_dead_list);
153 /* Re-init the waiting and work queues. */
154 TAILQ_INIT(&_waitingq);
157 /* Re-init the threads mutex queue: */
158 TAILQ_INIT(&_thread_run->mutexq);
160 /* No spinlocks yet: */
161 _spinblock_count = 0;
163 /* Don't queue signals yet: */
166 /* Initialize signal handling: */
169 /* Initialize the scheduling switch hook routine: */
170 _sched_switch_hook = NULL;
172 /* Clear out any locks in the file descriptor table: */
173 for (i = 0; i < _thread_dtablesize; i++) {
174 if (_thread_fd_table[i] != NULL) {
175 /* Initialise the file locks: */
176 memset(&_thread_fd_table[i]->lock, 0,
177 sizeof(_thread_fd_table[i]->lock));
178 _thread_fd_table[i]->r_owner = NULL;
179 _thread_fd_table[i]->w_owner = NULL;
180 _thread_fd_table[i]->r_fname = NULL;
181 _thread_fd_table[i]->w_fname = NULL;
182 _thread_fd_table[i]->r_lineno = 0;;
183 _thread_fd_table[i]->w_lineno = 0;;
184 _thread_fd_table[i]->r_lockcount = 0;;
185 _thread_fd_table[i]->w_lockcount = 0;;
187 /* Initialise the read/write queues: */
188 TAILQ_INIT(&_thread_fd_table[i]->r_queue);
189 TAILQ_INIT(&_thread_fd_table[i]->w_queue);
196 * Undefer and handle pending signals, yielding if necessary:
198 _thread_kern_sig_undefer();
200 /* Return the process ID: */