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/* $OpenBSD: uthread_fork.c,v 1.19 2008/04/04 19:30:41 kurt Exp $ */
/*
* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: uthread_fork.c,v 1.14 1999/09/29 15:18:38 marcel Exp $
*/
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
pid_t _dofork(int vfork);
pid_t
fork(void)
{
pid_t pid;
struct pthread_atfork *af;
/*
* Defer signals to protect the scheduling queues from access
* by the signal handler:
*/
_thread_kern_sig_defer();
pthread_mutex_lock(&_atfork_mutex);
/* Run down atfork prepare handlers. */
TAILQ_FOREACH_REVERSE(af, &_atfork_list, atfork_head, qe) {
if (af->prepare != NULL)
af->prepare();
}
if ((pid = _dofork(0)) == 0) {
/* Run down atfork child handlers. */
TAILQ_FOREACH(af, &_atfork_list, qe) {
if (af->child != NULL)
af->child();
}
_mutex_reinit(&_atfork_mutex);
} else {
/* Run down atfork parent handlers. */
TAILQ_FOREACH(af, &_atfork_list, qe) {
if (af->parent != NULL)
af->parent();
}
pthread_mutex_unlock(&_atfork_mutex);
}
/*
* Undefer and handle pending signals, yielding if necessary:
*/
_thread_kern_sig_undefer();
return(pid);
}
pid_t
_dofork(int vfork)
{
struct pthread *curthread = _get_curthread();
int i, flags;
pid_t ret;
pthread_t pthread;
/* Fork a new process and reset child's state */
if ((ret = (vfork ? _thread_sys_vfork() : _thread_sys_fork())) == 0) {
/* Close the pthread kernel pipe: */
_thread_sys_close(_thread_kern_pipe[0]);
_thread_sys_close(_thread_kern_pipe[1]);
/* Reset signals pending for the running thread: */
sigemptyset(&curthread->sigpend);
/*
* Create a pipe that is written to by the signal handler to
* prevent signals being missed in calls to
* _thread_sys_select:
*/
if (_thread_sys_pipe(_thread_kern_pipe) != 0) {
/* Cannot create pipe, so abort: */
PANIC("Cannot create pthread kernel pipe for forked process");
}
/* Get the flags for the read pipe: */
else if ((flags = _thread_sys_fcntl(_thread_kern_pipe[0], F_GETFL, NULL)) == -1) {
/* Abort this application: */
abort();
}
/* Make the read pipe non-blocking: */
else if (_thread_sys_fcntl(_thread_kern_pipe[0], F_SETFL, flags | O_NONBLOCK) == -1) {
/* Abort this application: */
abort();
}
/* Get the flags for the write pipe: */
else if ((flags = _thread_sys_fcntl(_thread_kern_pipe[1], F_GETFL, NULL)) == -1) {
/* Abort this application: */
abort();
}
/* Make the write pipe non-blocking: */
else if (_thread_sys_fcntl(_thread_kern_pipe[1], F_SETFL, flags | O_NONBLOCK) == -1) {
/* Abort this application: */
abort();
}
/* Reinitialize the GC mutex: */
else if (_mutex_reinit(&_gc_mutex) != 0) {
/* Abort this application: */
PANIC("Cannot initialize GC mutex for forked process");
}
/* Reinitialize the GC condition variable: */
else if (_cond_reinit(&_gc_cond) != 0) {
/* Abort this application: */
PANIC("Cannot initialize GC condvar for forked process");
}
/* Initialize the ready queue: */
else if (_pq_init(&_readyq) != 0) {
/* Abort this application: */
PANIC("Cannot initialize priority ready queue.");
} else {
/*
* Enter a loop to remove all threads other than
* the running thread from the thread list:
*/
while ((pthread = TAILQ_FIRST(&_thread_list)) != NULL) {
TAILQ_REMOVE(&_thread_list, pthread, tle);
/* Make sure this isn't the running thread: */
if (pthread != curthread) {
/* XXX should let gc do all this. */
if(pthread->stack != NULL)
_thread_stack_free(pthread->stack);
if (pthread->specific_data != NULL)
free(pthread->specific_data);
if (pthread->poll_data.fds != NULL)
free(pthread->poll_data.fds);
free(pthread);
}
}
/* Restore the running thread */
TAILQ_INSERT_HEAD(&_thread_list, curthread, tle);
/* Re-init the dead thread list: */
TAILQ_INIT(&_dead_list);
/* Re-init the waiting and work queues. */
TAILQ_INIT(&_waitingq);
TAILQ_INIT(&_workq);
/* Re-init the threads mutex queue: */
TAILQ_INIT(&curthread->mutexq);
/* No spinlocks yet: */
_spinblock_count = 0;
/* Don't queue signals yet: */
_queue_signals = 0;
/* Initialize signal handling: */
_thread_sig_init();
/* Initialize the scheduling switch hook routine: */
_sched_switch_hook = NULL;
/* Clear out any locks in the file descriptor table: */
for (i = 0; i < _thread_max_fdtsize; i++) {
if (_thread_fd_table[i] != NULL) {
/* Initialise the file locks: */
_SPINLOCK_INIT(&_thread_fd_table[i]->lock);
_thread_fd_table[i]->r_owner = NULL;
_thread_fd_table[i]->w_owner = NULL;
_thread_fd_table[i]->r_fname = NULL;
_thread_fd_table[i]->w_fname = NULL;
_thread_fd_table[i]->r_lineno = 0;
_thread_fd_table[i]->w_lineno = 0;
_thread_fd_table[i]->r_lockcount = 0;
_thread_fd_table[i]->w_lockcount = 0;
if (_thread_fd_table[i]->status_flags != NULL)
_SPINLOCK_INIT(&_thread_fd_table[i]->status_flags->lock);
/*
* If a fd was in the process of closing
* then finish closing it.
*/
if (_thread_fd_table[i]->state == FD_ENTRY_CLOSING) {
_thread_fd_entry_close(i);
_thread_sys_close(i);
}
/* Initialise the read/write queues: */
TAILQ_INIT(&_thread_fd_table[i]->r_queue);
TAILQ_INIT(&_thread_fd_table[i]->w_queue);
}
}
}
}
/* Return the process ID: */
return (ret);
}
#endif
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