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/*
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <pthread.h>
#include "pthread_private.h"
static void free_thread_resources(struct pthread *thread);
__weak_reference(_fork, fork);
pid_t
_fork(void)
{
struct pthread *curthread = _get_curthread();
int i, flags, use_deadlist = 0;
pid_t ret;
pthread_t pthread;
pthread_t pthread_save;
/*
* Defer signals to protect the scheduling queues from access
* by the signal handler:
*/
_thread_kern_sig_defer();
/* Fork a new process: */
if ((ret = __sys_fork()) != 0) {
/* Parent process or error. Nothing to do here. */
} else {
/* Close the pthread kernel pipe: */
__sys_close(_thread_kern_pipe[0]);
__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
* __sys_select:
*/
if (__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 = __sys_fcntl(_thread_kern_pipe[0], F_GETFL, NULL)) == -1) {
/* Abort this application: */
abort();
}
/* Make the read pipe non-blocking: */
else if (__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 = __sys_fcntl(_thread_kern_pipe[1], F_GETFL, NULL)) == -1) {
/* Abort this application: */
abort();
}
/* Make the write pipe non-blocking: */
else if (__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:
*/
if ((pthread = TAILQ_FIRST(&_thread_list)) == NULL) {
pthread = TAILQ_FIRST(&_dead_list);
use_deadlist = 1;
}
while (pthread != NULL) {
/* Save the thread to be freed: */
pthread_save = pthread;
/*
* Advance to the next thread before
* destroying the current thread:
*/
if (use_deadlist != 0)
pthread = TAILQ_NEXT(pthread, dle);
else
pthread = TAILQ_NEXT(pthread, tle);
/* Make sure this isn't the running thread: */
if (pthread_save != curthread) {
/*
* Remove this thread from the
* appropriate list:
*/
if (use_deadlist != 0)
TAILQ_REMOVE(&_thread_list,
pthread_save, dle);
else
TAILQ_REMOVE(&_thread_list,
pthread_save, tle);
free_thread_resources(pthread_save);
}
/*
* Switch to the deadlist when the active
* thread list has been consumed. This can't
* be at the top of the loop because it is
* used to determine to which list the thread
* belongs (when it is removed from the list).
*/
if (pthread == NULL) {
pthread = TAILQ_FIRST(&_dead_list);
use_deadlist = 1;
}
}
/* Treat the current thread as the initial thread: */
_thread_initial = curthread;
/* 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 the scheduling switch hook routine: */
_sched_switch_hook = NULL;
/* Clear out any locks in the file descriptor table: */
for (i = 0; i < _thread_dtablesize; i++) {
if (_thread_fd_table[i] != NULL) {
/* Initialise the file locks: */
memset(&_thread_fd_table[i]->lock, 0,
sizeof(_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;;
/* Initialise the read/write queues: */
TAILQ_INIT(&_thread_fd_table[i]->r_queue);
TAILQ_INIT(&_thread_fd_table[i]->w_queue);
}
}
}
}
/*
* Undefer and handle pending signals, yielding if necessary:
*/
_thread_kern_sig_undefer();
/* Return the process ID: */
return (ret);
}
static void
free_thread_resources(struct pthread *thread)
{
/* Check to see if the threads library allocated the stack. */
if ((thread->attr.stackaddr_attr == NULL) && (thread->stack != NULL)) {
/*
* Since this is being called from fork, we are currently single
* threaded so there is no need to protect the call to
* _thread_stack_free() with _gc_mutex.
*/
_thread_stack_free(thread->stack, thread->attr.stacksize_attr,
thread->attr.guardsize_attr);
}
if (thread->specific_data != NULL)
free(thread->specific_data);
if (thread->poll_data.fds != NULL)
free(thread->poll_data.fds);
free(thread);
}
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