/* $OpenBSD: uthread_fork.c,v 1.11 2003/08/06 21:08:05 millert Exp $ */ /* * Copyright (c) 1995-1998 John Birrell * 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 #include #include #include #include #ifdef _THREAD_SAFE #include #include "pthread_private.h" pid_t fork(void) { struct pthread *curthread = _get_curthread(); int i, flags; pid_t ret; pthread_t pthread; /* * Defer signals to protect the scheduling queues from access * by the signal handler: */ _thread_kern_sig_defer(); /* Fork a new process: */ if ((ret = _thread_sys_fork()) != 0) { /* Parent process or error. Nothing to do here. */ } else { /* 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_dtablesize; 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; /* 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); } #endif