/* $OpenBSD: uthread_create.c,v 1.25 2010/07/13 04:24:46 guenther 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_create.c,v 1.19 1999/08/28 00:03:28 peter Exp $ */ #include #include #include #include #include #include #include #include #include #ifdef _THREAD_SAFE #include #include #include "pthread_private.h" /* Symbols that help gdb find the information it needs. */ int _thread_next_offset = offsetof(struct pthread, tle.tqe_next); int _thread_state_offset = offsetof(struct pthread, state); int _thread_ctx_offset = offsetof(struct pthread, _machdep); int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine) (void *), void *arg) { struct pthread *curthread = _get_curthread(); struct itimerval itimer; int f_gc = 0; int ret = 0; pthread_t gc_thread; pthread_t new_thread; pthread_attr_t pattr; struct stack *stack; if (thread == NULL) return(EINVAL); /* * Locking functions in libc are required when there are * threads other than the initial thread. */ __isthreaded = 1; /* Allocate memory for the thread structure: */ if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) { /* Insufficient memory to create a thread: */ ret = EAGAIN; } else { /* Check if default thread attributes are required: */ if (attr == NULL || *attr == NULL) { /* Use the default thread attributes: */ pattr = &pthread_attr_default; } else { pattr = *attr; } /* Allocate a stack: */ stack = _thread_stack_alloc(pattr->stackaddr_attr, pattr->stacksize_attr, pattr->guardsize_attr); if (stack == NULL) { ret = EAGAIN; free(new_thread); } /* Check for errors: */ if (ret != 0) { } else { /* Initialise the thread structure: */ memset(new_thread, 0, sizeof(struct pthread)); _SPINLOCK_INIT(&new_thread->lock); new_thread->slice_usec = -1; new_thread->sig_saved = 0; new_thread->stack = stack; new_thread->start_routine = start_routine; new_thread->arg = arg; new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | PTHREAD_CANCEL_DEFERRED; /* * Write a magic value to the thread structure * to help identify valid ones: */ new_thread->magic = PTHREAD_MAGIC; /* Initialise the thread for signals: */ new_thread->sigmask = curthread->sigmask; /* * Set up new stack frame so that it 'returns' to * the beginning of _thread_start() after it is * switched to: */ _thread_machdep_init(&new_thread->_machdep, stack->base, stack->size, _thread_start); /* Copy the thread attributes: */ memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr)); /* * Check if this thread is to inherit the scheduling * attributes from its parent: */ if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) { /* Copy the scheduling attributes: */ new_thread->base_priority = curthread->base_priority & ~PTHREAD_SIGNAL_PRIORITY; new_thread->attr.prio = curthread->base_priority & ~PTHREAD_SIGNAL_PRIORITY; new_thread->attr.sched_policy = curthread->attr.sched_policy; } else { /* * Use just the thread priority, leaving the * other scheduling attributes as their * default values: */ new_thread->base_priority = new_thread->attr.prio; } new_thread->active_priority = new_thread->base_priority; new_thread->inherited_priority = 0; /* Initialize joiner to NULL (no joiner): */ new_thread->joiner = NULL; /* Initialize the mutex queue: */ TAILQ_INIT(&new_thread->mutexq); /* Initialise hooks in the thread structure: */ new_thread->specific_data = NULL; new_thread->cleanup = NULL; new_thread->flags = 0; new_thread->poll_data.nfds = 0; new_thread->poll_data.fds = NULL; new_thread->continuation = NULL; /* * Defer signals to protect the scheduling queues * from access by the signal handler: */ _thread_kern_sig_defer(); /* * Check if the garbage collector thread * needs to be started. */ f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial && start_routine != _thread_gc); /* Add the thread to the linked list of all threads: */ TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle); if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) new_thread->state = PS_SUSPENDED; else { new_thread->state = PS_RUNNING; PTHREAD_PRIOQ_INSERT_TAIL(new_thread); } /* * Undefer and handle pending signals, yielding * if necessary. */ _thread_kern_sig_undefer(); /* Return a pointer to the thread structure: */ if (thread != NULL) (*thread) = new_thread; if (f_gc != 0) { /* Install the scheduling timer: */ itimer.it_interval.tv_sec = 0; itimer.it_interval.tv_usec = _clock_res_usec; itimer.it_value = itimer.it_interval; if (setitimer(_ITIMER_SCHED_TIMER, &itimer, NULL) != 0) PANIC("Cannot set interval timer"); } /* Schedule the new user thread: */ _thread_kern_sched(NULL); /* * Start a garbage collector thread * if necessary. */ if (f_gc && pthread_create(&gc_thread,NULL, _thread_gc,NULL) != 0) PANIC("Can't create gc thread"); } } /* Return the status: */ return (ret); } void _thread_start(void) { struct pthread *curthread = _get_curthread(); /* We just left the scheduler via longjmp: */ _thread_kern_in_sched = 0; /* Run the current thread's start routine with argument: */ pthread_exit(curthread->start_routine(curthread->arg)); /* This point should never be reached. */ PANIC("Thread has resumed after exit"); } #endif