/* * Copyright (c) 1995 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 REGENTS 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. * */ #include #include #include #include #include #include #ifdef _THREAD_SAFE #include #include #include "pthread_private.h" int _thread_create(pthread_t * thread, const pthread_attr_t * attr, void *(*start_routine) (void *), void *arg, pthread_t parent) { int i; int ret = 0; int status; pthread_t new_thread; pthread_attr_t pattr; void *stack; /* Block signals: */ _thread_kern_sig_block(&status); /* 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; } /* Check if a stack was specified in the thread attributes: */ if ((stack = pattr->stackaddr_attr) != NULL) { } /* Allocate memory for the stack: */ else if ((stack = (void *) malloc(pattr->stacksize_attr)) == NULL) { /* Insufficient memory to create a thread: */ ret = EAGAIN; free(new_thread); } /* Check for errors: */ if (ret != 0) { } else { /* Initialise the thread structure: */ memset(new_thread, 0, sizeof(struct pthread)); new_thread->slice_usec = -1; new_thread->sig_saved = 0; new_thread->stack = stack; new_thread->start_routine = start_routine; new_thread->arg = arg; if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) { new_thread->state = PS_SUSPENDED; } else { new_thread->state = PS_RUNNING; } /* Initialise the thread for signals: */ new_thread->sigmask = _thread_run->sigmask; /* * Enter a loop to initialise the signal handler * array: */ for (i = 1; i < NSIG; i++) { /* Default the signal handler: */ sigfillset(&new_thread->act[i - 1].sa_mask); new_thread->act[i - 1].sa_handler = _thread_run->act[i - 1].sa_handler; new_thread->act[i - 1].sa_flags = _thread_run->act[i - 1].sa_flags; } /* Initialise the jump buffer: */ _thread_sys_setjmp(new_thread->saved_jmp_buf); /* * Set up new stack frame so that it looks like it * returned from a longjmp() to the beginning of * _thread_start(). Check if this is a user thread: */ if (parent == NULL) { /* Use the user start function: */ #if defined(__FreeBSD__) new_thread->saved_jmp_buf[0]._jb[0] = (long) _thread_start; #elif defined(__NetBSD__) #if defined(__alpha) new_thread->saved_jmp_buf[2] = (long) _thread_start; new_thread->saved_jmp_buf[4 + R_RA] = 0; new_thread->saved_jmp_buf[4 + R_T12] = (long) _thread_start; #else new_thread->saved_jmp_buf[0] = (long) _thread_start; #endif #else #error "Don't recognize this operating system!" #endif } else { /* * Use the (funny) signal handler start * function: */ #if defined(__FreeBSD__) new_thread->saved_jmp_buf[0]._jb[0] = (int) _thread_start_sig_handler; #elif defined(__NetBSD__) #if defined(__alpha) new_thread->saved_jmp_buf[2] = (long) _thread_start_sig_handler; new_thread->saved_jmp_buf[4 + R_RA] = 0; new_thread->saved_jmp_buf[4 + R_T12] = (long) _thread_start_sig_handler; #else new_thread->saved_jmp_buf[0] = (long) _thread_start_sig_handler; #endif #else #error "Don't recognize this operating system!" #endif } /* The stack starts high and builds down: */ #if defined(__FreeBSD__) new_thread->saved_jmp_buf[0]._jb[2] = (int) (new_thread->stack + pattr->stacksize_attr - sizeof(double)); #elif defined(__NetBSD__) #if defined(__alpha) new_thread->saved_jmp_buf[4 + R_SP] = (long) new_thread->stack + pattr->stacksize_attr - sizeof(double); #else new_thread->saved_jmp_buf[2] = (long) new_thread->stack + pattr->stacksize_attr - sizeof(double); #endif #else #error "Don't recognize this operating system!" #endif /* 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->pthread_priority = _thread_run->pthread_priority; new_thread->attr.prio = _thread_run->pthread_priority; new_thread->attr.schedparam_policy = _thread_run->attr.schedparam_policy; } else { /* * Use just the thread priority, leaving the * other scheduling attributes as their * default values: */ new_thread->pthread_priority = new_thread->attr.prio; } /* Initialise the join queue for the new thread: */ _thread_queue_init(&(new_thread->join_queue)); /* Initialise hooks in the thread structure: */ new_thread->specific_data = NULL; new_thread->cleanup = NULL; new_thread->queue = NULL; new_thread->qnxt = NULL; new_thread->parent_thread = parent; new_thread->flags = 0; /* Add the thread to the linked list of all threads: */ new_thread->nxt = _thread_link_list; _thread_link_list = new_thread; /* Return a pointer to the thread structure: */ (*thread) = new_thread; /* Check if a parent thread was specified: */ if (parent != NULL) { /* * A parent thread was specified, so this is * a signal handler thread which must now * wait for the signal handler to complete: */ parent->state = PS_SIGTHREAD; } else { /* Schedule the new user thread: */ _thread_kern_sched(NULL); } } } /* Unblock signals: */ _thread_kern_sig_unblock(status); /* Return the status: */ return (ret); } int pthread_create(pthread_t * thread, const pthread_attr_t * attr, void *(*start_routine) (void *), void *arg) { int ret = 0; /* * Call the low level thread creation function which allows a parent * thread to be specified: */ ret = _thread_create(thread, attr, start_routine, arg, NULL); /* Return the status: */ return (ret); } void _thread_start(void) { /* Run the current thread's start routine with argument: */ pthread_exit(_thread_run->start_routine(_thread_run->arg)); /* This point should never be reached. */ PANIC("Thread has resumed after exit"); } void _thread_start_sig_handler(void) { int sig; long arg; void (*sig_routine) (int); /* * Cast the argument from 'void *' to a variable that is NO SMALLER * than a pointer (otherwise gcc under NetBSD/Alpha will complain): */ arg = (long) _thread_run->arg; /* Cast the argument as a signal number: */ sig = (int) arg; /* Cast a pointer to the signal handler function: */ sig_routine = (void (*) (int)) _thread_run->start_routine; /* Call the signal handler function: */ (*sig_routine) (sig); /* Exit the signal handler thread: */ pthread_exit(&arg); /* This point should never be reached. */ PANIC("Signal handler thread has resumed after exit"); } #endif