thr_create.c revision 48749
1/* 2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by John Birrell. 16 * 4. Neither the name of the author nor the names of any co-contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $Id: uthread_create.c,v 1.16 1999/07/11 05:56:36 jasone Exp $ 33 */ 34#include <errno.h> 35#include <stdlib.h> 36#include <string.h> 37#include <fcntl.h> 38#include <unistd.h> 39#include <sys/time.h> 40#include <sys/types.h> 41#include <sys/mman.h> 42#ifdef _THREAD_SAFE 43#include <machine/reg.h> 44#include <pthread.h> 45#include "pthread_private.h" 46#include "libc_private.h" 47 48int 49pthread_create(pthread_t * thread, const pthread_attr_t * attr, 50 void *(*start_routine) (void *), void *arg) 51{ 52 int f_gc = 0; 53 int i; 54 int ret = 0; 55 int status; 56 pthread_t gc_thread; 57 pthread_t new_thread; 58 pthread_attr_t pattr; 59 void *stack; 60 61 /* 62 * Locking functions in libc are required when there are 63 * threads other than the initial thread. 64 */ 65 __isthreaded = 1; 66 67 /* Allocate memory for the thread structure: */ 68 if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) { 69 /* Insufficient memory to create a thread: */ 70 ret = EAGAIN; 71 } else { 72 /* Check if default thread attributes are required: */ 73 if (attr == NULL || *attr == NULL) { 74 /* Use the default thread attributes: */ 75 pattr = &pthread_attr_default; 76 } else { 77 pattr = *attr; 78 } 79 /* Check if a stack was specified in the thread attributes: */ 80 if ((stack = pattr->stackaddr_attr) != NULL) { 81 } 82 /* Allocate memory for a default-size stack: */ 83 else if (pattr->stacksize_attr == PTHREAD_STACK_DEFAULT) { 84 struct stack *spare_stack; 85 86 /* Allocate or re-use a default-size stack. */ 87 88 /* 89 * Use the garbage collector mutex for synchronization 90 * of the spare stack list. 91 */ 92 if (pthread_mutex_lock(&_gc_mutex) != 0) 93 PANIC("Cannot lock gc mutex"); 94 95 if ((spare_stack = SLIST_FIRST(&_stackq)) != NULL) { 96 /* Use the spare stack. */ 97 SLIST_REMOVE_HEAD(&_stackq, qe); 98 99 /* Unlock the garbage collector mutex. */ 100 if (pthread_mutex_unlock(&_gc_mutex) != 0) 101 PANIC("Cannot unlock gc mutex"); 102 103 stack = sizeof(struct stack) 104 + (void *) spare_stack 105 - PTHREAD_STACK_DEFAULT; 106 } else { 107 /* Unlock the garbage collector mutex. */ 108 if (pthread_mutex_unlock(&_gc_mutex) != 0) 109 PANIC("Cannot unlock gc mutex"); 110 111 /* Allocate a new stack. */ 112 stack = _next_stack + PTHREAD_STACK_GUARD; 113 /* 114 * Even if stack allocation fails, we don't want 115 * to try to use this location again, so 116 * unconditionally decrement _next_stack. Under 117 * normal operating conditions, the most likely 118 * reason for an mmap() error is a stack 119 * overflow of the adjacent thread stack. 120 */ 121 _next_stack -= (PTHREAD_STACK_DEFAULT 122 + PTHREAD_STACK_GUARD); 123 124 /* Red zone: */ 125 if (mmap(_next_stack, PTHREAD_STACK_GUARD, 0, 126 MAP_ANON, -1, 0) == MAP_FAILED) { 127 ret = EAGAIN; 128 free(new_thread); 129 } 130 /* Stack: */ 131 else if (mmap(stack, 132 PTHREAD_STACK_DEFAULT, 133 PROT_READ | PROT_WRITE, 134#ifdef __i386__ 135 MAP_STACK, 136#else 137 MAP_ANON, 138#endif 139 -1, 0) == MAP_FAILED) { 140 ret = EAGAIN; 141 munmap(_next_stack, 142 PTHREAD_STACK_GUARD); 143 free(new_thread); 144 } 145 } 146 } 147 /* 148 * The user wants a stack of a particular size. Lets hope they 149 * really know what they want, and simply malloc the stack. 150 */ 151 else if ((stack = (void *) malloc(pattr->stacksize_attr)) 152 == NULL) { 153 /* Insufficient memory to create a thread: */ 154 ret = EAGAIN; 155 free(new_thread); 156 } 157 158 /* Check for errors: */ 159 if (ret != 0) { 160 } else { 161 /* Initialise the thread structure: */ 162 memset(new_thread, 0, sizeof(struct pthread)); 163 new_thread->slice_usec = -1; 164 new_thread->sig_saved = 0; 165 new_thread->stack = stack; 166 new_thread->start_routine = start_routine; 167 new_thread->arg = arg; 168 169 /* 170 * Write a magic value to the thread structure 171 * to help identify valid ones: 172 */ 173 new_thread->magic = PTHREAD_MAGIC; 174 175 /* Initialise the thread for signals: */ 176 new_thread->sigmask = _thread_run->sigmask; 177 178 /* Initialise the jump buffer: */ 179 setjmp(new_thread->saved_jmp_buf); 180 181 /* 182 * Set up new stack frame so that it looks like it 183 * returned from a longjmp() to the beginning of 184 * _thread_start(). 185 */ 186#if defined(__FreeBSD__) 187#if defined(__alpha__) 188 new_thread->saved_jmp_buf[0]._jb[2] = (long) _thread_start; 189 new_thread->saved_jmp_buf[0]._jb[4 + R_RA] = 0; 190 new_thread->saved_jmp_buf[0]._jb[4 + R_T12] = (long) _thread_start; 191#else 192 new_thread->saved_jmp_buf[0]._jb[0] = (long) _thread_start; 193#endif 194#elif defined(__NetBSD__) 195#if defined(__alpha__) 196 new_thread->saved_jmp_buf[2] = (long) _thread_start; 197 new_thread->saved_jmp_buf[4 + R_RA] = 0; 198 new_thread->saved_jmp_buf[4 + R_T12] = (long) _thread_start; 199#else 200 new_thread->saved_jmp_buf[0] = (long) _thread_start; 201#endif 202#else 203#error "Don't recognize this operating system!" 204#endif 205 206 /* The stack starts high and builds down: */ 207#if defined(__FreeBSD__) 208#if defined(__alpha__) 209 new_thread->saved_jmp_buf[0]._jb[4 + R_SP] = (long) new_thread->stack + pattr->stacksize_attr - sizeof(double); 210#else 211 new_thread->saved_jmp_buf[0]._jb[2] = (int) (new_thread->stack + pattr->stacksize_attr - sizeof(double)); 212#endif 213#elif defined(__NetBSD__) 214#if defined(__alpha__) 215 new_thread->saved_jmp_buf[4 + R_SP] = (long) new_thread->stack + pattr->stacksize_attr - sizeof(double); 216#else 217 new_thread->saved_jmp_buf[2] = (long) new_thread->stack + pattr->stacksize_attr - sizeof(double); 218#endif 219#else 220#error "Don't recognize this operating system!" 221#endif 222 223 /* Copy the thread attributes: */ 224 memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr)); 225 226 /* 227 * Check if this thread is to inherit the scheduling 228 * attributes from its parent: 229 */ 230 if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) { 231 /* Copy the scheduling attributes: */ 232 new_thread->base_priority 233 = _thread_run->base_priority; 234 new_thread->attr.prio 235 = _thread_run->base_priority; 236 new_thread->attr.sched_policy 237 = _thread_run->attr.sched_policy; 238 } else { 239 /* 240 * Use just the thread priority, leaving the 241 * other scheduling attributes as their 242 * default values: 243 */ 244 new_thread->base_priority 245 = new_thread->attr.prio; 246 } 247 new_thread->active_priority = new_thread->base_priority; 248 new_thread->inherited_priority = 0; 249 250 /* Initialise the join queue for the new thread: */ 251 TAILQ_INIT(&(new_thread->join_queue)); 252 253 /* Initialize the mutex queue: */ 254 TAILQ_INIT(&new_thread->mutexq); 255 256 /* Initialise hooks in the thread structure: */ 257 new_thread->specific_data = NULL; 258 new_thread->cleanup = NULL; 259 new_thread->flags = 0; 260 new_thread->poll_data.nfds = 0; 261 new_thread->poll_data.fds = NULL; 262 263 /* 264 * Defer signals to protect the scheduling queues 265 * from access by the signal handler: 266 */ 267 _thread_kern_sig_defer(); 268 269 /* 270 * Check if the garbage collector thread 271 * needs to be started. 272 */ 273 f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial); 274 275 /* Add the thread to the linked list of all threads: */ 276 TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle); 277 278 if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) { 279 new_thread->state = PS_SUSPENDED; 280 PTHREAD_WAITQ_INSERT(new_thread); 281 } else { 282 new_thread->state = PS_RUNNING; 283 PTHREAD_PRIOQ_INSERT_TAIL(new_thread); 284 } 285 286 /* 287 * Undefer and handle pending signals, yielding 288 * if necessary. 289 */ 290 _thread_kern_sig_undefer(); 291 292 /* Return a pointer to the thread structure: */ 293 (*thread) = new_thread; 294 295 /* Schedule the new user thread: */ 296 _thread_kern_sched(NULL); 297 298 /* 299 * Start a garbage collector thread 300 * if necessary. 301 */ 302 if (f_gc && pthread_create(&gc_thread,NULL, 303 _thread_gc,NULL) != 0) 304 PANIC("Can't create gc thread"); 305 } 306 } 307 308 /* Return the status: */ 309 return (ret); 310} 311 312void 313_thread_start(void) 314{ 315 /* We just left the scheduler via longjmp: */ 316 _thread_kern_in_sched = 0; 317 318 /* Run the current thread's start routine with argument: */ 319 pthread_exit(_thread_run->start_routine(_thread_run->arg)); 320 321 /* This point should never be reached. */ 322 PANIC("Thread has resumed after exit"); 323} 324#endif 325