thr_create.c revision 58094
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 AUTHOR 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 * $FreeBSD: head/lib/libkse/thread/thr_create.c 58094 2000-03-15 13:59:27Z deischen $ 33 */ 34#include <errno.h> 35#include <stdlib.h> 36#include <string.h> 37#include <fcntl.h> 38#include <unistd.h> 39#include <stddef.h> 40#include <sys/time.h> 41#include <sys/param.h> 42#include <sys/mman.h> 43#ifdef _THREAD_SAFE 44#include <machine/reg.h> 45#include <pthread.h> 46#include "pthread_private.h" 47#include "libc_private.h" 48 49static u_int64_t next_uniqueid = 1; 50 51#define OFF(f) offsetof(struct pthread, f) 52int _thread_next_offset = OFF(tle.tqe_next); 53int _thread_uniqueid_offset = OFF(uniqueid); 54int _thread_state_offset = OFF(state); 55int _thread_name_offset = OFF(name); 56int _thread_sig_saved_offset = OFF(sig_saved); 57int _thread_saved_sigcontext_offset = OFF(saved_sigcontext); 58int _thread_saved_jmp_buf_offset = OFF(saved_jmp_buf); 59#undef OFF 60 61int _thread_PS_RUNNING_value = PS_RUNNING; 62int _thread_PS_DEAD_value = PS_DEAD; 63 64int 65pthread_create(pthread_t * thread, const pthread_attr_t * attr, 66 void *(*start_routine) (void *), void *arg) 67{ 68 int f_gc = 0; 69 int ret = 0; 70 pthread_t gc_thread; 71 pthread_t new_thread; 72 pthread_attr_t pattr; 73 void *stack; 74 75 /* 76 * Locking functions in libc are required when there are 77 * threads other than the initial thread. 78 */ 79 __isthreaded = 1; 80 81 /* Allocate memory for the thread structure: */ 82 if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) { 83 /* Insufficient memory to create a thread: */ 84 ret = EAGAIN; 85 } else { 86 /* Check if default thread attributes are required: */ 87 if (attr == NULL || *attr == NULL) { 88 /* Use the default thread attributes: */ 89 pattr = &pthread_attr_default; 90 } else { 91 pattr = *attr; 92 } 93 /* Check if a stack was specified in the thread attributes: */ 94 if ((stack = pattr->stackaddr_attr) != NULL) { 95 } 96 /* Allocate memory for a default-size stack: */ 97 else if (pattr->stacksize_attr == PTHREAD_STACK_DEFAULT) { 98 struct stack *spare_stack; 99 100 /* Allocate or re-use a default-size stack. */ 101 102 /* 103 * Use the garbage collector mutex for synchronization 104 * of the spare stack list. 105 */ 106 if (pthread_mutex_lock(&_gc_mutex) != 0) 107 PANIC("Cannot lock gc mutex"); 108 109 if ((spare_stack = SLIST_FIRST(&_stackq)) != NULL) { 110 /* Use the spare stack. */ 111 SLIST_REMOVE_HEAD(&_stackq, qe); 112 113 /* Unlock the garbage collector mutex. */ 114 if (pthread_mutex_unlock(&_gc_mutex) != 0) 115 PANIC("Cannot unlock gc mutex"); 116 117 stack = sizeof(struct stack) 118 + (void *) spare_stack 119 - PTHREAD_STACK_DEFAULT; 120 } else { 121 /* Allocate a new stack. */ 122 stack = _next_stack + PTHREAD_STACK_GUARD; 123 124 /* 125 * Even if stack allocation fails, we don't want 126 * to try to use this location again, so 127 * unconditionally decrement _next_stack. Under 128 * normal operating conditions, the most likely 129 * reason for an mmap() error is a stack 130 * overflow of the adjacent thread stack. 131 */ 132 _next_stack -= (PTHREAD_STACK_DEFAULT 133 + PTHREAD_STACK_GUARD); 134 135 /* Unlock the garbage collector mutex. */ 136 if (pthread_mutex_unlock(&_gc_mutex) != 0) 137 PANIC("Cannot unlock gc mutex"); 138 139 /* Stack: */ 140 if (mmap(stack, PTHREAD_STACK_DEFAULT, 141 PROT_READ | PROT_WRITE, MAP_STACK, 142 -1, 0) == MAP_FAILED) { 143 ret = EAGAIN; 144 free(new_thread); 145 } 146 } 147 } 148 /* 149 * The user wants a stack of a particular size. Lets hope they 150 * really know what they want, and simply malloc the stack. 151 */ 152 else if ((stack = (void *) malloc(pattr->stacksize_attr)) 153 == NULL) { 154 /* Insufficient memory to create a thread: */ 155 ret = EAGAIN; 156 free(new_thread); 157 } 158 159 /* Check for errors: */ 160 if (ret != 0) { 161 } else { 162 /* Initialise the thread structure: */ 163 memset(new_thread, 0, sizeof(struct pthread)); 164 new_thread->slice_usec = -1; 165 new_thread->sig_saved = 0; 166 new_thread->stack = stack; 167 new_thread->start_routine = start_routine; 168 new_thread->arg = arg; 169 170 new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | 171 PTHREAD_CANCEL_DEFERRED; 172 173 /* 174 * Write a magic value to the thread structure 175 * to help identify valid ones: 176 */ 177 new_thread->magic = PTHREAD_MAGIC; 178 179 /* Initialise the thread for signals: */ 180 new_thread->sigmask = _thread_run->sigmask; 181 182 /* Initialise the jump buffer: */ 183 setjmp(new_thread->saved_jmp_buf); 184 185 /* 186 * Set up new stack frame so that it looks like it 187 * returned from a longjmp() to the beginning of 188 * _thread_start(). 189 */ 190#if defined(__FreeBSD__) 191#if defined(__alpha__) 192 new_thread->saved_jmp_buf[0]._jb[2] = 193 (long)_thread_start; 194 new_thread->saved_jmp_buf[0]._jb[4 + R_RA] = 195 0; 196 new_thread->saved_jmp_buf[0]._jb[4 + R_T12] = 197 (long)_thread_start; 198#else 199 new_thread->saved_jmp_buf[0]._jb[0] = 200 (long)_thread_start; 201#endif 202#elif defined(__NetBSD__) 203#if defined(__alpha__) 204 new_thread->saved_jmp_buf[2] = (long)_thread_start; 205 new_thread->saved_jmp_buf[4 + R_RA] = 0; 206 new_thread->saved_jmp_buf[4 + R_T12] = 207 (long)_thread_start; 208#else 209 new_thread->saved_jmp_buf[0] = (long)_thread_start; 210#endif 211#else 212#error "Don't recognize this operating system!" 213#endif 214 215 /* The stack starts high and builds down: */ 216#if defined(__FreeBSD__) 217#if defined(__alpha__) 218 new_thread->saved_jmp_buf[0]._jb[4 + R_SP] = 219 (long)new_thread->stack + pattr->stacksize_attr 220 - sizeof(double); 221#else 222 new_thread->saved_jmp_buf[0]._jb[2] = 223 (int)(new_thread->stack + pattr->stacksize_attr - 224 sizeof(double)); 225#endif 226#elif defined(__NetBSD__) 227#if defined(__alpha__) 228 new_thread->saved_jmp_buf[4 + R_SP] = 229 (long)new_thread->stack + pattr->stacksize_attr - 230 sizeof(double); 231#else 232 new_thread->saved_jmp_buf[2] = (long)new_thread->stack 233 + pattr->stacksize_attr - sizeof(double); 234#endif 235#else 236#error "Don't recognize this operating system!" 237#endif 238 239 /* Copy the thread attributes: */ 240 memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr)); 241 242 /* 243 * Check if this thread is to inherit the scheduling 244 * attributes from its parent: 245 */ 246 if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) { 247 /* Copy the scheduling attributes: */ 248 new_thread->base_priority 249 = _thread_run->base_priority; 250 new_thread->attr.prio 251 = _thread_run->base_priority; 252 new_thread->attr.sched_policy 253 = _thread_run->attr.sched_policy; 254 } else { 255 /* 256 * Use just the thread priority, leaving the 257 * other scheduling attributes as their 258 * default values: 259 */ 260 new_thread->base_priority 261 = new_thread->attr.prio; 262 } 263 new_thread->active_priority = new_thread->base_priority; 264 new_thread->inherited_priority = 0; 265 266 /* Initialise the join queue for the new thread: */ 267 TAILQ_INIT(&(new_thread->join_queue)); 268 269 /* Initialize the mutex queue: */ 270 TAILQ_INIT(&new_thread->mutexq); 271 272 /* Initialise hooks in the thread structure: */ 273 new_thread->specific_data = NULL; 274 new_thread->cleanup = NULL; 275 new_thread->flags = 0; 276 new_thread->poll_data.nfds = 0; 277 new_thread->poll_data.fds = NULL; 278 new_thread->jmpflags = 0; 279 new_thread->continuation = NULL; 280 281 /* 282 * Defer signals to protect the scheduling queues 283 * from access by the signal handler: 284 */ 285 _thread_kern_sig_defer(); 286 287 /* 288 * Initialise the unique id which GDB uses to 289 * track threads. 290 */ 291 new_thread->uniqueid = next_uniqueid++; 292 293 /* 294 * Check if the garbage collector thread 295 * needs to be started. 296 */ 297 f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial); 298 299 /* Add the thread to the linked list of all threads: */ 300 TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle); 301 302 if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) 303 new_thread->state = PS_SUSPENDED; 304 else { 305 new_thread->state = PS_RUNNING; 306 PTHREAD_PRIOQ_INSERT_TAIL(new_thread); 307 } 308 309 /* 310 * Undefer and handle pending signals, yielding 311 * if necessary. 312 */ 313 _thread_kern_sig_undefer(); 314 315 /* Return a pointer to the thread structure: */ 316 (*thread) = new_thread; 317 318 /* Schedule the new user thread: */ 319 _thread_kern_sched(NULL); 320 321 /* 322 * Start a garbage collector thread 323 * if necessary. 324 */ 325 if (f_gc && pthread_create(&gc_thread,NULL, 326 _thread_gc,NULL) != 0) 327 PANIC("Can't create gc thread"); 328 } 329 } 330 331 /* Return the status: */ 332 return (ret); 333} 334 335void 336_thread_start(void) 337{ 338 /* We just left the scheduler via longjmp: */ 339 _thread_kern_in_sched = 0; 340 341 /* Run the current thread's start routine with argument: */ 342 pthread_exit(_thread_run->start_routine(_thread_run->arg)); 343 344 /* This point should never be reached. */ 345 PANIC("Thread has resumed after exit"); 346} 347#endif 348