lib/libkse/thread/thr_create.c

   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  * $FreeBSD$
  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
  48 int
  49 pthread_create(pthread_t * thread, const pthread_attr_t * attr,
  50                void *(*start_routine) (void *), void *arg)
  51 {
  52         int             f_gc = 0;
  53         int             ret = 0;
  54         pthread_t       gc_thread;
  55         pthread_t       new_thread;
  56         pthread_attr_t  pattr;
  57         void           *stack;
  58
  59         /*
  60          * Locking functions in libc are required when there are
  61          * threads other than the initial thread.
  62          */
  63         __isthreaded = 1;
  64
  65         /* Allocate memory for the thread structure: */
  66         if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) {
  67                 /* Insufficient memory to create a thread: */
  68                 ret = EAGAIN;
  69         } else {
  70                 /* Check if default thread attributes are required: */
  71                 if (attr == NULL || *attr == NULL) {
  72                         /* Use the default thread attributes: */
  73                         pattr = &pthread_attr_default;
  74                 } else {
  75                         pattr = *attr;
  76                 }
  77                 /* Check if a stack was specified in the thread attributes: */
  78                 if ((stack = pattr->stackaddr_attr) != NULL) {
  79                 }
  80                 /* Allocate memory for a default-size stack: */
  81                 else if (pattr->stacksize_attr == PTHREAD_STACK_DEFAULT) {
  82                         struct stack    *spare_stack;
  83
  84                         /* Allocate or re-use a default-size stack. */
  85
  86                         /*
  87                          * Use the garbage collector mutex for synchronization
  88                          * of the spare stack list.
  89                          */
  90                         if (pthread_mutex_lock(&_gc_mutex) != 0)
  91                                 PANIC("Cannot lock gc mutex");
  92
  93                         if ((spare_stack = SLIST_FIRST(&_stackq)) != NULL) {
  94                                 /* Use the spare stack. */
  95                                 SLIST_REMOVE_HEAD(&_stackq, qe);
  96
  97                                 /* Unlock the garbage collector mutex. */
  98                                 if (pthread_mutex_unlock(&_gc_mutex) != 0)
  99                                         PANIC("Cannot unlock gc mutex");
 100
 101                                 stack = sizeof(struct stack)
 102                                     + (void *) spare_stack
 103                                     - PTHREAD_STACK_DEFAULT;
 104                         } else {
 105                                 /* Unlock the garbage collector mutex. */
 106                                 if (pthread_mutex_unlock(&_gc_mutex) != 0)
 107                                         PANIC("Cannot unlock gc mutex");
 108
 109                                 /* Allocate a new stack. */
 110                                 stack = _next_stack + PTHREAD_STACK_GUARD;
 111                                 /*
 112                                  * Even if stack allocation fails, we don't want
 113                                  * to try to use this location again, so
 114                                  * unconditionally decrement _next_stack.  Under
 115                                  * normal operating conditions, the most likely
 116                                  * reason for an mmap() error is a stack
 117                                  * overflow of the adjacent thread stack.
 118                                  */
 119                                 _next_stack -= (PTHREAD_STACK_DEFAULT
 120                                                 + PTHREAD_STACK_GUARD);
 121
 122                                 /* Red zone: */
 123                                 if (mmap(_next_stack, PTHREAD_STACK_GUARD, 0,
 124                                          MAP_ANON, -1, 0) == MAP_FAILED) {
 125                                         ret = EAGAIN;
 126                                         free(new_thread);
 127                                 }
 128                                 /* Stack: */
 129                                 else if (mmap(stack,
 130                                               PTHREAD_STACK_DEFAULT,
 131                                               PROT_READ | PROT_WRITE,
 132 #ifdef __i386__
 133                                               MAP_STACK,
 134 #else
 135                                               MAP_ANON,
 136 #endif
 137                                               -1, 0) == MAP_FAILED) {
 138                                         ret = EAGAIN;
 139                                         munmap(_next_stack,
 140                                                PTHREAD_STACK_GUARD);
 141                                         free(new_thread);
 142                                 }
 143                         }
 144                 }
 145                 /*
 146                  * The user wants a stack of a particular size.  Lets hope they
 147                  * really know what they want, and simply malloc the stack.
 148                  */
 149                 else if ((stack = (void *) malloc(pattr->stacksize_attr))
 150                          == NULL) {
 151                         /* Insufficient memory to create a thread: */
 152                         ret = EAGAIN;
 153                         free(new_thread);
 154                 }
 155
 156                 /* Check for errors: */
 157                 if (ret != 0) {
 158                 } else {
 159                         /* Initialise the thread structure: */
 160                         memset(new_thread, 0, sizeof(struct pthread));
 161                         new_thread->slice_usec = -1;
 162                         new_thread->sig_saved = 0;
 163                         new_thread->stack = stack;
 164                         new_thread->start_routine = start_routine;
 165                         new_thread->arg = arg;
 166
 167                         new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
 168                             PTHREAD_CANCEL_DEFERRED;
 169
 170                         /*
 171                          * Write a magic value to the thread structure
 172                          * to help identify valid ones:
 173                          */
 174                         new_thread->magic = PTHREAD_MAGIC;
 175
 176                         /* Initialise the thread for signals: */
 177                         new_thread->sigmask = _thread_run->sigmask;
 178
 179                         /* Initialise the jump buffer: */
 180                         setjmp(new_thread->saved_jmp_buf);
 181
 182                         /*
 183                          * Set up new stack frame so that it looks like it
 184                          * returned from a longjmp() to the beginning of
 185                          * _thread_start().
 186                          */
 187 #if     defined(__FreeBSD__)
 188 #if     defined(__alpha__)
 189                         new_thread->saved_jmp_buf[0]._jb[2] = (long) _thread_start;
 190                         new_thread->saved_jmp_buf[0]._jb[4 + R_RA] = 0;
 191                         new_thread->saved_jmp_buf[0]._jb[4 + R_T12] = (long) _thread_start;
 192 #else
 193                         new_thread->saved_jmp_buf[0]._jb[0] = (long) _thread_start;
 194 #endif
 195 #elif   defined(__NetBSD__)
 196 #if     defined(__alpha__)
 197                         new_thread->saved_jmp_buf[2] = (long) _thread_start;
 198                         new_thread->saved_jmp_buf[4 + R_RA] = 0;
 199                         new_thread->saved_jmp_buf[4 + R_T12] = (long) _thread_start;
 200 #else
 201                         new_thread->saved_jmp_buf[0] = (long) _thread_start;
 202 #endif
 203 #else
 204 #error  "Don't recognize this operating system!"
 205 #endif
 206
 207                         /* The stack starts high and builds down: */
 208 #if     defined(__FreeBSD__)
 209 #if     defined(__alpha__)
 210                         new_thread->saved_jmp_buf[0]._jb[4 + R_SP] = (long) new_thread->stack + pattr->stacksize_attr - sizeof(double);
 211 #else
 212                         new_thread->saved_jmp_buf[0]._jb[2] = (int) (new_thread->stack + pattr->stacksize_attr - sizeof(double));
 213 #endif
 214 #elif   defined(__NetBSD__)
 215 #if     defined(__alpha__)
 216                         new_thread->saved_jmp_buf[4 + R_SP] = (long) new_thread->stack + pattr->stacksize_attr - sizeof(double);
 217 #else
 218                         new_thread->saved_jmp_buf[2] = (long) new_thread->stack + pattr->stacksize_attr - sizeof(double);
 219 #endif
 220 #else
 221 #error  "Don't recognize this operating system!"
 222 #endif
 223
 224                         /* Copy the thread attributes: */
 225                         memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr));
 226
 227                         /*
 228                          * Check if this thread is to inherit the scheduling
 229                          * attributes from its parent:
 230                          */
 231                         if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) {
 232                                 /* Copy the scheduling attributes: */
 233                                 new_thread->base_priority
 234                                     = _thread_run->base_priority;
 235                                 new_thread->attr.prio
 236                                     = _thread_run->base_priority;
 237                                 new_thread->attr.sched_policy
 238                                     = _thread_run->attr.sched_policy;
 239                         } else {
 240                                 /*
 241                                  * Use just the thread priority, leaving the
 242                                  * other scheduling attributes as their
 243                                  * default values:
 244                                  */
 245                                 new_thread->base_priority
 246                                     = new_thread->attr.prio;
 247                         }
 248                         new_thread->active_priority = new_thread->base_priority;
 249                         new_thread->inherited_priority = 0;
 250
 251                         /* Initialise the join queue for the new thread: */
 252                         TAILQ_INIT(&(new_thread->join_queue));
 253
 254                         /* Initialize the mutex queue: */
 255                         TAILQ_INIT(&new_thread->mutexq);
 256
 257                         /* Initialise hooks in the thread structure: */
 258                         new_thread->specific_data = NULL;
 259                         new_thread->cleanup = NULL;
 260                         new_thread->flags = 0;
 261                         new_thread->poll_data.nfds = 0;
 262                         new_thread->poll_data.fds = NULL;
 263
 264                         /*
 265                          * Defer signals to protect the scheduling queues
 266                          * from access by the signal handler:
 267                          */
 268                         _thread_kern_sig_defer();
 269
 270                         /*
 271                          * Check if the garbage collector thread
 272                          * needs to be started.
 273                          */
 274                         f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial);
 275
 276                         /* Add the thread to the linked list of all threads: */
 277                         TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle);
 278
 279                         if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) {
 280                                 new_thread->state = PS_SUSPENDED;
 281                                 PTHREAD_WAITQ_INSERT(new_thread);
 282                         } else {
 283                                 new_thread->state = PS_RUNNING;
 284                                 PTHREAD_PRIOQ_INSERT_TAIL(new_thread);
 285                         }
 286
 287                         /*
 288                          * Undefer and handle pending signals, yielding
 289                          * if necessary.
 290                          */
 291                         _thread_kern_sig_undefer();
 292
 293                         /* Return a pointer to the thread structure: */
 294                         (*thread) = new_thread;
 295
 296                         /* Schedule the new user thread: */
 297                         _thread_kern_sched(NULL);
 298
 299                         /*
 300                          * Start a garbage collector thread
 301                          * if necessary.
 302                          */
 303                         if (f_gc && pthread_create(&gc_thread,NULL,
 304                                     _thread_gc,NULL) != 0)
 305                                 PANIC("Can't create gc thread");
 306                 }
 307         }
 308
 309         /* Return the status: */
 310         return (ret);
 311 }
 312
 313 void
 314 _thread_start(void)
 315 {
 316         /* We just left the scheduler via longjmp: */
 317         _thread_kern_in_sched = 0;
 318
 319         /* Run the current thread's start routine with argument: */
 320         pthread_exit(_thread_run->start_routine(_thread_run->arg));
 321
 322         /* This point should never be reached. */
 323         PANIC("Thread has resumed after exit");
 324 }
 325 #endif