lib/libc_r/uthread/uthread_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: src/lib/libc_r/uthread/uthread_create.c,v 1.24.2.6 2003/01/08 05:04:26 fjoe Exp $
  33  * $DragonFly: src/lib/libc_r/uthread/uthread_create.c,v 1.6 2005/05/30 20:50:53 joerg Exp $
  34  */
  35 #include <errno.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <fcntl.h>
  39 #include <unistd.h>
  40 #include <stddef.h>
  41 #include <sys/time.h>
  42 #include <sys/param.h>
  43 #include <sys/mman.h>
  44 #include <machine/reg.h>
  45 #include <pthread.h>
  46 #include "pthread_private.h"
  47 #include "libc_private.h"
  48
  49 static u_int64_t next_uniqueid = 1;
  50
  51 #define OFF(f)  offsetof(struct pthread, f)
  52 int _thread_next_offset                 = OFF(tle.tqe_next);
  53 int _thread_uniqueid_offset             = OFF(uniqueid);
  54 int _thread_state_offset                = OFF(state);
  55 int _thread_name_offset                 = OFF(name);
  56 int _thread_ctx_offset                  = OFF(ctx);
  57 #undef OFF
  58
  59 int _thread_PS_RUNNING_value            = PS_RUNNING;
  60 int _thread_PS_DEAD_value               = PS_DEAD;
  61
  62 int
  63 _pthread_create(pthread_t *thread, const pthread_attr_t *attr,
  64                void *(*start_routine) (void *), void *arg)
  65 {
  66         struct pthread  *curthread = _get_curthread();
  67         struct itimerval itimer;
  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         if (thread == NULL)
  76                 return (EINVAL);
  77
  78         /*
  79          * Locking functions in libc are required when there are
  80          * threads other than the initial thread.
  81          */
  82         __isthreaded = 1;
  83
  84         /* Allocate memory for the thread structure: */
  85         if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) {
  86                 /* Insufficient memory to create a thread: */
  87                 ret = EAGAIN;
  88         } else {
  89                 /* Check if default thread attributes are required: */
  90                 if (attr == NULL || *attr == NULL) {
  91                         /* Use the default thread attributes: */
  92                         pattr = &pthread_attr_default;
  93                 } else {
  94                         pattr = *attr;
  95                 }
  96                 /* Check if a stack was specified in the thread attributes: */
  97                 if ((stack = pattr->stackaddr_attr) != NULL) {
  98                 }
  99                 /* Allocate memory for a default-size stack: */
 100                 else if (pattr->stacksize_attr == PTHREAD_STACK_DEFAULT) {
 101                         struct stack    *spare_stack;
 102
 103                         /* Allocate or re-use a default-size stack. */
 104
 105                         /*
 106                          * Use the garbage collector mutex for synchronization
 107                          * of the spare stack list.
 108                          */
 109                         if (pthread_mutex_lock(&_gc_mutex) != 0)
 110                                 PANIC("Cannot lock gc mutex");
 111
 112                         if ((spare_stack = SLIST_FIRST(&_stackq)) != NULL) {
 113                                 /* Use the spare stack. */
 114                                 SLIST_REMOVE_HEAD(&_stackq, qe);
 115
 116                                 /* Unlock the garbage collector mutex. */
 117                                 if (pthread_mutex_unlock(&_gc_mutex) != 0)
 118                                         PANIC("Cannot unlock gc mutex");
 119
 120                                 stack = sizeof(struct stack)
 121                                     + (void *) spare_stack
 122                                     - PTHREAD_STACK_DEFAULT;
 123                         } else {
 124                                 /* Allocate a new stack. */
 125                                 stack = _next_stack + PTHREAD_STACK_GUARD;
 126
 127                                 /*
 128                                  * Even if stack allocation fails, we don't want
 129                                  * to try to use this location again, so
 130                                  * unconditionally decrement _next_stack.  Under
 131                                  * normal operating conditions, the most likely
 132                                  * reason for an mmap() error is a stack
 133                                  * overflow of the adjacent thread stack.
 134                                  */
 135                                 _next_stack -= (PTHREAD_STACK_DEFAULT
 136                                     + PTHREAD_STACK_GUARD);
 137
 138                                 /* Unlock the garbage collector mutex. */
 139                                 if (pthread_mutex_unlock(&_gc_mutex) != 0)
 140                                         PANIC("Cannot unlock gc mutex");
 141
 142                                 /* Stack: */
 143                                 if (mmap(stack, PTHREAD_STACK_DEFAULT,
 144                                     PROT_READ | PROT_WRITE, MAP_STACK,
 145                                     -1, 0) == MAP_FAILED) {
 146                                         ret = EAGAIN;
 147                                         free(new_thread);
 148                                 }
 149                         }
 150                 }
 151                 /*
 152                  * The user wants a stack of a particular size.  Lets hope they
 153                  * really know what they want, and simply malloc the stack.
 154                  */
 155                 else if ((stack = (void *) malloc(pattr->stacksize_attr))
 156                     == NULL) {
 157                         /* Insufficient memory to create a thread: */
 158                         ret = EAGAIN;
 159                         free(new_thread);
 160                 }
 161
 162                 /* Check for errors: */
 163                 if (ret != 0) {
 164                 } else {
 165                         /* Initialise the thread structure: */
 166                         memset(new_thread, 0, sizeof(struct pthread));
 167                         new_thread->tcb = _libc_allocate_tls();
 168                         if (new_thread->tcb == NULL)
 169                                 PANIC("Cannot allocate TLS and TCB");
 170                         new_thread->slice_usec = -1;
 171                         new_thread->stack = stack;
 172                         new_thread->start_routine = start_routine;
 173                         new_thread->arg = arg;
 174
 175                         new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
 176                             PTHREAD_CANCEL_DEFERRED;
 177
 178                         /*
 179                          * Write a magic value to the thread structure
 180                          * to help identify valid ones:
 181                          */
 182                         new_thread->magic = PTHREAD_MAGIC;
 183
 184                         /* Initialise the thread for signals: */
 185                         new_thread->sigmask = curthread->sigmask;
 186                         new_thread->sigmask_seqno = 0;
 187
 188                         /* Initialize the signal frame: */
 189                         new_thread->curframe = NULL;
 190
 191                         /* Initialise the jump buffer: */
 192                         _setjmp(new_thread->ctx.jb);
 193
 194                         /*
 195                          * Set up new stack frame so that it looks like it
 196                          * returned from a longjmp() to the beginning of
 197                          * _thread_start().
 198                          */
 199                         SET_RETURN_ADDR_JB(new_thread->ctx.jb, _thread_start);
 200
 201                         /* The stack starts high and builds down: */
 202                         SET_STACK_JB(new_thread->ctx.jb,
 203                             (long)new_thread->stack + pattr->stacksize_attr
 204                             - sizeof(double));
 205
 206                         /* Copy the thread attributes: */
 207                         memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr));
 208
 209                         /*
 210                          * Check if this thread is to inherit the scheduling
 211                          * attributes from its parent:
 212                          */
 213                         if (new_thread->attr.sched_inherit & PTHREAD_INHERIT_SCHED) {
 214                                 /* Copy the scheduling attributes: */
 215                                 new_thread->base_priority =
 216                                     curthread->base_priority &
 217                                     ~PTHREAD_SIGNAL_PRIORITY;
 218                                 new_thread->attr.prio =
 219                                     curthread->base_priority &
 220                                     ~PTHREAD_SIGNAL_PRIORITY;
 221                                 new_thread->attr.sched_policy =
 222                                     curthread->attr.sched_policy;
 223                         } else {
 224                                 /*
 225                                  * Use just the thread priority, leaving the
 226                                  * other scheduling attributes as their
 227                                  * default values:
 228                                  */
 229                                 new_thread->base_priority =
 230                                     new_thread->attr.prio;
 231                         }
 232                         new_thread->active_priority = new_thread->base_priority;
 233                         new_thread->inherited_priority = 0;
 234
 235                         /* Initialize joiner to NULL (no joiner): */
 236                         new_thread->joiner = NULL;
 237
 238                         /* Initialize the mutex queue: */
 239                         TAILQ_INIT(&new_thread->mutexq);
 240
 241                         /* Initialise hooks in the thread structure: */
 242                         new_thread->specific_data = NULL;
 243                         new_thread->cleanup = NULL;
 244                         new_thread->flags = 0;
 245                         new_thread->poll_data.nfds = 0;
 246                         new_thread->poll_data.fds = NULL;
 247                         new_thread->continuation = NULL;
 248
 249                         /*
 250                          * Defer signals to protect the scheduling queues
 251                          * from access by the signal handler:
 252                          */
 253                         _thread_kern_sig_defer();
 254
 255                         /*
 256                          * Initialise the unique id which GDB uses to
 257                          * track threads.
 258                          */
 259                         new_thread->uniqueid = next_uniqueid++;
 260
 261                         /*
 262                          * Check if the garbage collector thread
 263                          * needs to be started.
 264                          */
 265                         f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial);
 266
 267                         /* Add the thread to the linked list of all threads: */
 268                         TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle);
 269
 270                         if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) {
 271                                 new_thread->flags |= PTHREAD_FLAGS_SUSPENDED;
 272                                 new_thread->state = PS_SUSPENDED;
 273                         } else {
 274                                 new_thread->state = PS_RUNNING;
 275                                 PTHREAD_PRIOQ_INSERT_TAIL(new_thread);
 276                         }
 277
 278                         /*
 279                          * Undefer and handle pending signals, yielding
 280                          * if necessary.
 281                          */
 282                         _thread_kern_sig_undefer();
 283
 284                         /* Return a pointer to the thread structure: */
 285                         (*thread) = new_thread;
 286
 287                         if (f_gc != 0) {
 288                                 /* Install the scheduling timer: */
 289                                 itimer.it_interval.tv_sec = 0;
 290                                 itimer.it_interval.tv_usec = _clock_res_usec;
 291                                 itimer.it_value = itimer.it_interval;
 292                                 if (setitimer(_ITIMER_SCHED_TIMER, &itimer,
 293                                     NULL) != 0)
 294                                         PANIC("Cannot set interval timer");
 295                         }
 296
 297                         /* Schedule the new user thread: */
 298                         _thread_kern_sched(NULL);
 299
 300                         /*
 301                          * Start a garbage collector thread
 302                          * if necessary.
 303                          */
 304                         if (f_gc && pthread_create(&gc_thread,NULL,
 305                                     _thread_gc,NULL) != 0)
 306                                 PANIC("Can't create gc thread");
 307
 308                 }
 309         }
 310
 311         /* Return the status: */
 312         return (ret);
 313 }
 314
 315 void
 316 _thread_start(void)
 317 {
 318         struct pthread  *curthread = _get_curthread();
 319
 320         /* We just left the scheduler via longjmp: */
 321         _thread_kern_in_sched = 0;
 322
 323         /* Run the current thread's start routine with argument: */
 324         pthread_exit(curthread->start_routine(curthread->arg));
 325
 326         /* This point should never be reached. */
 327         PANIC("Thread has resumed after exit");
 328 }
 329
 330 __strong_reference(_pthread_create, pthread_create);