lib/libthr/thread/thr_create.c

   1 /*
   2  * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
   3  * Copyright (c) 2005, David Xu <davidxu@freebsd.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice unmodified, this list of conditions, and the following
  11  *    disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include <sys/cdefs.h>
  29 __FBSDID("$FreeBSD$");
  30
  31 #include "namespace.h"
  32 #include <sys/types.h>
  33 #include <sys/rtprio.h>
  34 #include <sys/signalvar.h>
  35 #include <errno.h>
  36 #include <link.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <stddef.h>
  40 #include <pthread.h>
  41 #include <pthread_np.h>
  42 #include "un-namespace.h"
  43
  44 #include "libc_private.h"
  45 #include "thr_private.h"
  46
  47 static int  create_stack(struct pthread_attr *pattr);
  48 static void thread_start(struct pthread *curthread);
  49
  50 __weak_reference(_pthread_create, pthread_create);
  51
  52 int
  53 _pthread_create(pthread_t * __restrict thread,
  54     const pthread_attr_t * __restrict attr, void *(*start_routine) (void *),
  55     void * __restrict arg)
  56 {
  57         struct pthread *curthread, *new_thread;
  58         struct thr_param param;
  59         struct sched_param sched_param;
  60         struct rtprio rtp;
  61         sigset_t set, oset;
  62         cpuset_t *cpusetp;
  63         int i, cpusetsize, create_suspended, locked, old_stack_prot, ret;
  64
  65         cpusetp = NULL;
  66         ret = cpusetsize = 0;
  67         _thr_check_init();
  68
  69         /*
  70          * Tell libc and others now they need lock to protect their data.
  71          */
  72         if (_thr_isthreaded() == 0) {
  73                 _malloc_first_thread();
  74                 if (_thr_setthreaded(1))
  75                         return (EAGAIN);
  76         }
  77
  78         curthread = _get_curthread();
  79         if ((new_thread = _thr_alloc(curthread)) == NULL)
  80                 return (EAGAIN);
  81
  82         memset(&param, 0, sizeof(param));
  83
  84         if (attr == NULL || *attr == NULL)
  85                 /* Use the default thread attributes: */
  86                 new_thread->attr = _pthread_attr_default;
  87         else {
  88                 new_thread->attr = *(*attr);
  89                 cpusetp = new_thread->attr.cpuset;
  90                 cpusetsize = new_thread->attr.cpusetsize;
  91                 new_thread->attr.cpuset = NULL;
  92                 new_thread->attr.cpusetsize = 0;
  93         }
  94         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  95                 /* inherit scheduling contention scope */
  96                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  97                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  98                 else
  99                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
 100
 101                 new_thread->attr.prio = curthread->attr.prio;
 102                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
 103         }
 104
 105         new_thread->tid = TID_TERMINATED;
 106
 107         old_stack_prot = _rtld_get_stack_prot();
 108         if (create_stack(&new_thread->attr) != 0) {
 109                 /* Insufficient memory to create a stack: */
 110                 _thr_free(curthread, new_thread);
 111                 return (EAGAIN);
 112         }
 113         /*
 114          * Write a magic value to the thread structure
 115          * to help identify valid ones:
 116          */
 117         new_thread->magic = THR_MAGIC;
 118         new_thread->start_routine = start_routine;
 119         new_thread->arg = arg;
 120         new_thread->cancel_enable = 1;
 121         new_thread->cancel_async = 0;
 122         /* Initialize the mutex queue: */
 123         for (i = 0; i < TMQ_NITEMS; i++)
 124                 TAILQ_INIT(&new_thread->mq[i]);
 125
 126         /* Initialise hooks in the thread structure: */
 127         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
 128                 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
 129                 create_suspended = 1;
 130         } else {
 131                 create_suspended = 0;
 132         }
 133
 134         new_thread->state = PS_RUNNING;
 135
 136         if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
 137                 new_thread->flags |= THR_FLAGS_DETACHED;
 138
 139         /* Add the new thread. */
 140         new_thread->refcount = 1;
 141         _thr_link(curthread, new_thread);
 142
 143         /*
 144          * Handle the race between __pthread_map_stacks_exec and
 145          * thread linkage.
 146          */
 147         if (old_stack_prot != _rtld_get_stack_prot())
 148                 _thr_stack_fix_protection(new_thread);
 149
 150         /* Return thread pointer eariler so that new thread can use it. */
 151         (*thread) = new_thread;
 152         if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
 153                 THR_THREAD_LOCK(curthread, new_thread);
 154                 locked = 1;
 155         } else
 156                 locked = 0;
 157         param.start_func = (void (*)(void *)) thread_start;
 158         param.arg = new_thread;
 159         param.stack_base = new_thread->attr.stackaddr_attr;
 160         param.stack_size = new_thread->attr.stacksize_attr;
 161         param.tls_base = (char *)new_thread->tcb;
 162         param.tls_size = sizeof(struct tcb);
 163         param.child_tid = &new_thread->tid;
 164         param.parent_tid = &new_thread->tid;
 165         param.flags = 0;
 166         if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
 167                 param.flags |= THR_SYSTEM_SCOPE;
 168         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
 169                 param.rtp = NULL;
 170         else {
 171                 sched_param.sched_priority = new_thread->attr.prio;
 172                 _schedparam_to_rtp(new_thread->attr.sched_policy,
 173                         &sched_param, &rtp);
 174                 param.rtp = &rtp;
 175         }
 176
 177         /* Schedule the new thread. */
 178         if (create_suspended) {
 179                 SIGFILLSET(set);
 180                 SIGDELSET(set, SIGTRAP);
 181                 __sys_sigprocmask(SIG_SETMASK, &set, &oset);
 182                 new_thread->sigmask = oset;
 183                 SIGDELSET(new_thread->sigmask, SIGCANCEL);
 184         }
 185
 186         ret = thr_new(&param, sizeof(param));
 187
 188         if (ret != 0) {
 189                 ret = errno;
 190                 /*
 191                  * Translate EPROCLIM into well-known POSIX code EAGAIN.
 192                  */
 193                 if (ret == EPROCLIM)
 194                         ret = EAGAIN;
 195         }
 196
 197         if (create_suspended)
 198                 __sys_sigprocmask(SIG_SETMASK, &oset, NULL);
 199
 200         if (ret != 0) {
 201                 if (!locked)
 202                         THR_THREAD_LOCK(curthread, new_thread);
 203                 new_thread->state = PS_DEAD;
 204                 new_thread->tid = TID_TERMINATED;
 205                 new_thread->flags |= THR_FLAGS_DETACHED;
 206                 new_thread->refcount--;
 207                 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
 208                         new_thread->cycle++;
 209                         _thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
 210                 }
 211                 _thr_try_gc(curthread, new_thread); /* thread lock released */
 212                 atomic_add_int(&_thread_active_threads, -1);
 213         } else if (locked) {
 214                 if (cpusetp != NULL) {
 215                         if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
 216                                 TID(new_thread), cpusetsize, cpusetp)) {
 217                                 ret = errno;
 218                                 /* kill the new thread */
 219                                 new_thread->force_exit = 1;
 220                                 new_thread->flags |= THR_FLAGS_DETACHED;
 221                                 _thr_try_gc(curthread, new_thread);
 222                                  /* thread lock released */
 223                                 goto out;
 224                         }
 225                 }
 226
 227                 _thr_report_creation(curthread, new_thread);
 228                 THR_THREAD_UNLOCK(curthread, new_thread);
 229         }
 230 out:
 231         if (ret)
 232                 (*thread) = 0;
 233         return (ret);
 234 }
 235
 236 static int
 237 create_stack(struct pthread_attr *pattr)
 238 {
 239         int ret;
 240
 241         /* Check if a stack was specified in the thread attributes: */
 242         if ((pattr->stackaddr_attr) != NULL) {
 243                 pattr->guardsize_attr = 0;
 244                 pattr->flags |= THR_STACK_USER;
 245                 ret = 0;
 246         }
 247         else
 248                 ret = _thr_stack_alloc(pattr);
 249         return (ret);
 250 }
 251
 252 static void
 253 thread_start(struct pthread *curthread)
 254 {
 255         sigset_t set;
 256
 257         if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
 258                 set = curthread->sigmask;
 259
 260         /*
 261          * This is used as a serialization point to allow parent
 262          * to report 'new thread' event to debugger or tweak new thread's
 263          * attributes before the new thread does real-world work.
 264          */
 265         THR_LOCK(curthread);
 266         THR_UNLOCK(curthread);
 267
 268         if (curthread->force_exit)
 269                 _pthread_exit(PTHREAD_CANCELED);
 270
 271         if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
 272 #if 0
 273                 /* Done in THR_UNLOCK() */
 274                 _thr_ast(curthread);
 275 #endif
 276
 277                 /*
 278                  * Parent thread have stored signal mask for us,
 279                  * we should restore it now.
 280                  */
 281                 __sys_sigprocmask(SIG_SETMASK, &set, NULL);
 282         }
 283
 284 #ifdef _PTHREAD_FORCED_UNWIND
 285         curthread->unwind_stackend = (char *)curthread->attr.stackaddr_attr +
 286                 curthread->attr.stacksize_attr;
 287 #endif
 288
 289         /* Run the current thread's start routine with argument: */
 290         _pthread_exit(curthread->start_routine(curthread->arg));
 291
 292         /* This point should never be reached. */
 293         PANIC("Thread has resumed after exit");
 294 }