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  * $FreeBSD$
  28  */
  29
  30 #include "namespace.h"
  31 #include <sys/types.h>
  32 #include <sys/rtprio.h>
  33 #include <sys/signalvar.h>
  34 #include <errno.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <stddef.h>
  38 #include <pthread.h>
  39 #include <pthread_np.h>
  40 #include "un-namespace.h"
  41
  42 #include "thr_private.h"
  43
  44 static int  create_stack(struct pthread_attr *pattr);
  45 static void thread_start(struct pthread *curthread);
  46
  47 __weak_reference(_pthread_create, pthread_create);
  48
  49 int
  50 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
  51                void *(*start_routine) (void *), void *arg)
  52 {
  53         struct pthread *curthread, *new_thread;
  54         struct thr_param param;
  55         struct sched_param sched_param;
  56         struct rtprio rtp;
  57         int ret = 0, locked, create_suspended;
  58         sigset_t set, oset;
  59         cpuset_t *cpusetp = NULL;
  60         int cpusetsize = 0;
  61
  62         _thr_check_init();
  63
  64         /*
  65          * Tell libc and others now they need lock to protect their data.
  66          */
  67         if (_thr_isthreaded() == 0 && _thr_setthreaded(1))
  68                 return (EAGAIN);
  69
  70         curthread = _get_curthread();
  71         if ((new_thread = _thr_alloc(curthread)) == NULL)
  72                 return (EAGAIN);
  73
  74         memset(&param, 0, sizeof(param));
  75
  76         if (attr == NULL || *attr == NULL)
  77                 /* Use the default thread attributes: */
  78                 new_thread->attr = _pthread_attr_default;
  79         else {
  80                 new_thread->attr = *(*attr);
  81                 cpusetp = new_thread->attr.cpuset;
  82                 cpusetsize = new_thread->attr.cpusetsize;
  83                 new_thread->attr.cpuset = NULL;
  84                 new_thread->attr.cpusetsize = 0;
  85         }
  86         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  87                 /* inherit scheduling contention scope */
  88                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  89                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  90                 else
  91                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
  92
  93                 new_thread->attr.prio = curthread->attr.prio;
  94                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
  95         }
  96
  97         new_thread->tid = TID_TERMINATED;
  98
  99         if (create_stack(&new_thread->attr) != 0) {
 100                 /* Insufficient memory to create a stack: */
 101                 _thr_free(curthread, new_thread);
 102                 return (EAGAIN);
 103         }
 104         /*
 105          * Write a magic value to the thread structure
 106          * to help identify valid ones:
 107          */
 108         new_thread->magic = THR_MAGIC;
 109         new_thread->start_routine = start_routine;
 110         new_thread->arg = arg;
 111         new_thread->cancel_enable = 1;
 112         new_thread->cancel_async = 0;
 113         /* Initialize the mutex queue: */
 114         TAILQ_INIT(&new_thread->mutexq);
 115         TAILQ_INIT(&new_thread->pp_mutexq);
 116
 117         /* Initialise hooks in the thread structure: */
 118         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
 119                 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
 120                 create_suspended = 1;
 121         } else {
 122                 create_suspended = 0;
 123         }
 124
 125         new_thread->state = PS_RUNNING;
 126
 127         if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
 128                 new_thread->tlflags |= TLFLAGS_DETACHED;
 129
 130         if (curthread->in_sigcancel_handler)
 131                 new_thread->unblock_sigcancel = 1;
 132         else
 133                 new_thread->unblock_sigcancel = 0;
 134
 135         /* Add the new thread. */
 136         new_thread->refcount = 1;
 137         _thr_link(curthread, new_thread);
 138         /* Return thread pointer eariler so that new thread can use it. */
 139         (*thread) = new_thread;
 140         if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
 141                 THR_THREAD_LOCK(curthread, new_thread);
 142                 locked = 1;
 143         } else
 144                 locked = 0;
 145         param.start_func = (void (*)(void *)) thread_start;
 146         param.arg = new_thread;
 147         param.stack_base = new_thread->attr.stackaddr_attr;
 148         param.stack_size = new_thread->attr.stacksize_attr;
 149         param.tls_base = (char *)new_thread->tcb;
 150         param.tls_size = sizeof(struct tcb);
 151         param.child_tid = &new_thread->tid;
 152         param.parent_tid = &new_thread->tid;
 153         param.flags = 0;
 154         if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
 155                 param.flags |= THR_SYSTEM_SCOPE;
 156         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
 157                 param.rtp = NULL;
 158         else {
 159                 sched_param.sched_priority = new_thread->attr.prio;
 160                 _schedparam_to_rtp(new_thread->attr.sched_policy,
 161                         &sched_param, &rtp);
 162                 param.rtp = &rtp;
 163         }
 164
 165         /* Schedule the new thread. */
 166         if (create_suspended) {
 167                 SIGFILLSET(set);
 168                 SIGDELSET(set, SIGTRAP);
 169                 __sys_sigprocmask(SIG_SETMASK, &set, &oset);
 170                 new_thread->sigmask = oset;
 171                 SIGDELSET(new_thread->sigmask, SIGCANCEL);
 172         }
 173
 174         ret = thr_new(&param, sizeof(param));
 175
 176         if (ret != 0) {
 177                 ret = errno;
 178                 /*
 179                  * Translate EPROCLIM into well-known POSIX code EAGAIN.
 180                  */
 181                 if (ret == EPROCLIM)
 182                         ret = EAGAIN;
 183         }
 184
 185         if (create_suspended)
 186                 __sys_sigprocmask(SIG_SETMASK, &oset, NULL);
 187
 188         if (ret != 0) {
 189                 if (!locked)
 190                         THR_THREAD_LOCK(curthread, new_thread);
 191                 new_thread->state = PS_DEAD;
 192                 new_thread->tid = TID_TERMINATED;
 193                 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
 194                         new_thread->cycle++;
 195                         _thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
 196                 }
 197                 THR_THREAD_UNLOCK(curthread, new_thread);
 198                 THREAD_LIST_LOCK(curthread);
 199                 _thread_active_threads--;
 200                 new_thread->tlflags |= TLFLAGS_DETACHED;
 201                 _thr_ref_delete_unlocked(curthread, new_thread);
 202                 THREAD_LIST_UNLOCK(curthread);
 203         } else if (locked) {
 204                 if (cpusetp != NULL) {
 205                         if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
 206                                 TID(new_thread), cpusetsize, cpusetp)) {
 207                                 ret = errno;
 208                                 /* kill the new thread */
 209                                 new_thread->force_exit = 1;
 210                                 THR_THREAD_UNLOCK(curthread, new_thread);
 211                                 goto out;
 212                         }
 213                 }
 214
 215                 _thr_report_creation(curthread, new_thread);
 216                 THR_THREAD_UNLOCK(curthread, new_thread);
 217 out:
 218                 if (ret) {
 219                         THREAD_LIST_LOCK(curthread);
 220                         new_thread->tlflags |= TLFLAGS_DETACHED;
 221                         THR_GCLIST_ADD(new_thread);
 222                         THREAD_LIST_UNLOCK(curthread);
 223                 }
 224         }
 225
 226         if (ret)
 227                 (*thread) = 0;
 228         return (ret);
 229 }
 230
 231 static int
 232 create_stack(struct pthread_attr *pattr)
 233 {
 234         int ret;
 235
 236         /* Check if a stack was specified in the thread attributes: */
 237         if ((pattr->stackaddr_attr) != NULL) {
 238                 pattr->guardsize_attr = 0;
 239                 pattr->flags |= THR_STACK_USER;
 240                 ret = 0;
 241         }
 242         else
 243                 ret = _thr_stack_alloc(pattr);
 244         return (ret);
 245 }
 246
 247 static void
 248 thread_start(struct pthread *curthread)
 249 {
 250         sigset_t set;
 251
 252         if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
 253                 set = curthread->sigmask;
 254
 255         /*
 256          * This is used as a serialization point to allow parent
 257          * to report 'new thread' event to debugger or tweak new thread's
 258          * attributes before the new thread does real-world work.
 259          */
 260         THR_LOCK(curthread);
 261         THR_UNLOCK(curthread);
 262
 263         if (curthread->force_exit)
 264                 _pthread_exit(PTHREAD_CANCELED);
 265
 266         if (curthread->unblock_sigcancel) {
 267                 sigset_t set1;
 268
 269                 SIGEMPTYSET(set1);
 270                 SIGADDSET(set1, SIGCANCEL);
 271                 __sys_sigprocmask(SIG_UNBLOCK, &set1, NULL);
 272         }
 273
 274         if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
 275 #if 0
 276                 /* Done in THR_UNLOCK() */
 277                 _thr_ast(curthread);
 278 #endif
 279
 280                 /*
 281                  * Parent thread have stored signal mask for us,
 282                  * we should restore it now.
 283                  */
 284                 __sys_sigprocmask(SIG_SETMASK, &set, NULL);
 285         }
 286
 287         /* Run the current thread's start routine with argument: */
 288         _pthread_exit(curthread->start_routine(curthread->arg));
 289
 290         /* This point should never be reached. */
 291         PANIC("Thread has resumed after exit");
 292 }