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 <link.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <stddef.h>
  39 #include <pthread.h>
  40 #include <pthread_np.h>
  41 #include "un-namespace.h"
  42
  43 #include "libc_private.h"
  44 #include "thr_private.h"
  45
  46 static int  create_stack(struct pthread_attr *pattr);
  47 static void thread_start(struct pthread *curthread);
  48
  49 __weak_reference(_pthread_create, pthread_create);
  50
  51 int
  52 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
  53                void *(*start_routine) (void *), void *arg)
  54 {
  55         struct pthread *curthread, *new_thread;
  56         struct thr_param param;
  57         struct sched_param sched_param;
  58         struct rtprio rtp;
  59         int ret = 0, locked, create_suspended;
  60         sigset_t set, oset;
  61         cpuset_t *cpusetp = NULL;
  62         int cpusetsize = 0;
  63         int old_stack_prot;
  64
  65         _thr_check_init();
  66
  67         /*
  68          * Tell libc and others now they need lock to protect their data.
  69          */
  70         if (_thr_isthreaded() == 0) {
  71                 _malloc_first_thread();
  72                 if (_thr_setthreaded(1))
  73                         return (EAGAIN);
  74         }
  75
  76         curthread = _get_curthread();
  77         if ((new_thread = _thr_alloc(curthread)) == NULL)
  78                 return (EAGAIN);
  79
  80         memset(&param, 0, sizeof(param));
  81
  82         if (attr == NULL || *attr == NULL)
  83                 /* Use the default thread attributes: */
  84                 new_thread->attr = _pthread_attr_default;
  85         else {
  86                 new_thread->attr = *(*attr);
  87                 cpusetp = new_thread->attr.cpuset;
  88                 cpusetsize = new_thread->attr.cpusetsize;
  89                 new_thread->attr.cpuset = NULL;
  90                 new_thread->attr.cpusetsize = 0;
  91         }
  92         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  93                 /* inherit scheduling contention scope */
  94                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  95                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  96                 else
  97                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
  98
  99                 new_thread->attr.prio = curthread->attr.prio;
 100                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
 101         }
 102
 103         new_thread->tid = TID_TERMINATED;
 104
 105         old_stack_prot = _rtld_get_stack_prot();
 106         if (create_stack(&new_thread->attr) != 0) {
 107                 /* Insufficient memory to create a stack: */
 108                 _thr_free(curthread, new_thread);
 109                 return (EAGAIN);
 110         }
 111         /*
 112          * Write a magic value to the thread structure
 113          * to help identify valid ones:
 114          */
 115         new_thread->magic = THR_MAGIC;
 116         new_thread->start_routine = start_routine;
 117         new_thread->arg = arg;
 118         new_thread->cancel_enable = 1;
 119         new_thread->cancel_async = 0;
 120         /* Initialize the mutex queue: */
 121         TAILQ_INIT(&new_thread->mutexq);
 122         TAILQ_INIT(&new_thread->pp_mutexq);
 123
 124         /* Initialise hooks in the thread structure: */
 125         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
 126                 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
 127                 create_suspended = 1;
 128         } else {
 129                 create_suspended = 0;
 130         }
 131
 132         new_thread->state = PS_RUNNING;
 133
 134         if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
 135                 new_thread->flags |= THR_FLAGS_DETACHED;
 136
 137         /* Add the new thread. */
 138         new_thread->refcount = 1;
 139         _thr_link(curthread, new_thread);
 140
 141         /*
 142          * Handle the race between __pthread_map_stacks_exec and
 143          * thread linkage.
 144          */
 145         if (old_stack_prot != _rtld_get_stack_prot())
 146                 _thr_stack_fix_protection(new_thread);
 147
 148         /* Return thread pointer eariler so that new thread can use it. */
 149         (*thread) = new_thread;
 150         if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
 151                 THR_THREAD_LOCK(curthread, new_thread);
 152                 locked = 1;
 153         } else
 154                 locked = 0;
 155         param.start_func = (void (*)(void *)) thread_start;
 156         param.arg = new_thread;
 157         param.stack_base = new_thread->attr.stackaddr_attr;
 158         param.stack_size = new_thread->attr.stacksize_attr;
 159         param.tls_base = (char *)new_thread->tcb;
 160         param.tls_size = sizeof(struct tcb);
 161         param.child_tid = &new_thread->tid;
 162         param.parent_tid = &new_thread->tid;
 163         param.flags = 0;
 164         if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
 165                 param.flags |= THR_SYSTEM_SCOPE;
 166         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
 167                 param.rtp = NULL;
 168         else {
 169                 sched_param.sched_priority = new_thread->attr.prio;
 170                 _schedparam_to_rtp(new_thread->attr.sched_policy,
 171                         &sched_param, &rtp);
 172                 param.rtp = &rtp;
 173         }
 174
 175         /* Schedule the new thread. */
 176         if (create_suspended) {
 177                 SIGFILLSET(set);
 178                 SIGDELSET(set, SIGTRAP);
 179                 __sys_sigprocmask(SIG_SETMASK, &set, &oset);
 180                 new_thread->sigmask = oset;
 181                 SIGDELSET(new_thread->sigmask, SIGCANCEL);
 182         }
 183
 184         ret = thr_new(&param, sizeof(param));
 185
 186         if (ret != 0) {
 187                 ret = errno;
 188                 /*
 189                  * Translate EPROCLIM into well-known POSIX code EAGAIN.
 190                  */
 191                 if (ret == EPROCLIM)
 192                         ret = EAGAIN;
 193         }
 194
 195         if (create_suspended)
 196                 __sys_sigprocmask(SIG_SETMASK, &oset, NULL);
 197
 198         if (ret != 0) {
 199                 if (!locked)
 200                         THR_THREAD_LOCK(curthread, new_thread);
 201                 new_thread->state = PS_DEAD;
 202                 new_thread->tid = TID_TERMINATED;
 203                 new_thread->flags |= THR_FLAGS_DETACHED;
 204                 new_thread->refcount--;
 205                 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
 206                         new_thread->cycle++;
 207                         _thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
 208                 }
 209                 _thr_try_gc(curthread, new_thread); /* thread lock released */
 210                 atomic_add_int(&_thread_active_threads, -1);
 211         } else if (locked) {
 212                 if (cpusetp != NULL) {
 213                         if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
 214                                 TID(new_thread), cpusetsize, cpusetp)) {
 215                                 ret = errno;
 216                                 /* kill the new thread */
 217                                 new_thread->force_exit = 1;
 218                                 new_thread->flags |= THR_FLAGS_DETACHED;
 219                                 _thr_try_gc(curthread, new_thread);
 220                                  /* thread lock released */
 221                                 goto out;
 222                         }
 223                 }
 224
 225                 _thr_report_creation(curthread, new_thread);
 226                 THR_THREAD_UNLOCK(curthread, new_thread);
 227         }
 228 out:
 229         if (ret)
 230                 (*thread) = 0;
 231         return (ret);
 232 }
 233
 234 static int
 235 create_stack(struct pthread_attr *pattr)
 236 {
 237         int ret;
 238
 239         /* Check if a stack was specified in the thread attributes: */
 240         if ((pattr->stackaddr_attr) != NULL) {
 241                 pattr->guardsize_attr = 0;
 242                 pattr->flags |= THR_STACK_USER;
 243                 ret = 0;
 244         }
 245         else
 246                 ret = _thr_stack_alloc(pattr);
 247         return (ret);
 248 }
 249
 250 static void
 251 thread_start(struct pthread *curthread)
 252 {
 253         sigset_t set;
 254
 255         if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
 256                 set = curthread->sigmask;
 257
 258         /*
 259          * This is used as a serialization point to allow parent
 260          * to report 'new thread' event to debugger or tweak new thread's
 261          * attributes before the new thread does real-world work.
 262          */
 263         THR_LOCK(curthread);
 264         THR_UNLOCK(curthread);
 265
 266         if (curthread->force_exit)
 267                 _pthread_exit(PTHREAD_CANCELED);
 268
 269         if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
 270 #if 0
 271                 /* Done in THR_UNLOCK() */
 272                 _thr_ast(curthread);
 273 #endif
 274
 275                 /*
 276                  * Parent thread have stored signal mask for us,
 277                  * we should restore it now.
 278                  */
 279                 __sys_sigprocmask(SIG_SETMASK, &set, NULL);
 280         }
 281
 282 #ifdef _PTHREAD_FORCED_UNWIND
 283         curthread->unwind_stackend = (char *)curthread->attr.stackaddr_attr +
 284                 curthread->attr.stacksize_attr;
 285 #endif
 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 }