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