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 * thread, const pthread_attr_t * attr,
  54                void *(*start_routine) (void *), void *arg)
  55 {
  56         struct pthread *curthread, *new_thread;
  57         struct thr_param param;
  58         struct sched_param sched_param;
  59         struct rtprio rtp;
  60         sigset_t set, oset;
  61         cpuset_t *cpusetp;
  62         int i, cpusetsize, create_suspended, locked, old_stack_prot, ret;
  63
  64         cpusetp = NULL;
  65         ret = cpusetsize = 0;
  66         _thr_check_init();
  67
  68         /*
  69          * Tell libc and others now they need lock to protect their data.
  70          */
  71         if (_thr_isthreaded() == 0) {
  72                 _malloc_first_thread();
  73                 if (_thr_setthreaded(1))
  74                         return (EAGAIN);
  75         }
  76
  77         curthread = _get_curthread();
  78         if ((new_thread = _thr_alloc(curthread)) == NULL)
  79                 return (EAGAIN);
  80
  81         memset(&param, 0, sizeof(param));
  82
  83         if (attr == NULL || *attr == NULL)
  84                 /* Use the default thread attributes: */
  85                 new_thread->attr = _pthread_attr_default;
  86         else {
  87                 new_thread->attr = *(*attr);
  88                 cpusetp = new_thread->attr.cpuset;
  89                 cpusetsize = new_thread->attr.cpusetsize;
  90                 new_thread->attr.cpuset = NULL;
  91                 new_thread->attr.cpusetsize = 0;
  92         }
  93         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  94                 /* inherit scheduling contention scope */
  95                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  96                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  97                 else
  98                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
  99
 100                 new_thread->attr.prio = curthread->attr.prio;
 101                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
 102         }
 103
 104         new_thread->tid = TID_TERMINATED;
 105
 106         old_stack_prot = _rtld_get_stack_prot();
 107         if (create_stack(&new_thread->attr) != 0) {
 108                 /* Insufficient memory to create a stack: */
 109                 _thr_free(curthread, new_thread);
 110                 return (EAGAIN);
 111         }
 112         /*
 113          * Write a magic value to the thread structure
 114          * to help identify valid ones:
 115          */
 116         new_thread->magic = THR_MAGIC;
 117         new_thread->start_routine = start_routine;
 118         new_thread->arg = arg;
 119         new_thread->cancel_enable = 1;
 120         new_thread->cancel_async = 0;
 121         /* Initialize the mutex queue: */
 122         for (i = 0; i < TMQ_NITEMS; i++)
 123                 TAILQ_INIT(&new_thread->mq[i]);
 124
 125         /* Initialise hooks in the thread structure: */
 126         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
 127                 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
 128                 create_suspended = 1;
 129         } else {
 130                 create_suspended = 0;
 131         }
 132
 133         new_thread->state = PS_RUNNING;
 134
 135         if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
 136                 new_thread->flags |= THR_FLAGS_DETACHED;
 137
 138         /* Add the new thread. */
 139         new_thread->refcount = 1;
 140         _thr_link(curthread, new_thread);
 141
 142         /*
 143          * Handle the race between __pthread_map_stacks_exec and
 144          * thread linkage.
 145          */
 146         if (old_stack_prot != _rtld_get_stack_prot())
 147                 _thr_stack_fix_protection(new_thread);
 148
 149         /* Return thread pointer eariler so that new thread can use it. */
 150         (*thread) = new_thread;
 151         if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
 152                 THR_THREAD_LOCK(curthread, new_thread);
 153                 locked = 1;
 154         } else
 155                 locked = 0;
 156         param.start_func = (void (*)(void *)) thread_start;
 157         param.arg = new_thread;
 158         param.stack_base = new_thread->attr.stackaddr_attr;
 159         param.stack_size = new_thread->attr.stacksize_attr;
 160         param.tls_base = (char *)new_thread->tcb;
 161         param.tls_size = sizeof(struct tcb);
 162         param.child_tid = &new_thread->tid;
 163         param.parent_tid = &new_thread->tid;
 164         param.flags = 0;
 165         if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
 166                 param.flags |= THR_SYSTEM_SCOPE;
 167         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
 168                 param.rtp = NULL;
 169         else {
 170                 sched_param.sched_priority = new_thread->attr.prio;
 171                 _schedparam_to_rtp(new_thread->attr.sched_policy,
 172                         &sched_param, &rtp);
 173                 param.rtp = &rtp;
 174         }
 175
 176         /* Schedule the new thread. */
 177         if (create_suspended) {
 178                 SIGFILLSET(set);
 179                 SIGDELSET(set, SIGTRAP);
 180                 __sys_sigprocmask(SIG_SETMASK, &set, &oset);
 181                 new_thread->sigmask = oset;
 182                 SIGDELSET(new_thread->sigmask, SIGCANCEL);
 183         }
 184
 185         ret = thr_new(&param, sizeof(param));
 186
 187         if (ret != 0) {
 188                 ret = errno;
 189                 /*
 190                  * Translate EPROCLIM into well-known POSIX code EAGAIN.
 191                  */
 192                 if (ret == EPROCLIM)
 193                         ret = EAGAIN;
 194         }
 195
 196         if (create_suspended)
 197                 __sys_sigprocmask(SIG_SETMASK, &oset, NULL);
 198
 199         if (ret != 0) {
 200                 if (!locked)
 201                         THR_THREAD_LOCK(curthread, new_thread);
 202                 new_thread->state = PS_DEAD;
 203                 new_thread->tid = TID_TERMINATED;
 204                 new_thread->flags |= THR_FLAGS_DETACHED;
 205                 new_thread->refcount--;
 206                 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
 207                         new_thread->cycle++;
 208                         _thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
 209                 }
 210                 _thr_try_gc(curthread, new_thread); /* thread lock released */
 211                 atomic_add_int(&_thread_active_threads, -1);
 212         } else if (locked) {
 213                 if (cpusetp != NULL) {
 214                         if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
 215                                 TID(new_thread), cpusetsize, cpusetp)) {
 216                                 ret = errno;
 217                                 /* kill the new thread */
 218                                 new_thread->force_exit = 1;
 219                                 new_thread->flags |= THR_FLAGS_DETACHED;
 220                                 _thr_try_gc(curthread, new_thread);
 221                                  /* thread lock released */
 222                                 goto out;
 223                         }
 224                 }
 225
 226                 _thr_report_creation(curthread, new_thread);
 227                 THR_THREAD_UNLOCK(curthread, new_thread);
 228         }
 229 out:
 230         if (ret)
 231                 (*thread) = 0;
 232         return (ret);
 233 }
 234
 235 static int
 236 create_stack(struct pthread_attr *pattr)
 237 {
 238         int ret;
 239
 240         /* Check if a stack was specified in the thread attributes: */
 241         if ((pattr->stackaddr_attr) != NULL) {
 242                 pattr->guardsize_attr = 0;
 243                 pattr->flags |= THR_STACK_USER;
 244                 ret = 0;
 245         }
 246         else
 247                 ret = _thr_stack_alloc(pattr);
 248         return (ret);
 249 }
 250
 251 static void
 252 thread_start(struct pthread *curthread)
 253 {
 254         sigset_t set;
 255
 256         if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
 257                 set = curthread->sigmask;
 258
 259         /*
 260          * This is used as a serialization point to allow parent
 261          * to report 'new thread' event to debugger or tweak new thread's
 262          * attributes before the new thread does real-world work.
 263          */
 264         THR_LOCK(curthread);
 265         THR_UNLOCK(curthread);
 266
 267         if (curthread->force_exit)
 268                 _pthread_exit(PTHREAD_CANCELED);
 269
 270         if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
 271 #if 0
 272                 /* Done in THR_UNLOCK() */
 273                 _thr_ast(curthread);
 274 #endif
 275
 276                 /*
 277                  * Parent thread have stored signal mask for us,
 278                  * we should restore it now.
 279                  */
 280                 __sys_sigprocmask(SIG_SETMASK, &set, NULL);
 281         }
 282
 283 #ifdef _PTHREAD_FORCED_UNWIND
 284         curthread->unwind_stackend = (char *)curthread->attr.stackaddr_attr +
 285                 curthread->attr.stacksize_attr;
 286 #endif
 287
 288         /* Run the current thread's start routine with argument: */
 289         _pthread_exit(curthread->start_routine(curthread->arg));
 290
 291         /* This point should never be reached. */
 292         PANIC("Thread has resumed after exit");
 293 }