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