lib/libthread_xu/thread/thr_create.c

   1 /*
   2  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
   3  * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
   4  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following 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  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by John Birrell.
  18  * 4. Neither the name of the author nor the names of any co-contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $FreeBSD: src/lib/libpthread/thread/thr_create.c,v 1.58 2004/10/23 23:28:36 davidxu Exp $
  35  */
  36
  37 #include "namespace.h"
  38 #include <errno.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <fcntl.h>
  42 #include <unistd.h>
  43 #include <stddef.h>
  44 #include <sys/time.h>
  45 #include <machine/reg.h>
  46 #include <machine/tls.h>
  47
  48 #include <pthread.h>
  49 #include <sys/signalvar.h>
  50 #include "un-namespace.h"
  51
  52 #include "thr_private.h"
  53 #include "libc_private.h"
  54
  55 static int  create_stack(struct pthread_attr *pattr);
  56 static void thread_start(void *);
  57
  58 int
  59 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
  60        void *(*start_routine) (void *), void *arg)
  61 {
  62         struct lwp_params create_params;
  63         void *stack;
  64         sigset_t sigmask, oldsigmask;
  65         struct pthread *curthread, *new_thread;
  66         int ret = 0, locked;
  67
  68         _thr_check_init();
  69
  70         /*
  71          * Tell libc and others now they need lock to protect their data.
  72          */
  73         if (_thr_isthreaded() == 0 && _thr_setthreaded(1))
  74                 return (EAGAIN);
  75
  76         curthread = tls_get_curthread();
  77         if ((new_thread = _thr_alloc(curthread)) == NULL)
  78                 return (EAGAIN);
  79
  80         if (attr == NULL || *attr == NULL)
  81                 /* Use the default thread attributes: */
  82                 new_thread->attr = _pthread_attr_default;
  83         else
  84                 new_thread->attr = *(*attr);
  85         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  86                 /* inherit scheduling contention scope */
  87                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  88                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  89                 else
  90                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
  91                 /*
  92                  * scheduling policy and scheduling parameters will be
  93                  * inherited in following code.
  94                  */
  95         }
  96
  97         if (_thread_scope_system > 0)
  98                 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  99         else if (_thread_scope_system < 0)
 100                 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
 101
 102         if (create_stack(&new_thread->attr) != 0) {
 103                 /* Insufficient memory to create a stack: */
 104                 new_thread->terminated = 1;
 105                 _thr_free(curthread, new_thread);
 106                 return (EAGAIN);
 107         }
 108         /*
 109          * Write a magic value to the thread structure
 110          * to help identify valid ones:
 111          */
 112         new_thread->magic = THR_MAGIC;
 113         new_thread->start_routine = start_routine;
 114         new_thread->arg = arg;
 115         new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
 116             PTHREAD_CANCEL_DEFERRED;
 117         /*
 118          * Check if this thread is to inherit the scheduling
 119          * attributes from its parent:
 120          */
 121         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
 122                 /*
 123                  * Copy the scheduling attributes. Lock the scheduling
 124                  * lock to get consistent scheduling parameters.
 125                  */
 126                 THR_LOCK(curthread);
 127                 new_thread->base_priority = curthread->base_priority;
 128                 new_thread->attr.prio = curthread->attr.prio;
 129                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
 130                 THR_UNLOCK(curthread);
 131         } else {
 132                 /*
 133                  * Use just the thread priority, leaving the
 134                  * other scheduling attributes as their
 135                  * default values:
 136                  */
 137                 new_thread->base_priority = new_thread->attr.prio;
 138         }
 139         new_thread->active_priority = new_thread->base_priority;
 140
 141         /* Initialize the mutex queue: */
 142         TAILQ_INIT(&new_thread->mutexq);
 143
 144         /* Initialise hooks in the thread structure: */
 145         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED)
 146                 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
 147
 148         new_thread->state = PS_RUNNING;
 149
 150         if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
 151                 new_thread->tlflags |= TLFLAGS_DETACHED;
 152
 153         /* Add the new thread. */
 154         new_thread->refcount = 1;
 155         _thr_link(curthread, new_thread);
 156         /* Return thread pointer eariler so that new thread can use it. */
 157         (*thread) = new_thread;
 158         if (SHOULD_REPORT_EVENT(curthread, TD_CREATE)) {
 159                 THR_THREAD_LOCK(curthread, new_thread);
 160                 locked = 1;
 161         } else
 162                 locked = 0;
 163         /* Schedule the new thread. */
 164         stack = (char *)new_thread->attr.stackaddr_attr +
 165                         new_thread->attr.stacksize_attr;
 166         bzero(&create_params, sizeof(create_params));
 167         create_params.lwp_func = thread_start;
 168         create_params.lwp_arg = new_thread;
 169         create_params.lwp_stack = stack;
 170         create_params.lwp_tid1 = &new_thread->tid;
 171         /*
 172          * Thread created by thr_create() inherits currrent thread
 173          * sigmask, however, before new thread setup itself correctly,
 174          * it can not handle signal, so we should mask all signals here.
 175          * We do this at the very last moment, so that we don't run
 176          * into problems while we have all signals disabled.
 177          */
 178         SIGFILLSET(sigmask);
 179         __sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask);
 180         new_thread->sigmask = oldsigmask;
 181         ret = lwp_create(&create_params);
 182         __sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL);
 183         if (ret != 0) {
 184                 if (!locked)
 185                         THR_THREAD_LOCK(curthread, new_thread);
 186                 new_thread->state = PS_DEAD;
 187                 new_thread->terminated = 1;
 188                 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
 189                         new_thread->cycle++;
 190                         _thr_umtx_wake(&new_thread->cycle, INT_MAX);
 191                 }
 192                 THR_THREAD_UNLOCK(curthread, new_thread);
 193                 THREAD_LIST_LOCK(curthread);
 194                 _thread_active_threads--;
 195                 new_thread->tlflags |= TLFLAGS_DETACHED;
 196                 _thr_ref_delete_unlocked(curthread, new_thread);
 197                 THREAD_LIST_UNLOCK(curthread);
 198                 (*thread) = NULL;
 199                 ret = EAGAIN;
 200         } else if (locked) {
 201                 _thr_report_creation(curthread, new_thread);
 202                 THR_THREAD_UNLOCK(curthread, new_thread);
 203         }
 204         return (ret);
 205 }
 206
 207 static int
 208 create_stack(struct pthread_attr *pattr)
 209 {
 210         int ret;
 211
 212         /* Check if a stack was specified in the thread attributes: */
 213         if ((pattr->stackaddr_attr) != NULL) {
 214                 pattr->guardsize_attr = 0;
 215                 pattr->flags |= THR_STACK_USER;
 216                 ret = 0;
 217         }
 218         else
 219                 ret = _thr_stack_alloc(pattr);
 220         return (ret);
 221 }
 222
 223 static void
 224 thread_start(void *arg)
 225 {
 226         struct pthread *curthread = (struct pthread *)arg;
 227
 228         tls_set_tcb(curthread->tcb);
 229
 230         /* Thread was created with all signals blocked, unblock them. */
 231         __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
 232
 233         THR_LOCK(curthread);
 234         THR_UNLOCK(curthread);
 235
 236         if (curthread->flags & THR_FLAGS_NEED_SUSPEND)
 237                 _thr_suspend_check(curthread);
 238         _nmalloc_thr_init();
 239
 240         /* Run the current thread's start routine with argument: */
 241         _pthread_exit(curthread->start_routine(curthread->arg));
 242
 243         /* This point should never be reached. */
 244         PANIC("Thread has resumed after exit");
 245 }
 246
 247 __strong_reference(_pthread_create, pthread_create);