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  * $DragonFly: src/lib/libthread_xu/thread/thr_create.c,v 1.10 2006/04/06 13:03:09 davidxu Exp $
  36  */
  37
  38 #include "namespace.h"
  39 #include <errno.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <fcntl.h>
  43 #include <unistd.h>
  44 #include <stddef.h>
  45 #include <sys/time.h>
  46 #include <machine/reg.h>
  47 #include <machine/tls.h>
  48
  49 #include <pthread.h>
  50 #include <sys/signalvar.h>
  51 #include "un-namespace.h"
  52
  53 #include "thr_private.h"
  54 #include "libc_private.h"
  55
  56 struct start_arg {
  57         struct pthread  *thread;
  58         volatile umtx_t started;
  59 };
  60
  61 static int  create_stack(struct pthread_attr *pattr);
  62 static void thread_start(void *);
  63
  64 int
  65 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
  66        void *(*start_routine) (void *), void *arg)
  67 {
  68         struct start_arg start_arg;
  69         void *stack;
  70         sigset_t sigmask, oldsigmask;
  71         struct pthread *curthread, *new_thread;
  72         int ret = 0, locked;
  73
  74         _thr_check_init();
  75
  76         /*
  77          * Tell libc and others now they need lock to protect their data.
  78          */
  79         if (_thr_isthreaded() == 0 && _thr_setthreaded(1))
  80                 return (EAGAIN);
  81
  82         curthread = tls_get_curthread();
  83         if ((new_thread = _thr_alloc(curthread)) == NULL)
  84                 return (EAGAIN);
  85
  86         if (attr == NULL || *attr == NULL)
  87                 /* Use the default thread attributes: */
  88                 new_thread->attr = _pthread_attr_default;
  89         else
  90                 new_thread->attr = *(*attr);
  91         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  92                 /* inherit scheduling contention scope */
  93                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  94                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  95                 else
  96                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
  97                 /*
  98                  * scheduling policy and scheduling parameters will be
  99                  * inherited in following code.
 100                  */
 101         }
 102
 103         if (_thread_scope_system > 0)
 104                 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
 105         else if (_thread_scope_system < 0)
 106                 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
 107
 108         if (create_stack(&new_thread->attr) != 0) {
 109                 /* Insufficient memory to create a stack: */
 110                 new_thread->terminated = 1;
 111                 _thr_free(curthread, new_thread);
 112                 return (EAGAIN);
 113         }
 114         /*
 115          * Write a magic value to the thread structure
 116          * to help identify valid ones:
 117          */
 118         new_thread->magic = THR_MAGIC;
 119         new_thread->start_routine = start_routine;
 120         new_thread->arg = arg;
 121         new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
 122             PTHREAD_CANCEL_DEFERRED;
 123         /*
 124          * Check if this thread is to inherit the scheduling
 125          * attributes from its parent:
 126          */
 127         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
 128                 /*
 129                  * Copy the scheduling attributes. Lock the scheduling
 130                  * lock to get consistent scheduling parameters.
 131                  */
 132                 THR_LOCK(curthread);
 133                 new_thread->base_priority = curthread->base_priority;
 134                 new_thread->attr.prio = curthread->base_priority;
 135                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
 136                 THR_UNLOCK(curthread);
 137         } else {
 138                 /*
 139                  * Use just the thread priority, leaving the
 140                  * other scheduling attributes as their
 141                  * default values:
 142                  */
 143                 new_thread->base_priority = new_thread->attr.prio;
 144         }
 145         new_thread->active_priority = new_thread->base_priority;
 146
 147         /* Initialize the mutex queue: */
 148         TAILQ_INIT(&new_thread->mutexq);
 149
 150         /* Initialise hooks in the thread structure: */
 151         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED)
 152                 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
 153
 154         new_thread->state = PS_RUNNING;
 155
 156         if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
 157                 new_thread->tlflags |= TLFLAGS_DETACHED;
 158
 159         /*
 160          * Thread created by thr_create() inherits currrent thread
 161          * sigmask, however, before new thread setup itself correctly,
 162          * it can not handle signal, so we should masks all signals here.
 163          */
 164         SIGFILLSET(sigmask);
 165         __sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask);
 166         new_thread->sigmask = oldsigmask;
 167         /* Add the new thread. */
 168         new_thread->refcount = 1;
 169         _thr_link(curthread, new_thread);
 170         /* Return thread pointer eariler so that new thread can use it. */
 171         (*thread) = new_thread;
 172         if (SHOULD_REPORT_EVENT(curthread, TD_CREATE)) {
 173                 THR_THREAD_LOCK(curthread, new_thread);
 174                 locked = 1;
 175         } else
 176                 locked = 0;
 177         /* Schedule the new thread. */
 178         stack = (char *)new_thread->attr.stackaddr_attr +
 179                         new_thread->attr.stacksize_attr;
 180         start_arg.thread  = new_thread;
 181         start_arg.started = 0;
 182         ret = rfork_thread(RFPROC | RFNOWAIT | RFMEM | RFSIGSHARE, stack,
 183                            (int (*)(void *))thread_start, &start_arg);
 184         __sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL);
 185         if (ret >= 0) {
 186                 /*
 187                  * Wait until new thread get its thread id, so we can
 188                  * send signal to it immediately after we return.
 189                  */
 190                 while (start_arg.started == 0)
 191                         _thr_umtx_wait(&start_arg.started, 0, NULL, 0);
 192                 ret = 0;
 193         } else {
 194                 ret = EAGAIN;
 195         }
 196         if (ret != 0) {
 197                 if (!locked)
 198                         THR_THREAD_LOCK(curthread, new_thread);
 199                 new_thread->state = PS_DEAD;
 200                 new_thread->terminated = 1;
 201                 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
 202                         new_thread->cycle++;
 203                         _thr_umtx_wake(&new_thread->cycle, INT_MAX);
 204                 }
 205                 THR_THREAD_UNLOCK(curthread, new_thread);
 206                 THREAD_LIST_LOCK(curthread);
 207                 _thread_active_threads--;
 208                 new_thread->tlflags |= TLFLAGS_DETACHED;
 209                 _thr_ref_delete_unlocked(curthread, new_thread);
 210                 THREAD_LIST_UNLOCK(curthread);
 211                 (*thread) = 0;
 212                 ret = EAGAIN;
 213         } else if (locked) {
 214                 _thr_report_creation(curthread, new_thread);
 215                 THR_THREAD_UNLOCK(curthread, new_thread);
 216         }
 217         return (ret);
 218 }
 219
 220 static int
 221 create_stack(struct pthread_attr *pattr)
 222 {
 223         int ret;
 224
 225         /* Check if a stack was specified in the thread attributes: */
 226         if ((pattr->stackaddr_attr) != NULL) {
 227                 pattr->guardsize_attr = 0;
 228                 pattr->flags |= THR_STACK_USER;
 229                 ret = 0;
 230         }
 231         else
 232                 ret = _thr_stack_alloc(pattr);
 233         return (ret);
 234 }
 235
 236 static void
 237 thread_start(void *arg)
 238 {
 239         struct pthread *curthread;
 240         struct start_arg *start_arg = arg;
 241
 242         curthread = start_arg->thread;
 243         curthread->tid = _thr_get_tid();
 244         tls_set_tcb(curthread->tcb);
 245         start_arg->started = 1;
 246         _thr_umtx_wake(&start_arg->started, 1);
 247
 248         /* Thread was created with all signals blocked, unblock them. */
 249         __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
 250
 251         THR_LOCK(curthread);
 252         THR_UNLOCK(curthread);
 253
 254         if (curthread->flags & THR_FLAGS_NEED_SUSPEND)
 255                 _thr_suspend_check(curthread);
 256
 257         /* Run the current thread's start routine with argument: */
 258         _pthread_exit(curthread->start_routine(curthread->arg));
 259
 260         /* This point should never be reached. */
 261         PANIC("Thread has resumed after exit");
 262 }
 263
 264 __strong_reference(_pthread_create, pthread_create);