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  * 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, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/lib/libpthread/thread/thr_create.c,v 1.58 2004/10/23 23:28:36 davidxu Exp $
  27  */
  28
  29 #include "namespace.h"
  30 #include <errno.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <fcntl.h>
  34 #include <unistd.h>
  35 #include <stddef.h>
  36 #include <sys/time.h>
  37 #include <machine/reg.h>
  38 #include <machine/tls.h>
  39 #include <pthread.h>
  40 #include <sys/signalvar.h>
  41 #include "un-namespace.h"
  42
  43 #include "thr_private.h"
  44 #include "libc_private.h"
  45
  46 static int  create_stack(struct pthread_attr *pattr);
  47 static void thread_start(void *);
  48
  49 int
  50 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
  51     void *(*start_routine) (void *), void *arg)
  52 {
  53         struct lwp_params create_params;
  54         void *stack;
  55         sigset_t sigmask, oldsigmask;
  56         struct pthread *curthread, *new_thread;
  57         int ret = 0, locked;
  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 = tls_get_curthread();
  68         if ((new_thread = _thr_alloc(curthread)) == NULL)
  69                 return (EAGAIN);
  70
  71         if (attr == NULL || *attr == NULL)
  72                 /* Use the default thread attributes: */
  73                 new_thread->attr = _pthread_attr_default;
  74         else
  75                 new_thread->attr = *(*attr);
  76         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  77                 /* inherit scheduling contention scope */
  78                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  79                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  80                 else
  81                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
  82                 /*
  83                  * scheduling policy and scheduling parameters will be
  84                  * inherited in following code.
  85                  */
  86         }
  87
  88         if (_thread_scope_system > 0)
  89                 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  90         else if (_thread_scope_system < 0)
  91                 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
  92
  93         if (create_stack(&new_thread->attr) != 0) {
  94                 /* Insufficient memory to create a stack: */
  95                 new_thread->terminated = 1;
  96                 _thr_free(curthread, new_thread);
  97                 return (EAGAIN);
  98         }
  99         /*
 100          * Write a magic value to the thread structure
 101          * to help identify valid ones:
 102          */
 103         new_thread->magic = THR_MAGIC;
 104         new_thread->start_routine = start_routine;
 105         new_thread->arg = arg;
 106         new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
 107             PTHREAD_CANCEL_DEFERRED;
 108         /*
 109          * Check if this thread is to inherit the scheduling
 110          * attributes from its parent:
 111          */
 112         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
 113                 /*
 114                  * Copy the scheduling attributes. Lock the scheduling
 115                  * lock to get consistent scheduling parameters.
 116                  */
 117                 THR_LOCK(curthread);
 118                 new_thread->base_priority = curthread->base_priority;
 119                 new_thread->attr.prio = curthread->attr.prio;
 120                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
 121                 THR_UNLOCK(curthread);
 122         } else {
 123                 /*
 124                  * Use just the thread priority, leaving the
 125                  * other scheduling attributes as their
 126                  * default values:
 127                  */
 128                 new_thread->base_priority = new_thread->attr.prio;
 129         }
 130         new_thread->active_priority = new_thread->base_priority;
 131
 132         /* Initialize the mutex queue: */
 133         TAILQ_INIT(&new_thread->mutexq);
 134
 135         /* Initialise hooks in the thread structure: */
 136         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED)
 137                 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
 138
 139         new_thread->state = PS_RUNNING;
 140
 141         if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
 142                 new_thread->tlflags |= TLFLAGS_DETACHED;
 143
 144         /* Add the new thread. */
 145         new_thread->refcount = 1;
 146         _thr_link(curthread, new_thread);
 147         /* Return thread pointer eariler so that new thread can use it. */
 148         (*thread) = new_thread;
 149         if (SHOULD_REPORT_EVENT(curthread, TD_CREATE)) {
 150                 THR_THREAD_LOCK(curthread, new_thread);
 151                 locked = 1;
 152         } else
 153                 locked = 0;
 154         /* Schedule the new thread. */
 155         stack = (char *)new_thread->attr.stackaddr_attr +
 156                         new_thread->attr.stacksize_attr;
 157         bzero(&create_params, sizeof(create_params));
 158         create_params.lwp_func = thread_start;
 159         create_params.lwp_arg = new_thread;
 160         create_params.lwp_stack = stack;
 161         create_params.lwp_tid1 = &new_thread->tid;
 162         /*
 163          * Thread created by thr_create() inherits currrent thread
 164          * sigmask, however, before new thread setup itself correctly,
 165          * it can not handle signal, so we should mask all signals here.
 166          * We do this at the very last moment, so that we don't run
 167          * into problems while we have all signals disabled.
 168          */
 169         SIGFILLSET(sigmask);
 170         __sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask);
 171         new_thread->sigmask = oldsigmask;
 172         ret = lwp_create(&create_params);
 173         __sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL);
 174         if (ret != 0) {
 175                 if (!locked)
 176                         THR_THREAD_LOCK(curthread, new_thread);
 177                 new_thread->state = PS_DEAD;
 178                 new_thread->terminated = 1;
 179                 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
 180                         new_thread->cycle++;
 181                         _thr_umtx_wake(&new_thread->cycle, INT_MAX);
 182                 }
 183                 THR_THREAD_UNLOCK(curthread, new_thread);
 184                 THREAD_LIST_LOCK(curthread);
 185                 _thread_active_threads--;
 186                 new_thread->tlflags |= TLFLAGS_DETACHED;
 187                 _thr_ref_delete_unlocked(curthread, new_thread);
 188                 THREAD_LIST_UNLOCK(curthread);
 189                 (*thread) = NULL;
 190                 ret = EAGAIN;
 191         } else if (locked) {
 192                 _thr_report_creation(curthread, new_thread);
 193                 THR_THREAD_UNLOCK(curthread, new_thread);
 194         }
 195         return (ret);
 196 }
 197
 198 static int
 199 create_stack(struct pthread_attr *pattr)
 200 {
 201         int ret;
 202
 203         /* Check if a stack was specified in the thread attributes: */
 204         if ((pattr->stackaddr_attr) != NULL) {
 205                 pattr->guardsize_attr = 0;
 206                 pattr->flags |= THR_STACK_USER;
 207                 ret = 0;
 208         }
 209         else
 210                 ret = _thr_stack_alloc(pattr);
 211         return (ret);
 212 }
 213
 214 static void
 215 thread_start(void *arg)
 216 {
 217         struct pthread *curthread = (struct pthread *)arg;
 218
 219         tls_set_tcb(curthread->tcb);
 220
 221         /* Thread was created with all signals blocked, unblock them. */
 222         __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
 223
 224         THR_LOCK(curthread);
 225         THR_UNLOCK(curthread);
 226
 227         if (curthread->flags & THR_FLAGS_NEED_SUSPEND)
 228                 _thr_suspend_check(curthread);
 229         _nmalloc_thr_init();
 230
 231         /* Run the current thread's start routine with argument: */
 232         _pthread_exit(curthread->start_routine(curthread->arg));
 233
 234         /* This point should never be reached. */
 235         PANIC("Thread has resumed after exit");
 236 }
 237
 238 __strong_reference(_pthread_create, pthread_create);