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 1.2 2005/03/15 11:24:23 davidxu Exp $
  36  */
  37 #include <errno.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <fcntl.h>
  41 #include <unistd.h>
  42 #include <stddef.h>
  43 #include <sys/time.h>
  44 #include <machine/reg.h>
  45 #include <pthread.h>
  46 #include <sys/signalvar.h>
  47
  48 #include "thr_private.h"
  49 #include "libc_private.h"
  50
  51 struct start_arg {
  52         struct pthread  *thread;
  53         volatile umtx_t started;
  54 };
  55
  56 static void free_thread(struct pthread *curthread, struct pthread *thread);
  57 static int  create_stack(struct pthread_attr *pattr);
  58 static void free_stack(struct pthread *curthread, struct pthread_attr *pattr);
  59 static void thread_start(void *);
  60
  61 __weak_reference(_pthread_create, pthread_create);
  62
  63 int
  64 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
  65                void *(*start_routine) (void *), void *arg)
  66 {
  67         struct start_arg start_arg;
  68         void *stack;
  69         sigset_t sigmask, oldsigmask;
  70         struct pthread *curthread, *new_thread;
  71         int ret = 0;
  72
  73         _thr_check_init();
  74
  75         /*
  76          * Tell libc and others now they need lock to protect their data.
  77          */
  78         if (_thr_isthreaded() == 0 && _thr_setthreaded(1))
  79                 return (EAGAIN);
  80
  81         curthread = _get_curthread();
  82         if ((new_thread = _thr_alloc(curthread)) == NULL)
  83                 return (EAGAIN);
  84
  85         if (attr == NULL || *attr == NULL)
  86                 /* Use the default thread attributes: */
  87                 new_thread->attr = _pthread_attr_default;
  88         else
  89                 new_thread->attr = *(*attr);
  90         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  91                 /* inherit scheduling contention scope */
  92                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  93                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  94                 else
  95                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
  96                 /*
  97                  * scheduling policy and scheduling parameters will be
  98                  * inherited in following code.
  99                  */
 100         }
 101
 102         if (_thread_scope_system > 0)
 103                 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
 104         else if (_thread_scope_system < 0)
 105                 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
 106
 107         if (create_stack(&new_thread->attr) != 0) {
 108                 /* Insufficient memory to create a stack: */
 109                 new_thread->terminated = 1;
 110                 _thr_free(curthread, new_thread);
 111                 return (EAGAIN);
 112         }
 113         /*
 114          * Write a magic value to the thread structure
 115          * to help identify valid ones:
 116          */
 117         new_thread->magic = THR_MAGIC;
 118         new_thread->start_routine = start_routine;
 119         new_thread->arg = arg;
 120         new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
 121             PTHREAD_CANCEL_DEFERRED;
 122         /*
 123          * Check if this thread is to inherit the scheduling
 124          * attributes from its parent:
 125          */
 126         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
 127                 /*
 128                  * Copy the scheduling attributes. Lock the scheduling
 129                  * lock to get consistent scheduling parameters.
 130                  */
 131                 THR_LOCK(curthread);
 132                 new_thread->base_priority = curthread->base_priority;
 133                 new_thread->attr.prio = curthread->base_priority;
 134                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
 135                 THR_UNLOCK(curthread);
 136         } else {
 137                 /*
 138                  * Use just the thread priority, leaving the
 139                  * other scheduling attributes as their
 140                  * default values:
 141                  */
 142                 new_thread->base_priority = new_thread->attr.prio;
 143         }
 144         new_thread->active_priority = new_thread->base_priority;
 145
 146         /* Initialize the mutex queue: */
 147         TAILQ_INIT(&new_thread->mutexq);
 148         TAILQ_INIT(&new_thread->pri_mutexq);
 149
 150         /* Initialise hooks in the thread structure: */
 151         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED)
 152                 new_thread->flags = THR_FLAGS_SUSPENDED;
 153         new_thread->state = PS_RUNNING;
 154         /*
 155          * Thread created by thr_create() inherits currrent thread
 156          * sigmask, however, before new thread setup itself correctly,
 157          * it can not handle signal, so we should masks all signals here.
 158          */
 159         SIGFILLSET(sigmask);
 160         __sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask);
 161         new_thread->sigmask = oldsigmask;
 162         /* Add the new thread. */
 163         _thr_link(curthread, new_thread);
 164         /* Return thread pointer eariler so that new thread can use it. */
 165         (*thread) = new_thread;
 166         /* Schedule the new thread. */
 167         stack = (char *)new_thread->attr.stackaddr_attr +
 168                         new_thread->attr.stacksize_attr;
 169         start_arg.thread  = new_thread;
 170         start_arg.started = 0;
 171         ret = rfork_thread(RFPROC | RFNOWAIT | RFMEM | RFSIGSHARE, stack,
 172                            (int (*)(void *))thread_start, &start_arg);
 173         __sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL);
 174         if (ret >= 0) {
 175                 /*
 176                  * Wait until new thread get its thread id, so we can
 177                  * send signal to it immediately after we return.
 178                  */
 179                 while (start_arg.started == 0)
 180                         _thr_umtx_wait(&start_arg.started, 0, NULL, 0);
 181                 ret = 0;
 182         } else {
 183                 ret = EAGAIN;
 184         }
 185         if (ret != 0) {
 186                 _thr_unlink(curthread, new_thread);
 187                 free_thread(curthread, new_thread);
 188                 (*thread) = 0;
 189                 ret = EAGAIN;
 190         }
 191         return (ret);
 192 }
 193
 194 static void
 195 free_thread(struct pthread *curthread, struct pthread *thread)
 196 {
 197         free_stack(curthread, &thread->attr);
 198         curthread->terminated = 1;
 199         _thr_free(curthread, thread);
 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 free_stack(struct pthread *curthread, struct pthread_attr *pattr)
 220 {
 221         if ((pattr->flags & THR_STACK_USER) == 0) {
 222                 THREAD_LIST_LOCK(curthread);
 223                 /* Stack routines don't use malloc/free. */
 224                 _thr_stack_free(pattr);
 225                 THREAD_LIST_UNLOCK(curthread);
 226         }
 227 }
 228
 229 static void
 230 thread_start(void *arg)
 231 {
 232         struct pthread *curthread;
 233         struct start_arg *start_arg = arg;
 234
 235         curthread = start_arg->thread;
 236         curthread->tid = _thr_get_tid();
 237         _tcb_set(curthread->tcb);
 238         start_arg->started = 1;
 239         _thr_umtx_wake(&start_arg->started, 1);
 240
 241         /* Thread was created with all signals blocked, unblock them. */
 242         __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
 243
 244         if (curthread->flags & THR_FLAGS_NEED_SUSPEND)
 245                 _thr_suspend_check(curthread);
 246
 247         /* Run the current thread's start routine with argument: */
 248         pthread_exit(curthread->start_routine(curthread->arg));
 249
 250         /* This point should never be reached. */
 251         PANIC("Thread has resumed after exit");
 252 }