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 1.5 2005/10/10 13:45:57 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 <machine/tls.h>
  46
  47 #include <pthread.h>
  48 #include <sys/signalvar.h>
  49
  50 #include "thr_private.h"
  51 #include "libc_private.h"
  52
  53 struct start_arg {
  54         struct pthread  *thread;
  55         volatile umtx_t started;
  56 };
  57
  58 static void free_thread(struct pthread *curthread, struct pthread *thread);
  59 static int  create_stack(struct pthread_attr *pattr);
  60 static void free_stack(struct pthread *curthread, struct pthread_attr *pattr);
  61 static void thread_start(void *);
  62
  63 __weak_reference(_pthread_create, pthread_create);
  64
  65 int
  66 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
  67                void *(*start_routine) (void *), void *arg)
  68 {
  69         struct start_arg start_arg;
  70         void *stack;
  71         sigset_t sigmask, oldsigmask;
  72         struct pthread *curthread, *new_thread;
  73         int ret = 0, locked;
  74
  75         _thr_check_init();
  76
  77         /*
  78          * Tell libc and others now they need lock to protect their data.
  79          */
  80         if (_thr_isthreaded() == 0 && _thr_setthreaded(1))
  81                 return (EAGAIN);
  82
  83         curthread = tls_get_curthread();
  84         if ((new_thread = _thr_alloc(curthread)) == NULL)
  85                 return (EAGAIN);
  86
  87         if (attr == NULL || *attr == NULL)
  88                 /* Use the default thread attributes: */
  89                 new_thread->attr = _pthread_attr_default;
  90         else
  91                 new_thread->attr = *(*attr);
  92         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  93                 /* inherit scheduling contention scope */
  94                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  95                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
  96                 else
  97                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
  98                 /*
  99                  * scheduling policy and scheduling parameters will be
 100                  * inherited in following code.
 101                  */
 102         }
 103
 104         if (_thread_scope_system > 0)
 105                 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
 106         else if (_thread_scope_system < 0)
 107                 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
 108
 109         if (create_stack(&new_thread->attr) != 0) {
 110                 /* Insufficient memory to create a stack: */
 111                 new_thread->terminated = 1;
 112                 _thr_free(curthread, new_thread);
 113                 return (EAGAIN);
 114         }
 115         /*
 116          * Write a magic value to the thread structure
 117          * to help identify valid ones:
 118          */
 119         new_thread->magic = THR_MAGIC;
 120         new_thread->start_routine = start_routine;
 121         new_thread->arg = arg;
 122         new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
 123             PTHREAD_CANCEL_DEFERRED;
 124         /*
 125          * Check if this thread is to inherit the scheduling
 126          * attributes from its parent:
 127          */
 128         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
 129                 /*
 130                  * Copy the scheduling attributes. Lock the scheduling
 131                  * lock to get consistent scheduling parameters.
 132                  */
 133                 THR_LOCK(curthread);
 134                 new_thread->base_priority = curthread->base_priority;
 135                 new_thread->attr.prio = curthread->base_priority;
 136                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
 137                 THR_UNLOCK(curthread);
 138         } else {
 139                 /*
 140                  * Use just the thread priority, leaving the
 141                  * other scheduling attributes as their
 142                  * default values:
 143                  */
 144                 new_thread->base_priority = new_thread->attr.prio;
 145         }
 146         new_thread->active_priority = new_thread->base_priority;
 147
 148         /* Initialize the mutex queue: */
 149         TAILQ_INIT(&new_thread->mutexq);
 150         TAILQ_INIT(&new_thread->pri_mutexq);
 151
 152         /* Initialise hooks in the thread structure: */
 153         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED)
 154                 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
 155         new_thread->state = PS_RUNNING;
 156         /*
 157          * Thread created by thr_create() inherits currrent thread
 158          * sigmask, however, before new thread setup itself correctly,
 159          * it can not handle signal, so we should masks all signals here.
 160          */
 161         SIGFILLSET(sigmask);
 162         __sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask);
 163         new_thread->sigmask = oldsigmask;
 164         /* Add the new thread. */
 165         _thr_link(curthread, new_thread);
 166         /* Return thread pointer eariler so that new thread can use it. */
 167         (*thread) = new_thread;
 168         if (SHOULD_REPORT_EVENT(curthread, TD_CREATE)) {
 169                 THR_THREAD_LOCK(curthread, new_thread);
 170                 locked = 1;
 171         } else
 172                 locked = 0;
 173         /* Schedule the new thread. */
 174         stack = (char *)new_thread->attr.stackaddr_attr +
 175                         new_thread->attr.stacksize_attr;
 176         start_arg.thread  = new_thread;
 177         start_arg.started = 0;
 178         ret = rfork_thread(RFPROC | RFNOWAIT | RFMEM | RFSIGSHARE, stack,
 179                            (int (*)(void *))thread_start, &start_arg);
 180         __sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL);
 181         if (ret >= 0) {
 182                 /*
 183                  * Wait until new thread get its thread id, so we can
 184                  * send signal to it immediately after we return.
 185                  */
 186                 while (start_arg.started == 0)
 187                         _thr_umtx_wait(&start_arg.started, 0, NULL, 0);
 188                 ret = 0;
 189         } else {
 190                 ret = EAGAIN;
 191         }
 192         if (ret != 0) {
 193                 if (locked)
 194                         THR_THREAD_UNLOCK(curthread, new_thread);
 195                 _thr_unlink(curthread, new_thread);
 196                 free_thread(curthread, new_thread);
 197                 (*thread) = 0;
 198                 ret = EAGAIN;
 199         } else if (locked) {
 200                 _thr_report_creation(curthread, new_thread);
 201                 THR_THREAD_UNLOCK(curthread, new_thread);
 202         }
 203         return (ret);
 204 }
 205
 206 static void
 207 free_thread(struct pthread *curthread, struct pthread *thread)
 208 {
 209         free_stack(curthread, &thread->attr);
 210         curthread->terminated = 1;
 211         _thr_free(curthread, thread);
 212 }
 213
 214 static int
 215 create_stack(struct pthread_attr *pattr)
 216 {
 217         int ret;
 218
 219         /* Check if a stack was specified in the thread attributes: */
 220         if ((pattr->stackaddr_attr) != NULL) {
 221                 pattr->guardsize_attr = 0;
 222                 pattr->flags |= THR_STACK_USER;
 223                 ret = 0;
 224         }
 225         else
 226                 ret = _thr_stack_alloc(pattr);
 227         return (ret);
 228 }
 229
 230 static void
 231 free_stack(struct pthread *curthread, struct pthread_attr *pattr)
 232 {
 233         if ((pattr->flags & THR_STACK_USER) == 0) {
 234                 THREAD_LIST_LOCK(curthread);
 235                 /* Stack routines don't use malloc/free. */
 236                 _thr_stack_free(pattr);
 237                 THREAD_LIST_UNLOCK(curthread);
 238         }
 239 }
 240
 241 static void
 242 thread_start(void *arg)
 243 {
 244         struct pthread *curthread;
 245         struct start_arg *start_arg = arg;
 246
 247         curthread = start_arg->thread;
 248         curthread->tid = _thr_get_tid();
 249         tls_set_tcb(curthread->tcb);
 250         start_arg->started = 1;
 251         _thr_umtx_wake(&start_arg->started, 1);
 252
 253         THR_LOCK(curthread);
 254         THR_UNLOCK(curthread);
 255
 256         /* Thread was created with all signals blocked, unblock them. */
 257         __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
 258
 259         if (curthread->flags & THR_FLAGS_NEED_SUSPEND)
 260                 _thr_suspend_check(curthread);
 261
 262         /* Run the current thread's start routine with argument: */
 263         pthread_exit(curthread->start_routine(curthread->arg));
 264
 265         /* This point should never be reached. */
 266         PANIC("Thread has resumed after exit");
 267 }