lib/libc_r/uthread/uthread_exit.c

   1 /*
   2  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by John Birrell.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/lib/libc_r/uthread/uthread_exit.c,v 1.16.2.8 2002/10/22 14:44:03 fjoe Exp $
  33  * $DragonFly: src/lib/libc_r/uthread/uthread_exit.c,v 1.6 2007/01/08 22:41:53 dillon Exp $
  34  */
  35 #include <errno.h>
  36 #include <unistd.h>
  37 #include <fcntl.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <pthread.h>
  42 #include "pthread_private.h"
  43
  44 #define FLAGS_IN_SCHEDQ \
  45         (PTHREAD_FLAGS_IN_PRIOQ|PTHREAD_FLAGS_IN_WAITQ|PTHREAD_FLAGS_IN_WORKQ)
  46
  47 void __exit(int status)
  48 {
  49         int             flags;
  50         int             i;
  51         struct itimerval itimer;
  52
  53         /* Disable the interval timer: */
  54         itimer.it_interval.tv_sec  = 0;
  55         itimer.it_interval.tv_usec = 0;
  56         itimer.it_value.tv_sec     = 0;
  57         itimer.it_value.tv_usec    = 0;
  58         setitimer(_ITIMER_SCHED_TIMER, &itimer, NULL);
  59
  60         /* Close the pthread kernel pipe: */
  61         __sys_close(_thread_kern_pipe[0]);
  62         __sys_close(_thread_kern_pipe[1]);
  63
  64         /*
  65          * Enter a loop to set all file descriptors to blocking
  66          * if they were not created as non-blocking:
  67          */
  68         for (i = 0; i < _thread_dtablesize; i++) {
  69                 /* Check if this file descriptor is in use: */
  70                 if (_thread_fd_table[i] != NULL &&
  71                     (_thread_fd_getflags(i) & O_NONBLOCK) == 0) {
  72                         /* Get the current flags: */
  73                         flags = __sys_fcntl(i, F_GETFL, NULL);
  74                         /* Clear the nonblocking file descriptor flag: */
  75                         __sys_fcntl(i, F_SETFL, flags & ~O_NONBLOCK);
  76                 }
  77         }
  78
  79         /* Call the _exit syscall: */
  80         __sys__exit(status);
  81 }
  82
  83 __strong_reference(__exit, _exit);
  84
  85 void
  86 _thread_exit(char *fname, int lineno, char *string)
  87 {
  88         char            s[256];
  89
  90         /* Prepare an error message string: */
  91         strcpy(s, "Fatal error '");
  92         strcat(s, string);
  93         strcat(s, "' at line ? ");
  94         strcat(s, "in file ");
  95         strcat(s, fname);
  96         strcat(s, " (errno = ?");
  97         strcat(s, ")\n");
  98
  99         /* Write the string to the standard error file descriptor: */
 100         /* XXX should this be non-blocking ? */
 101         __sys_extpwrite(2, s, strlen(s), O_FNONBLOCKING, -1);
 102
 103         /* Force this process to exit: */
 104         /* XXX - Do we want abort to be conditional on _PTHREADS_INVARIANTS? */
 105 #if defined(_PTHREADS_INVARIANTS)
 106         abort();
 107 #else
 108         _exit(1);
 109 #endif
 110 }
 111
 112 /*
 113  * Only called when a thread is cancelled.  It may be more useful
 114  * to call it from pthread_exit() if other ways of asynchronous or
 115  * abnormal thread termination can be found.
 116  */
 117 void
 118 _thread_exit_cleanup(void)
 119 {
 120         struct pthread  *curthread = _get_curthread();
 121
 122         /*
 123          * POSIX states that cancellation/termination of a thread should
 124          * not release any visible resources (such as mutexes) and that
 125          * it is the applications responsibility.  Resources that are
 126          * internal to the threads library, including file and fd locks,
 127          * are not visible to the application and need to be released.
 128          */
 129         /* Unlock all owned fd locks: */
 130         _thread_fd_unlock_owned(curthread);
 131
 132         /* Unlock all private mutexes: */
 133         _mutex_unlock_private(curthread);
 134
 135         /*
 136          * This still isn't quite correct because we don't account
 137          * for held spinlocks (see libc/stdlib/malloc.c).
 138          */
 139 }
 140
 141 void
 142 _pthread_exit(void *status)
 143 {
 144         struct pthread  *curthread = _get_curthread();
 145         pthread_t pthread;
 146
 147         /* Check if this thread is already in the process of exiting: */
 148         if ((curthread->flags & PTHREAD_EXITING) != 0) {
 149                 char msg[128];
 150                 snprintf(msg, sizeof(msg), "Thread %p has called pthread_exit() from a destructor. POSIX 1003.1 1996 s16.2.5.2 does not allow this!",curthread);
 151                 PANIC(msg);
 152         }
 153
 154         /* Flag this thread as exiting: */
 155         curthread->flags |= PTHREAD_EXITING;
 156
 157         /* Save the return value: */
 158         curthread->ret = status;
 159
 160         while (curthread->cleanup != NULL) {
 161                 pthread_cleanup_pop(1);
 162         }
 163         if (curthread->attr.cleanup_attr != NULL) {
 164                 curthread->attr.cleanup_attr(curthread->attr.arg_attr);
 165         }
 166         /* Check if there is thread specific data: */
 167         if (curthread->specific_data != NULL) {
 168                 /* Run the thread-specific data destructors: */
 169                 _thread_cleanupspecific();
 170         }
 171
 172         /* Free thread-specific poll_data structure, if allocated: */
 173         if (curthread->poll_data.fds != NULL) {
 174                 free(curthread->poll_data.fds);
 175                 curthread->poll_data.fds = NULL;
 176         }
 177
 178         /*
 179          * Lock the garbage collector mutex to ensure that the garbage
 180          * collector is not using the dead thread list.
 181          */
 182         if (pthread_mutex_lock(&_gc_mutex) != 0)
 183                 PANIC("Cannot lock gc mutex");
 184
 185         /* Add this thread to the list of dead threads. */
 186         TAILQ_INSERT_HEAD(&_dead_list, curthread, dle);
 187
 188         /*
 189          * Signal the garbage collector thread that there is something
 190          * to clean up.
 191          */
 192         if (pthread_cond_signal(&_gc_cond) != 0)
 193                 PANIC("Cannot signal gc cond");
 194
 195         /*
 196          * Avoid a race condition where a scheduling signal can occur
 197          * causing the garbage collector thread to run.  If this happens,
 198          * the current thread can be cleaned out from under us.
 199          */
 200         _thread_kern_sig_defer();
 201
 202         /* Unlock the garbage collector mutex: */
 203         if (pthread_mutex_unlock(&_gc_mutex) != 0)
 204                 PANIC("Cannot unlock gc mutex");
 205
 206         /* Check if there is a thread joining this one: */
 207         if (curthread->joiner != NULL) {
 208                 pthread = curthread->joiner;
 209                 curthread->joiner = NULL;
 210
 211                 /* Make the joining thread runnable: */
 212                 PTHREAD_NEW_STATE(pthread, PS_RUNNING);
 213
 214                 /* Set the return value for the joining thread: */
 215                 pthread->join_status.ret = curthread->ret;
 216                 pthread->join_status.error = 0;
 217                 pthread->join_status.thread = NULL;
 218
 219                 /* Make this thread collectable by the garbage collector. */
 220                 PTHREAD_ASSERT(((curthread->attr.flags & PTHREAD_DETACHED) ==
 221                     0), "Cannot join a detached thread");
 222                 curthread->attr.flags |= PTHREAD_DETACHED;
 223         }
 224
 225         /* Remove this thread from the thread list: */
 226         TAILQ_REMOVE(&_thread_list, curthread, tle);
 227
 228         /* This thread will never be re-scheduled. */
 229         _thread_kern_sched_state(PS_DEAD, __FILE__, __LINE__);
 230
 231         /* This point should not be reached. */
 232         PANIC("Dead thread has resumed");
 233 }
 234
 235 __strong_reference(_pthread_exit, pthread_exit);