lib/libpthread/thread/thr_suspend_np.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  * $FreeBSD$
  33  */
  34 #include <errno.h>
  35 #ifdef _THREAD_SAFE
  36 #include <pthread.h>
  37 #include "pthread_private.h"
  38
  39 static void     finish_suspension(void *arg);
  40
  41 /* Suspend a thread: */
  42 int
  43 pthread_suspend_np(pthread_t thread)
  44 {
  45         int ret;
  46
  47         /* Find the thread in the list of active threads: */
  48         if ((ret = _find_thread(thread)) == 0) {
  49                 /*
  50                  * Defer signals to protect the scheduling queues from
  51                  * access by the signal handler:
  52                  */
  53                 _thread_kern_sig_defer();
  54
  55                 switch (thread->state) {
  56                 case PS_RUNNING:
  57                         /*
  58                          * Remove the thread from the priority queue and
  59                          * set the state to suspended:
  60                          */
  61                         PTHREAD_PRIOQ_REMOVE(thread);
  62                         PTHREAD_SET_STATE(thread, PS_SUSPENDED);
  63                         break;
  64
  65                 case PS_SPINBLOCK:
  66                 case PS_FDR_WAIT:
  67                 case PS_FDW_WAIT:
  68                 case PS_POLL_WAIT:
  69                 case PS_SELECT_WAIT:
  70                         /*
  71                          * Remove these threads from the work queue
  72                          * and mark the operation as interrupted:
  73                          */
  74                         if ((thread->flags & PTHREAD_FLAGS_IN_WORKQ) != 0)
  75                                 PTHREAD_WORKQ_REMOVE(thread);
  76                         _thread_seterrno(thread,EINTR);
  77                         thread->interrupted = 1;
  78
  79                         /* FALLTHROUGH */
  80                 case PS_SIGTHREAD:
  81                 case PS_SLEEP_WAIT:
  82                 case PS_WAIT_WAIT:
  83                 case PS_SIGSUSPEND:
  84                 case PS_SIGWAIT:
  85                         /*
  86                          * Remove these threads from the waiting queue and
  87                          * set their state to suspended:
  88                          */
  89                         PTHREAD_WAITQ_REMOVE(thread);
  90                         PTHREAD_SET_STATE(thread, PS_SUSPENDED);
  91                         break;
  92
  93                 case PS_MUTEX_WAIT:
  94                 case PS_COND_WAIT:
  95                 case PS_FDLR_WAIT:
  96                 case PS_FDLW_WAIT:
  97                 case PS_FILE_WAIT:
  98                 case PS_JOIN:
  99                         /* Mark the thread as suspended: */
 100                         thread->suspended = 1;
 101
 102                         /*
 103                          * Threads in these states may be in queues.
 104                          * In order to preserve queue integrity, the
 105                          * cancelled thread must remove itself from the
 106                          * queue.  Mark the thread as interrupted and
 107                          * set the state to running.  When the thread
 108                          * resumes, it will remove itself from the queue
 109                          * and call the suspension completion routine.
 110                          */
 111                         thread->interrupted = 1;
 112                         _thread_seterrno(thread, EINTR);
 113                         PTHREAD_NEW_STATE(thread, PS_RUNNING);
 114                         thread->continuation = finish_suspension;
 115                         break;
 116
 117                 case PS_DEAD:
 118                 case PS_DEADLOCK:
 119                 case PS_STATE_MAX:
 120                 case PS_SUSPENDED:
 121                         /* Nothing needs to be done: */
 122                         break;
 123                 }
 124
 125                 /*
 126                  * Undefer and handle pending signals, yielding if
 127                  * necessary:
 128                  */
 129                 _thread_kern_sig_undefer();
 130         }
 131         return(ret);
 132 }
 133
 134 static void
 135 finish_suspension(void *arg)
 136 {
 137         if (_thread_run->suspended != 0)
 138                 _thread_kern_sched_state(PS_SUSPENDED, __FILE__, __LINE__);
 139 }
 140
 141
 142 #endif