mirror of git://sourceware.org/git/glibc.git
				
				
				
			
		
			
				
	
	
		
			134 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			134 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
| /* Suspend until termination of a requests.
 | |
|    Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
 | |
|    This file is part of the GNU C Library.
 | |
|    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 | |
| 
 | |
|    The GNU C Library is free software; you can redistribute it and/or
 | |
|    modify it under the terms of the GNU Library General Public License as
 | |
|    published by the Free Software Foundation; either version 2 of the
 | |
|    License, or (at your option) any later version.
 | |
| 
 | |
|    The GNU C Library is distributed in the hope that it will be useful,
 | |
|    but WITHOUT ANY WARRANTY; without even the implied warranty of
 | |
|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 | |
|    Library General Public License for more details.
 | |
| 
 | |
|    You should have received a copy of the GNU Library General Public
 | |
|    License along with the GNU C Library; see the file COPYING.LIB.  If not,
 | |
|    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 | |
|    Boston, MA 02111-1307, USA.  */
 | |
| 
 | |
| 
 | |
| /* We use an UGLY hack to prevent gcc from finding us cheating.  The
 | |
|    implementation of aio_suspend and aio_suspend64 are identical and so
 | |
|    we want to avoid code duplication by using aliases.  But gcc sees
 | |
|    the different parameter lists and prints a warning.  We define here
 | |
|    a function so that aio_suspend64 has no prototype.  */
 | |
| #define aio_suspend64 XXX
 | |
| #include <aio.h>
 | |
| /* And undo the hack.  */
 | |
| #undef aio_suspend64
 | |
| 
 | |
| #include <errno.h>
 | |
| 
 | |
| #include "aio_misc.h"
 | |
| 
 | |
| 
 | |
| int
 | |
| aio_suspend (list, nent, timeout)
 | |
|      const struct aiocb *const list[];
 | |
|      int nent;
 | |
|      const struct timespec *timeout;
 | |
| {
 | |
|   struct waitlist waitlist[nent];
 | |
|   struct requestlist *requestlist[nent];
 | |
|   pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
 | |
|   int cnt;
 | |
|   int result = 0;
 | |
|   int dummy;
 | |
|   int none = 1;
 | |
| 
 | |
|   /* Request the mutex.  */
 | |
|   pthread_mutex_lock (&__aio_requests_mutex);
 | |
| 
 | |
|   /* There is not yet a finished request.  Signal the request that
 | |
|      we are working for it.  */
 | |
|   for (cnt = 0; cnt < nent; ++cnt)
 | |
|     if (list[cnt] != NULL && list[cnt]->__error_code == EINPROGRESS)
 | |
|       {
 | |
| 	requestlist[cnt] = __aio_find_req ((aiocb_union *) list[cnt]);
 | |
| 
 | |
| 	if (requestlist[cnt] != NULL)
 | |
| 	  {
 | |
| 	    waitlist[cnt].cond = &cond;
 | |
| 	    waitlist[cnt].next = requestlist[cnt]->waiting;
 | |
| 	    waitlist[cnt].counterp = &dummy;
 | |
| 	    waitlist[cnt].sigevp = NULL;
 | |
| 	    waitlist[cnt].caller_pid = 0;	/* Not needed.  */
 | |
| 	    requestlist[cnt]->waiting = &waitlist[cnt];
 | |
| 	    none = 0;
 | |
| 	  }
 | |
|       }
 | |
| 
 | |
|   /* If there is a not finished request wait for it.  */
 | |
|   if (!none)
 | |
|     {
 | |
|       int oldstate;
 | |
| 
 | |
|       /* Since `pthread_cond_wait'/`pthread_cond_timedwait' are cancelation
 | |
| 	 points we must be careful.  We added entries to the waiting lists
 | |
| 	 which we must remove.  So defer cancelation for now.  */
 | |
|       pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate);
 | |
| 
 | |
|       if (timeout == NULL)
 | |
| 	result = pthread_cond_wait (&cond, &__aio_requests_mutex);
 | |
|       else
 | |
| 	result = pthread_cond_timedwait (&cond, &__aio_requests_mutex,
 | |
| 					 timeout);
 | |
| 
 | |
|       /* Now remove the entry in the waiting list for all requests
 | |
| 	 which didn't terminate.  */
 | |
|       for (cnt = 0; cnt < nent; ++cnt)
 | |
| 	if (list[cnt] != NULL && list[cnt]->__error_code == EINPROGRESS
 | |
| 	    && requestlist[cnt] != NULL)
 | |
| 	  {
 | |
| 	    struct waitlist **listp = &requestlist[cnt]->waiting;
 | |
| 
 | |
| 	    /* There is the chance that we cannot find our entry anymore.
 | |
| 	       This could happen if the request terminated and restarted
 | |
| 	       again.  */
 | |
| 	    while (*listp != NULL && *listp != &waitlist[cnt])
 | |
| 	      listp = &(*listp)->next;
 | |
| 
 | |
| 	    if (*listp != NULL)
 | |
| 	      *listp = (*listp)->next;
 | |
| 	  }
 | |
| 
 | |
|       /* Now it's time to restore the cancelation state.  */
 | |
|       pthread_setcancelstate (oldstate, NULL);
 | |
| 
 | |
|       /* Release the conditional variable.  */
 | |
|       if (pthread_cond_destroy (&cond) != 0)
 | |
| 	/* This must never happen.  */
 | |
| 	abort ();
 | |
| 
 | |
|       if (result != 0)
 | |
| 	{
 | |
| 	  /* An error occurred.  Possibly it's EINTR.  We have to translate
 | |
| 	     the timeout error report of `pthread_cond_timedwait' to the
 | |
| 	     form expected from `aio_suspend'.  */
 | |
| 	  if (result == ETIMEDOUT)
 | |
| 	    __set_errno (EAGAIN);
 | |
| 
 | |
| 	  result = -1;
 | |
| 	}
 | |
|     }
 | |
| 
 | |
|   /* Release the mutex.  */
 | |
|   pthread_mutex_unlock (&__aio_requests_mutex);
 | |
| 
 | |
|   return result;
 | |
| }
 | |
| 
 | |
| weak_alias (aio_suspend, aio_suspend64)
 |