rt/aio_notify.c

   1 /* Notify initiator of AIO request.
   2    Copyright (C) 1997 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <pthread.h>
  22 #include <stdlib.h>
  23 #include "aio_misc.h"
  24
  25 int
  26 __aio_notify_only (struct sigevent *sigev)
  27 {
  28   int result = 0;
  29
  30   /* Send the signal to notify about finished processing of the request.  */
  31   if (sigev->sigev_notify == SIGEV_THREAD)
  32     {
  33       /* We have to start a thread.  */
  34       pthread_t tid;
  35       pthread_attr_t attr, *pattr;
  36
  37       pattr = (pthread_attr_t *) sigev->sigev_notify_attributes;
  38       if (pattr == NULL)
  39         {
  40           pthread_attr_init (&attr);
  41           pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
  42           pattr = &attr;
  43         }
  44
  45       if (pthread_create (&tid, pattr,
  46                           (void *(*) (void *)) sigev->sigev_notify_function,
  47                           sigev->sigev_value.sival_ptr) < 0)
  48         result = -1;
  49     }
  50   else if (sigev->sigev_notify == SIGEV_SIGNAL)
  51     /* We have to send a signal.  */
  52     if (__aio_sigqueue (sigev->sigev_signo, sigev->sigev_value) < 0)
  53       result = -1;
  54
  55   return result;
  56 }
  57
  58
  59 void
  60 __aio_notify (struct requestlist *req)
  61 {
  62   struct waitlist *waitlist;
  63   struct aiocb *aiocbp = &req->aiocbp->aiocb;
  64
  65   if (__aio_notify_only (&aiocbp->aio_sigevent) != 0)
  66     {
  67       /* XXX What shall we do if already an error is set by
  68          read/write/fsync?  */
  69       aiocbp->__error_code = errno;
  70       aiocbp->__return_value = -1;
  71     }
  72
  73   /* Now also notify possibly waiting threads.  */
  74   waitlist = req->waiting;
  75   while (waitlist != NULL)
  76     {
  77       struct waitlist *next = waitlist->next;
  78
  79       /* Decrement the counter.  This is used in both cases.  */
  80       --*waitlist->counterp;
  81
  82       if (waitlist->sigevp == NULL)
  83         pthread_cond_signal (waitlist->cond);
  84       else
  85         /* This is part of a asynchronous `lio_listio' operation.  If
  86            this request is the last one, send the signal.  */
  87         if (*waitlist->counterp == 0)
  88           {
  89             __aio_notify_only (waitlist->sigevp);
  90             /* This is tricky.  See lio_listio.c for the reason why
  91                this works.  */
  92             free ((void *) waitlist->counterp);
  93           }
  94
  95       waitlist = next;
  96     }
  97 }