sysdeps/pthread/lio_listio64.c

   1 /* Enqueue and list of read or write requests, 64bit offset version.
   2    Copyright (C) 1997, 1998, 1999, 2003 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 Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the 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    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <aio.h>
  22 #include <errno.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25
  26 #include "aio_misc.h"
  27
  28
  29 /* We need this special structure to handle asynchronous I/O.  */
  30 struct async_waitlist
  31   {
  32     int counter;
  33     struct sigevent sigev;
  34     struct waitlist list[0];
  35   };
  36
  37
  38 int
  39 lio_listio64 (mode, list, nent, sig)
  40      int mode;
  41      struct aiocb64 *const list[];
  42      int nent;
  43      struct sigevent *sig;
  44 {
  45   struct sigevent defsigev;
  46   struct requestlist *requests[nent];
  47   int cnt;
  48   volatile int total = 0;
  49   int result = 0;
  50
  51   /* Check arguments.  */
  52   if (mode != LIO_WAIT && mode != LIO_NOWAIT)
  53     {
  54       __set_errno (EINVAL);
  55       return -1;
  56     }
  57
  58   if (sig == NULL)
  59     {
  60       defsigev.sigev_notify = SIGEV_NONE;
  61       sig = &defsigev;
  62     }
  63
  64   /* Request the mutex.  */
  65   pthread_mutex_lock (&__aio_requests_mutex);
  66
  67   /* Now we can enqueue all requests.  Since we already acquired the
  68      mutex the enqueue function need not do this.  */
  69   for (cnt = 0; cnt < nent; ++cnt)
  70     if (list[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP)
  71       {
  72         requests[cnt] = __aio_enqueue_request ((aiocb_union *) list[cnt],
  73                                                (list[cnt]->aio_lio_opcode
  74                                                 | 128));
  75         if (requests[cnt] != NULL)
  76           /* Successfully enqueued.  */
  77           ++total;
  78         else
  79           /* Signal that we've seen an error.  `errno' and the error code
  80              of the aiocb will tell more.  */
  81           result = -1;
  82       }
  83
  84   if (total == 0)
  85     {
  86       /* We don't have anything to do except signalling if we work
  87          asynchronously.  */
  88
  89       /* Release the mutex.  We do this before raising a signal since the
  90          signal handler might do a `siglongjmp' and then the mutex is
  91          locked forever.  */
  92       pthread_mutex_unlock (&__aio_requests_mutex);
  93
  94       if (mode == LIO_NOWAIT)
  95         __aio_notify_only (sig,
  96                            sig->sigev_notify == SIGEV_SIGNAL ? getpid () : 0);
  97
  98       return result;
  99     }
 100   else if (mode == LIO_WAIT)
 101     {
 102       pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
 103       struct waitlist waitlist[nent];
 104       int oldstate;
 105
 106       total = 0;
 107       for (cnt = 0; cnt < nent; ++cnt)
 108         if (list[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP
 109             && requests[cnt] != NULL)
 110           {
 111             waitlist[cnt].cond = &cond;
 112             waitlist[cnt].next = requests[cnt]->waiting;
 113             waitlist[cnt].counterp = &total;
 114             waitlist[cnt].sigevp = NULL;
 115             waitlist[cnt].caller_pid = 0;       /* Not needed.  */
 116             requests[cnt]->waiting = &waitlist[cnt];
 117             ++total;
 118           }
 119
 120       /* Since `pthread_cond_wait'/`pthread_cond_timedwait' are cancelation
 121          points we must be careful.  We added entries to the waiting lists
 122          which we must remove.  So defer cancelation for now.  */
 123       pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate);
 124
 125       while (total > 0)
 126         pthread_cond_wait (&cond, &__aio_requests_mutex);
 127
 128       /* Now it's time to restore the cancelation state.  */
 129       pthread_setcancelstate (oldstate, NULL);
 130
 131       /* Release the conditional variable.  */
 132       if (pthread_cond_destroy (&cond) != 0)
 133         /* This must never happen.  */
 134         abort ();
 135     }
 136   else
 137     {
 138       struct async_waitlist *waitlist;
 139
 140       waitlist = (struct async_waitlist *)
 141         malloc (sizeof (struct async_waitlist)
 142                 + (nent * sizeof (struct waitlist)));
 143
 144       if (waitlist == NULL)
 145         {
 146           __set_errno (EAGAIN);
 147           result = -1;
 148         }
 149       else
 150         {
 151           pid_t caller_pid = sig->sigev_notify == SIGEV_SIGNAL ? getpid () : 0;
 152           total = 0;
 153
 154           for (cnt = 0; cnt < nent; ++cnt)
 155             if (list[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP
 156                 && requests[cnt] != NULL)
 157               {
 158                 waitlist->list[cnt].cond = NULL;
 159                 waitlist->list[cnt].next = requests[cnt]->waiting;
 160                 waitlist->list[cnt].counterp = &waitlist->counter;
 161                 waitlist->list[cnt].sigevp = &waitlist->sigev;
 162                 waitlist->list[cnt].caller_pid = caller_pid;
 163                 requests[cnt]->waiting = &waitlist->list[cnt];
 164                 ++total;
 165               }
 166
 167           waitlist->counter = total;
 168           waitlist->sigev = *sig;
 169         }
 170     }
 171
 172   /* Release the mutex.  */
 173   pthread_mutex_unlock (&__aio_requests_mutex);
 174
 175   return result;
 176 }