glibc/rt/aio_notify.c

120 lines
3.4 KiB
C

/* Notify initiator of AIO request.
Copyright (C) 1997,98,99,2000,01 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. */
#include <errno.h>
#include <pthread.h>
#include <stdlib.h>
#include <unistd.h>
#include "aio_misc.h"
static void *
notify_func_wrapper (void *arg)
{
struct sigevent *sigev = arg;
sigev->sigev_notify_function (sigev->sigev_value);
return NULL;
}
int
internal_function
__aio_notify_only (struct sigevent *sigev, pid_t caller_pid)
{
int result = 0;
/* Send the signal to notify about finished processing of the request. */
if (sigev->sigev_notify == SIGEV_THREAD)
{
/* We have to start a thread. */
pthread_t tid;
pthread_attr_t attr, *pattr;
pattr = (pthread_attr_t *) sigev->sigev_notify_attributes;
if (pattr == NULL)
{
pthread_attr_init (&attr);
pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
pattr = &attr;
}
if (pthread_create (&tid, pattr, notify_func_wrapper, sigev) < 0)
result = -1;
}
else if (sigev->sigev_notify == SIGEV_SIGNAL)
{
/* We have to send a signal. */
#if _POSIX_REALTIME_SIGNALS
/* Note that the standard gives us the option of using a plain
non-queuing signal here when SA_SIGINFO is not set for the signal. */
if (__aio_sigqueue (sigev->sigev_signo, sigev->sigev_value, caller_pid)
< 0)
result = -1;
#else
/* There are no queued signals on this system at all. */
result = raise (sigev->sigev_signo);
#endif
}
return result;
}
void
internal_function
__aio_notify (struct requestlist *req)
{
struct waitlist *waitlist;
struct aiocb *aiocbp = &req->aiocbp->aiocb;
if (__aio_notify_only (&aiocbp->aio_sigevent, req->caller_pid) != 0)
{
/* XXX What shall we do if already an error is set by
read/write/fsync? */
aiocbp->__error_code = errno;
aiocbp->__return_value = -1;
}
/* Now also notify possibly waiting threads. */
waitlist = req->waiting;
while (waitlist != NULL)
{
struct waitlist *next = waitlist->next;
/* Decrement the counter. This is used in both cases. */
--*waitlist->counterp;
if (waitlist->sigevp == NULL)
pthread_cond_signal (waitlist->cond);
else
/* This is part of a asynchronous `lio_listio' operation. If
this request is the last one, send the signal. */
if (*waitlist->counterp == 0)
{
__aio_notify_only (waitlist->sigevp, waitlist->caller_pid);
/* This is tricky. See lio_listio.c for the reason why
this works. */
free ((void *) waitlist->counterp);
}
waitlist = next;
}
}