143 lines
3.8 KiB
C
143 lines
3.8 KiB
C
/* Cancel requests associated with given file descriptor.
|
|
Copyright (C) 1997, 1998, 2000 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_cancel and aio_cancel64 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_cancel64 has no prototype. */
|
|
#define aio_cancel64 XXX
|
|
#include <aio.h>
|
|
/* And undo the hack. */
|
|
#undef aio_cancel64
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
|
|
#include "aio_misc.h"
|
|
|
|
|
|
int
|
|
aio_cancel (fildes, aiocbp)
|
|
int fildes;
|
|
struct aiocb *aiocbp;
|
|
{
|
|
struct requestlist *req = NULL;
|
|
int result = AIO_ALLDONE;
|
|
|
|
/* Request the mutex. */
|
|
pthread_mutex_lock (&__aio_requests_mutex);
|
|
|
|
/* We are asked to cancel a specific AIO request. */
|
|
if (aiocbp != NULL)
|
|
{
|
|
/* If the AIO request is not for this descriptor it has no value
|
|
to look for the request block. */
|
|
if (aiocbp->aio_fildes == fildes)
|
|
{
|
|
struct requestlist *last = NULL;
|
|
|
|
req = __aio_find_req_fd (fildes);
|
|
|
|
if (req == NULL)
|
|
{
|
|
not_found:
|
|
pthread_mutex_unlock (&__aio_requests_mutex);
|
|
__set_errno (EINVAL);
|
|
return -1;
|
|
}
|
|
|
|
while (req->aiocbp != (aiocb_union *) aiocbp)
|
|
{
|
|
last = req;
|
|
req = req->next_prio;
|
|
if (req == NULL)
|
|
goto not_found;
|
|
}
|
|
|
|
/* Don't remove the entry if a thread is already working on it. */
|
|
if (req->running == allocated)
|
|
{
|
|
result = AIO_NOTCANCELED;
|
|
req = NULL;
|
|
}
|
|
else
|
|
{
|
|
/* We can remove the entry. */
|
|
__aio_remove_request (last, req, 0);
|
|
|
|
result = AIO_CANCELED;
|
|
|
|
req->next_prio = NULL;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Find the beginning of the list of all requests for this
|
|
desriptor. */
|
|
req = __aio_find_req_fd (fildes);
|
|
|
|
/* If any request is worked on by a thread it must be the first.
|
|
So either we can delete all requests or all but the first. */
|
|
if (req != NULL)
|
|
{
|
|
if (req->running == allocated)
|
|
{
|
|
struct requestlist *old = req;
|
|
req = req->next_prio;
|
|
old->next_prio = NULL;
|
|
|
|
result = AIO_NOTCANCELED;
|
|
|
|
if (req != NULL)
|
|
__aio_remove_request (old, req, 1);
|
|
}
|
|
else
|
|
{
|
|
result = AIO_CANCELED;
|
|
|
|
/* We can remove the entry. */
|
|
__aio_remove_request (NULL, req, 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Mark requests as canceled and send signal. */
|
|
while (req != NULL)
|
|
{
|
|
struct requestlist *old = req;
|
|
assert (req->running == yes || req->running == queued);
|
|
req->aiocbp->aiocb.__error_code = ECANCELED;
|
|
req->aiocbp->aiocb.__return_value = -1;
|
|
__aio_notify (req);
|
|
req = req->next_prio;
|
|
__aio_free_request (old);
|
|
}
|
|
|
|
/* Release the mutex. */
|
|
pthread_mutex_unlock (&__aio_requests_mutex);
|
|
|
|
return result;
|
|
}
|
|
|
|
weak_alias (aio_cancel, aio_cancel64)
|