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/* Suspend until termination of a requests.
Copyright (C) 1997, 1998, 1999, 2000, 2002 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; 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
implementations 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 <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <sys/time.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;
bool any = false;
/* 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)
{
if (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];
any = true;
}
else
/* We will never suspend. */
break;
}
else
/* We will never suspend. */
break;
}
/* If there is no finished request wait for it. In any case we have
to dequeue the requests if we enqueued them. */
if (any)
{
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);
/* Only if none of the entries is NULL or finished to be wait. */
if (cnt == nent)
{
if (timeout == NULL)
result = pthread_cond_wait (&cond, &__aio_requests_mutex);
else
{
/* We have to convert the relative timeout value into an
absolute time value with pthread_cond_timedwait expects. */
struct timeval now;
struct timespec abstime;
__gettimeofday (&now, NULL);
abstime.tv_nsec = timeout->tv_nsec + now.tv_usec * 1000;
abstime.tv_sec = timeout->tv_sec + now.tv_sec;
if (abstime.tv_nsec >= 1000000000)
{
abstime.tv_nsec -= 1000000000;
abstime.tv_sec += 1;
}
result = pthread_cond_timedwait (&cond, &__aio_requests_mutex,
&abstime);
}
}
/* Now remove the entry in the waiting list for all requests
which didn't terminate. */
while (cnt-- > 0)
if (list[cnt] != NULL && list[cnt]->__error_code == EINPROGRESS)
{
struct waitlist **listp;
assert (requestlist[cnt] != NULL);
/* There is the chance that we cannot find our entry anymore.
This could happen if the request terminated and restarted
again. */
listp = &requestlist[cnt]->waiting;
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 (__builtin_expect (pthread_cond_destroy (&cond) != 0, 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)
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