/* Suspend until termination of a requests.
Copyright (C) 1997-2020 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, see
<https://www.gnu.org/licenses/>. */
/* 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 <libc-lock.h>
#include <aio_misc.h>
struct clparam
{
const struct aiocb *const *list;
struct waitlist *waitlist;
struct requestlist **requestlist;
#ifndef DONT_NEED_AIO_MISC_COND
pthread_cond_t *cond;
#endif
int nent;
};
static void
cleanup (void *arg)
{
#ifdef DONT_NEED_AIO_MISC_COND
/* Acquire the mutex. If pthread_cond_*wait is used this would
happen implicitly. */
pthread_mutex_lock (&__aio_requests_mutex);
#endif
const struct clparam *param = (const struct clparam *) arg;
/* Now remove the entry in the waiting list for all requests
which didn't terminate. */
int cnt = param->nent;
while (cnt-- > 0)
if (param->list[cnt] != NULL
&& param->list[cnt]->__error_code == EINPROGRESS)
{
struct waitlist **listp;
assert (param->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 = ¶m->requestlist[cnt]->waiting;
while (*listp != NULL && *listp != ¶m->waitlist[cnt])
listp = &(*listp)->next;
if (*listp != NULL)
*listp = (*listp)->next;
}
#ifndef DONT_NEED_AIO_MISC_COND
/* Release the conditional variable. */
(void) pthread_cond_destroy (param->cond);
#endif
/* Release the mutex. */
pthread_mutex_unlock (&__aio_requests_mutex);
}
#ifdef DONT_NEED_AIO_MISC_COND
static int
__attribute__ ((noinline))
do_aio_misc_wait (unsigned int *cntr, const struct __timespec64 *timeout)
{
int result = 0;
AIO_MISC_WAIT (result, *cntr, timeout, 1);
return result;
}
#endif
int
__aio_suspend_time64 (const struct aiocb *const list[], int nent,
const struct __timespec64 *timeout)
{
if (__glibc_unlikely (nent < 0))
{
__set_errno (EINVAL);
return -1;
}
struct waitlist waitlist[nent];
struct requestlist *requestlist[nent];
#ifndef DONT_NEED_AIO_MISC_COND
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
#endif
int cnt;
bool any = false;
int result = 0;
unsigned int cntr = 1;
/* 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)
{
#ifndef DONT_NEED_AIO_MISC_COND
waitlist[cnt].cond = &cond;
#endif
waitlist[cnt].result = NULL;
waitlist[cnt].next = requestlist[cnt]->waiting;
waitlist[cnt].counterp = &cntr;
waitlist[cnt].sigevp = NULL;
requestlist[cnt]->waiting = &waitlist[cnt];
any = true;
}
else
/* We will never suspend. */
break;
}
else
/* We will never suspend. */
break;
}
struct __timespec64 ts;
if (timeout != NULL)
{
__clock_gettime64 (CLOCK_MONOTONIC, &ts);
ts.tv_sec += timeout->tv_sec;
ts.tv_nsec += timeout->tv_nsec;
if (ts.tv_nsec >= 1000000000)
{
ts.tv_nsec -= 1000000000;
ts.tv_sec++;
}
}
/* Only if none of the entries is NULL or finished to be wait. */
if (cnt == nent && any)
{
struct clparam clparam =
{
.list = list,
.waitlist = waitlist,
.requestlist = requestlist,
#ifndef DONT_NEED_AIO_MISC_COND
.cond = &cond,
#endif
.nent = nent
};
pthread_cleanup_push (cleanup, &clparam);
#ifdef DONT_NEED_AIO_MISC_COND
result = do_aio_misc_wait (&cntr, timeout == NULL ? NULL : &ts);
#else
struct timespec ts32 = valid_timespec64_to_timespec (ts);
result = pthread_cond_timedwait (&cond, &__aio_requests_mutex,
timeout == NULL ? NULL : &ts32);
#endif
pthread_cleanup_pop (0);
}
/* 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;
}
#ifndef DONT_NEED_AIO_MISC_COND
/* Release the conditional variable. */
if (__glibc_unlikely (pthread_cond_destroy (&cond) != 0))
/* This must never happen. */
abort ();
#endif
if (result != 0)
{
#ifndef DONT_NEED_AIO_MISC_COND
/* An error occurred. Possibly it's ETIMEDOUT. 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);
else
#endif
__set_errno (result);
result = -1;
}
/* Release the mutex. */
pthread_mutex_unlock (&__aio_requests_mutex);
return result;
}
#if __TIMESIZE != 64
librt_hidden_def (__aio_suspend_time64)
int
__aio_suspend (const struct aiocb *const list[], int nent,
const struct timespec *timeout)
{
struct __timespec64 ts64;
if (timeout != NULL)
ts64 = valid_timespec_to_timespec64 (*timeout);
return __aio_suspend_time64 (list, nent, timeout != NULL ? &ts64 : NULL);
}
#endif
weak_alias (__aio_suspend, aio_suspend)
weak_alias (aio_suspend, aio_suspend64)