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/* Copyright (C) 2001-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
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/>. */
#include <errno.h>
#include <netdb.h>
#include <pthread.h>
#include <stdlib.h>
#include <sys/time.h>
#include <gai_misc.h>
int
gai_suspend (const struct gaicb *const list[], int ent,
const struct timespec *timeout)
{
struct waitlist waitlist[ent];
struct requestlist *requestlist[ent];
#ifndef DONT_NEED_GAI_MISC_COND
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
#endif
int cnt;
unsigned int cntr = 1;
int none = 1;
int result;
/* Request the mutex. */
pthread_mutex_lock (&__gai_requests_mutex);
/* There is not yet a finished request. Signal the request that
we are working for it. */
for (cnt = 0; cnt < ent; ++cnt)
if (list[cnt] != NULL && list[cnt]->__return == EAI_INPROGRESS)
{
requestlist[cnt] = __gai_find_request (list[cnt]);
if (requestlist[cnt] != NULL)
{
#ifndef DONT_NEED_GAI_MISC_COND
waitlist[cnt].cond = &cond;
#endif
waitlist[cnt].next = requestlist[cnt]->waiting;
waitlist[cnt].counterp = &cntr;
waitlist[cnt].sigevp = NULL;
waitlist[cnt].caller_pid = 0; /* Not needed. */
requestlist[cnt]->waiting = &waitlist[cnt];
none = 0;
}
}
if (none)
{
if (cnt < ent)
/* There is an entry which is finished. */
result = 0;
else
result = EAI_ALLDONE;
}
else
{
/* There is no request done but some are still being worked on. */
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);
#ifdef DONT_NEED_GAI_MISC_COND
result = 0;
GAI_MISC_WAIT (result, cntr, timeout, 1);
#else
if (timeout == NULL)
result = pthread_cond_wait (&cond, &__gai_requests_mutex);
else
{
/* We have to convert the relative timeout value into an
absolute time value with pthread_cond_timedwait expects. */
struct timespec now;
struct timespec abstime;
__clock_gettime (CLOCK_REALTIME, &now);
abstime.tv_nsec = timeout->tv_nsec + now.tv_nsec;
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, &__gai_requests_mutex,
&abstime);
}
#endif
/* Now remove the entry in the waiting list for all requests
which didn't terminate. */
for (cnt = 0; cnt < ent; ++cnt)
if (list[cnt] != NULL && list[cnt]->__return == EAI_INPROGRESS
&& requestlist[cnt] != NULL)
{
struct waitlist **listp = &requestlist[cnt]->waiting;
/* There is the chance that we cannot find our entry anymore.
This could happen if the request terminated and restarted
again. */
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);
#ifndef DONT_NEED_GAI_MISC_COND
/* Release the conditional variable. */
if (pthread_cond_destroy (&cond) != 0)
/* This must never happen. */
abort ();
#endif
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 `gai_suspend'. */
if (__glibc_likely (result == ETIMEDOUT))
result = EAI_AGAIN;
else if (result == EINTR)
result = EAI_INTR;
else
result = EAI_SYSTEM;
}
}
/* Release the mutex. */
pthread_mutex_unlock (&__gai_requests_mutex);
return result;
}
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