mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-25 04:01:10 +00:00
122 lines
3.8 KiB
C
122 lines
3.8 KiB
C
/* Copyright (C) 2006-2015 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
/* We define a special synchronization primitive for AIO. POSIX
|
|
conditional variables would be ideal but the pthread_cond_*wait
|
|
operations do not return on EINTR. This is a requirement for
|
|
correct aio_suspend and lio_listio implementations. */
|
|
|
|
#include <assert.h>
|
|
#include <signal.h>
|
|
#include <nptl/pthreadP.h>
|
|
#include <lowlevellock.h>
|
|
|
|
#define DONT_NEED_GAI_MISC_COND 1
|
|
|
|
#define GAI_MISC_NOTIFY(waitlist) \
|
|
do { \
|
|
if (*waitlist->counterp > 0 && --*waitlist->counterp == 0) \
|
|
lll_futex_wake (waitlist->counterp, 1, LLL_PRIVATE); \
|
|
} while (0)
|
|
|
|
#define GAI_MISC_WAIT(result, futex, timeout, cancel) \
|
|
do { \
|
|
volatile int *futexaddr = &futex; \
|
|
int oldval = futex; \
|
|
\
|
|
if (oldval != 0) \
|
|
{ \
|
|
pthread_mutex_unlock (&__gai_requests_mutex); \
|
|
\
|
|
int oldtype; \
|
|
if (cancel) \
|
|
oldtype = LIBC_CANCEL_ASYNC (); \
|
|
\
|
|
int status; \
|
|
do \
|
|
{ \
|
|
status = lll_futex_timed_wait (futexaddr, oldval, timeout, \
|
|
LLL_PRIVATE); \
|
|
if (status != -EWOULDBLOCK) \
|
|
break; \
|
|
\
|
|
oldval = *futexaddr; \
|
|
} \
|
|
while (oldval != 0); \
|
|
\
|
|
if (cancel) \
|
|
LIBC_CANCEL_RESET (oldtype); \
|
|
\
|
|
if (status == -EINTR) \
|
|
result = EINTR; \
|
|
else if (status == -ETIMEDOUT) \
|
|
result = EAGAIN; \
|
|
else \
|
|
assert (status == 0 || status == -EWOULDBLOCK); \
|
|
\
|
|
pthread_mutex_lock (&__gai_requests_mutex); \
|
|
} \
|
|
} while (0)
|
|
|
|
|
|
#define gai_start_notify_thread __gai_start_notify_thread
|
|
#define gai_create_helper_thread __gai_create_helper_thread
|
|
|
|
extern inline void
|
|
__gai_start_notify_thread (void)
|
|
{
|
|
sigset_t ss;
|
|
sigemptyset (&ss);
|
|
int sigerr = pthread_sigmask (SIG_SETMASK, &ss, NULL);
|
|
assert_perror (sigerr);
|
|
}
|
|
|
|
extern inline int
|
|
__gai_create_helper_thread (pthread_t *threadp, void *(*tf) (void *),
|
|
void *arg)
|
|
{
|
|
pthread_attr_t attr;
|
|
|
|
/* Make sure the thread is created detached. */
|
|
pthread_attr_init (&attr);
|
|
pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
|
|
|
|
/* The helper thread needs only very little resources. */
|
|
(void) pthread_attr_setstacksize (&attr,
|
|
__pthread_get_minstack (&attr)
|
|
+ 4 * PTHREAD_STACK_MIN);
|
|
|
|
/* Block all signals in the helper thread. To do this thoroughly we
|
|
temporarily have to block all signals here. */
|
|
sigset_t ss;
|
|
sigset_t oss;
|
|
sigfillset (&ss);
|
|
int sigerr = pthread_sigmask (SIG_SETMASK, &ss, &oss);
|
|
assert_perror (sigerr);
|
|
|
|
int ret = pthread_create (threadp, &attr, tf, arg);
|
|
|
|
/* Restore the signal mask. */
|
|
sigerr = pthread_sigmask (SIG_SETMASK, &oss, NULL);
|
|
assert_perror (sigerr);
|
|
|
|
(void) pthread_attr_destroy (&attr);
|
|
return ret;
|
|
}
|
|
|
|
#include_next <gai_misc.h>
|