mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-09 04:11:27 +08:00
2b778ceb40
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
118 lines
3.4 KiB
C
118 lines
3.4 KiB
C
/* Acquire a rwlock for writing. Generic version.
|
|
Copyright (C) 2002-2021 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <pthread.h>
|
|
#include <assert.h>
|
|
#include <time.h>
|
|
|
|
#include <pt-internal.h>
|
|
|
|
/* Acquire RWLOCK for writing blocking until *ABSTIME if we cannot get
|
|
it. As a special GNU extension, if ABSTIME is NULL then the wait
|
|
shall not time out. */
|
|
int
|
|
__pthread_rwlock_timedwrlock_internal (struct __pthread_rwlock *rwlock,
|
|
clockid_t clockid,
|
|
const struct timespec *abstime)
|
|
{
|
|
error_t err;
|
|
int drain;
|
|
struct __pthread *self;
|
|
|
|
__pthread_spin_wait (&rwlock->__lock);
|
|
if (__pthread_spin_trylock (&rwlock->__held) == 0)
|
|
/* Successfully acquired the lock. */
|
|
{
|
|
assert (rwlock->__readerqueue == 0);
|
|
assert (rwlock->__writerqueue == 0);
|
|
assert (rwlock->__readers == 0);
|
|
|
|
__pthread_spin_unlock (&rwlock->__lock);
|
|
return 0;
|
|
}
|
|
|
|
/* The lock is busy. */
|
|
|
|
if (abstime != NULL && ! valid_nanoseconds (abstime->tv_nsec))
|
|
{
|
|
__pthread_spin_unlock (&rwlock->__lock);
|
|
return EINVAL;
|
|
}
|
|
|
|
self = _pthread_self ();
|
|
|
|
/* Add ourselves to the queue. */
|
|
__pthread_enqueue (&rwlock->__writerqueue, self);
|
|
__pthread_spin_unlock (&rwlock->__lock);
|
|
|
|
/* Block the thread. */
|
|
if (abstime != NULL)
|
|
err = __pthread_timedblock (self, abstime, clockid);
|
|
else
|
|
{
|
|
err = 0;
|
|
__pthread_block (self);
|
|
}
|
|
|
|
__pthread_spin_wait (&rwlock->__lock);
|
|
if (self->prevp == NULL)
|
|
/* Another thread removed us from the queue, which means a wakeup message
|
|
has been sent. It was either consumed while we were blocking, or
|
|
queued after we timed out and before we acquired the rwlock lock, in
|
|
which case the message queue must be drained. */
|
|
drain = err ? 1 : 0;
|
|
else
|
|
{
|
|
/* We're still in the queue. Noone attempted to wake us up, i.e. we
|
|
timed out. */
|
|
__pthread_dequeue (self);
|
|
drain = 0;
|
|
}
|
|
__pthread_spin_unlock (&rwlock->__lock);
|
|
|
|
if (drain)
|
|
__pthread_block (self);
|
|
|
|
if (err)
|
|
{
|
|
assert (err == ETIMEDOUT);
|
|
return err;
|
|
}
|
|
|
|
assert (rwlock->__readers == 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
__pthread_rwlock_timedwrlock (struct __pthread_rwlock *rwlock,
|
|
const struct timespec *abstime)
|
|
{
|
|
return __pthread_rwlock_timedwrlock_internal (rwlock, CLOCK_REALTIME, abstime);
|
|
}
|
|
weak_alias (__pthread_rwlock_timedwrlock, pthread_rwlock_timedwrlock)
|
|
|
|
int
|
|
__pthread_rwlock_clockwrlock (struct __pthread_rwlock *rwlock,
|
|
clockid_t clockid,
|
|
const struct timespec *abstime)
|
|
{
|
|
return __pthread_rwlock_timedwrlock_internal (rwlock, clockid, abstime);
|
|
}
|
|
weak_alias (__pthread_rwlock_clockwrlock, pthread_rwlock_clockwrlock)
|