glibc/sysdeps/htl/pt-rwlock-timedwrlock.c
Paul Eggert 5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00

104 lines
3.0 KiB
C

/* Acquire a rwlock for writing. Generic version.
Copyright (C) 2002-2019 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 <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,
const struct timespec *abstime)
{
error_t err;
int drain;
struct __pthread *self;
__pthread_spin_lock (&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 && (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000))
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, CLOCK_REALTIME);
else
{
err = 0;
__pthread_block (self);
}
__pthread_spin_lock (&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, abstime);
}
weak_alias (__pthread_rwlock_timedwrlock, pthread_rwlock_timedwrlock)