mirror of
https://sourceware.org/git/glibc.git
synced 2024-09-21 00:50:04 +00:00
e59660bc25
* tst-initializers1.c: Show through exit code which test failed. * pthread_rwlock_init.c: Also initialize __shared field. * sysdeps/unix/sysv/linux/i386/bits/pthreadtypes.h: Split __flags element in rwlock structure into four byte elements. One of them is the new __shared element. * sysdeps/unix/sysv/linux/x86_64/bits/pthreadtypes.h [__WORDSIZE=32]: Likewise. [__WORDSIZE=64]: Renamed __pad1 element int rwlock structire to __shared, adjust names of other padding elements. * sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h: Likewise. * sysdeps/pthread/pthread.h: Adjust rwlock initializers. * sysdeps/unix/sysv/linux/lowlevelrwlock.sym: Add PSHARED. * sysdeps/unix/sysv/linux/powerpc/lowlevellock.h: Define FUTEX_PRIVATE_FLAG. * sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S: Change main futex to use private operations if possible. * sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_timedrdlock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_timedwrlock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_unlock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_wrlock.S: Likewise.
83 lines
2.9 KiB
C
83 lines
2.9 KiB
C
/* Copyright (C) 2002, 2007 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
|
|
|
|
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, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include "pthreadP.h"
|
|
#include <kernel-features.h>
|
|
|
|
|
|
static const struct pthread_rwlockattr default_attr =
|
|
{
|
|
.lockkind = PTHREAD_RWLOCK_DEFAULT_NP,
|
|
.pshared = PTHREAD_PROCESS_PRIVATE
|
|
};
|
|
|
|
|
|
int
|
|
__pthread_rwlock_init (rwlock, attr)
|
|
pthread_rwlock_t *rwlock;
|
|
const pthread_rwlockattr_t *attr;
|
|
{
|
|
const struct pthread_rwlockattr *iattr;
|
|
|
|
iattr = ((const struct pthread_rwlockattr *) attr) ?: &default_attr;
|
|
|
|
rwlock->__data.__lock = 0;
|
|
rwlock->__data.__nr_readers = 0;
|
|
rwlock->__data.__readers_wakeup = 0;
|
|
rwlock->__data.__writer_wakeup = 0;
|
|
rwlock->__data.__nr_readers_queued = 0;
|
|
rwlock->__data.__nr_writers_queued = 0;
|
|
rwlock->__data.__writer = 0;
|
|
|
|
rwlock->__data.__flags
|
|
= iattr->lockkind == PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP;
|
|
|
|
/* The __SHARED field is computed to minimize the work that needs to
|
|
be done while handling the futex. There are two inputs: the
|
|
availability of private futexes and whether the rwlock is shared
|
|
or private. Unfortunately the value of a private rwlock is
|
|
fixed: it must be zero. The PRIVATE_FUTEX flag has the value
|
|
0x80 in case private futexes are available and zero otherwise.
|
|
This leads to the following table:
|
|
|
|
| pshared | result
|
|
| shared private | shared private |
|
|
------------+-----------------+-----------------+
|
|
!avail 0 | 0 0 | 0 0 |
|
|
avail 0x80 | 0x80 0 | 0 0x80 |
|
|
|
|
If the pshared value is in locking functions XORed with avail
|
|
we get the expected result. */
|
|
#ifdef __ASSUME_PRIVATE_FUTEX
|
|
rwlock->__data.__shared = (iattr->pshared == PTHREAD_PROCESS_PRIVATE
|
|
? 0 : FUTEX_PRIVATE_FLAG);
|
|
#else
|
|
rwlock->__data.__shared = (iattr->pshared == PTHREAD_PROCESS_PRIVATE
|
|
? 0
|
|
: THREAD_GETMEM (THREAD_SELF,
|
|
header.private_futex));
|
|
#endif
|
|
|
|
rwlock->__data.__pad1 = 0;
|
|
rwlock->__data.__pad2 = 0;
|
|
|
|
return 0;
|
|
}
|
|
strong_alias (__pthread_rwlock_init, pthread_rwlock_init)
|