You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
148 lines
4.2 KiB
148 lines
4.2 KiB
#ifndef THR_RWLOCK_INCLUDED
|
|
#define THR_RWLOCK_INCLUDED
|
|
|
|
/* Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License, version 2.0,
|
|
as published by the Free Software Foundation.
|
|
|
|
This program is also distributed with certain software (including
|
|
but not limited to OpenSSL) that is licensed under separate terms,
|
|
as designated in a particular file or component or in included license
|
|
documentation. The authors of MySQL hereby grant you an additional
|
|
permission to link the program and your derivative works with the
|
|
separately licensed software that they have included with MySQL.
|
|
|
|
This program 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 General Public License, version 2.0, for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
|
|
|
|
/**
|
|
@file include/thr_rwlock.h
|
|
MySQL rwlock implementation.
|
|
|
|
There are two "layers":
|
|
1) native_rw_*()
|
|
Functions that map directly down to OS primitives.
|
|
Windows - SRWLock
|
|
Other OSes - pthread
|
|
2) mysql_rw*()
|
|
Functions that include Performance Schema instrumentation.
|
|
See include/mysql/psi/mysql_thread.h
|
|
|
|
This file also includes rw_pr_*(), which implements a special
|
|
version of rwlocks that prefer readers. The P_S version of these
|
|
are mysql_prlock_*() - see include/mysql/psi/mysql_thread.h
|
|
*/
|
|
|
|
#include <stddef.h>
|
|
#include <sys/types.h>
|
|
#ifdef _WIN32
|
|
#include <windows.h>
|
|
#endif
|
|
|
|
#include "my_dbug.h"
|
|
#include "my_inttypes.h"
|
|
#include "my_macros.h"
|
|
#include "my_thread.h"
|
|
#include "mysql/components/services/thr_rwlock_bits.h"
|
|
#include "thr_cond.h"
|
|
#include "thr_mutex.h"
|
|
|
|
static inline int native_rw_init(native_rw_lock_t *rwp) {
|
|
#ifdef _WIN32
|
|
InitializeSRWLock(&rwp->srwlock);
|
|
rwp->have_exclusive_srwlock = false;
|
|
return 0;
|
|
#else
|
|
/* pthread_rwlockattr_t is not used in MySQL */
|
|
return pthread_rwlock_init(rwp, NULL);
|
|
#endif
|
|
}
|
|
|
|
static inline int native_rw_destroy(
|
|
native_rw_lock_t *rwp MY_ATTRIBUTE((unused))) {
|
|
#ifdef _WIN32
|
|
return 0; /* no destroy function */
|
|
#else
|
|
return pthread_rwlock_destroy(rwp);
|
|
#endif
|
|
}
|
|
|
|
static inline int native_rw_rdlock(native_rw_lock_t *rwp) {
|
|
#ifdef _WIN32
|
|
AcquireSRWLockShared(&rwp->srwlock);
|
|
return 0;
|
|
#else
|
|
return pthread_rwlock_rdlock(rwp);
|
|
#endif
|
|
}
|
|
|
|
static inline int native_rw_tryrdlock(native_rw_lock_t *rwp) {
|
|
#ifdef _WIN32
|
|
if (!TryAcquireSRWLockShared(&rwp->srwlock)) return EBUSY;
|
|
return 0;
|
|
#else
|
|
return pthread_rwlock_tryrdlock(rwp);
|
|
#endif
|
|
}
|
|
|
|
static inline int native_rw_wrlock(native_rw_lock_t *rwp) {
|
|
#ifdef _WIN32
|
|
AcquireSRWLockExclusive(&rwp->srwlock);
|
|
rwp->have_exclusive_srwlock = true;
|
|
return 0;
|
|
#else
|
|
return pthread_rwlock_wrlock(rwp);
|
|
#endif
|
|
}
|
|
|
|
static inline int native_rw_trywrlock(native_rw_lock_t *rwp) {
|
|
#ifdef _WIN32
|
|
if (!TryAcquireSRWLockExclusive(&rwp->srwlock)) return EBUSY;
|
|
rwp->have_exclusive_srwlock = true;
|
|
return 0;
|
|
#else
|
|
return pthread_rwlock_trywrlock(rwp);
|
|
#endif
|
|
}
|
|
|
|
static inline int native_rw_unlock(native_rw_lock_t *rwp) {
|
|
#ifdef _WIN32
|
|
if (rwp->have_exclusive_srwlock) {
|
|
rwp->have_exclusive_srwlock = false;
|
|
ReleaseSRWLockExclusive(&rwp->srwlock);
|
|
} else
|
|
ReleaseSRWLockShared(&rwp->srwlock);
|
|
return 0;
|
|
#else
|
|
return pthread_rwlock_unlock(rwp);
|
|
#endif
|
|
}
|
|
|
|
extern int rw_pr_init(rw_pr_lock_t *);
|
|
extern int rw_pr_rdlock(rw_pr_lock_t *);
|
|
extern int rw_pr_wrlock(rw_pr_lock_t *);
|
|
extern int rw_pr_unlock(rw_pr_lock_t *);
|
|
extern int rw_pr_destroy(rw_pr_lock_t *);
|
|
|
|
#ifdef SAFE_MUTEX
|
|
static inline void rw_pr_lock_assert_write_owner(const rw_pr_lock_t *rwlock) {
|
|
DBUG_ASSERT(rwlock->active_writer &&
|
|
my_thread_equal(my_thread_self(), rwlock->writer_thread));
|
|
}
|
|
|
|
static inline void rw_pr_lock_assert_not_write_owner(
|
|
const rw_pr_lock_t *rwlock) {
|
|
DBUG_ASSERT(!rwlock->active_writer ||
|
|
!my_thread_equal(my_thread_self(), rwlock->writer_thread));
|
|
}
|
|
#endif
|
|
|
|
#endif /* THR_RWLOCK_INCLUDED */
|
|
|