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#ifndef THR_MUTEX_INCLUDED
#define THR_MUTEX_INCLUDED
/* Copyright (c) 2014, 2019, 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_mutex.h
MySQL mutex implementation.
There are three "layers":
1) native_mutex_*()
Functions that map directly down to OS primitives.
Windows - CriticalSection
Other OSes - pthread
2) my_mutex_*()
Functions that implement SAFE_MUTEX (default for debug),
Otherwise native_mutex_*() is used.
3) mysql_mutex_*()
Functions that include Performance Schema instrumentation.
See include/mysql/psi/mysql_thread.h
*/
#include <stddef.h>
#include <sys/types.h>
#include "my_dbug.h"
#include "my_inttypes.h"
#include "my_macros.h"
#include "my_thread.h"
/*
The following are part of the services ABI:
- native_mutex_t
- my_mutex_t
*/
#include "mysql/components/services/thr_mutex_bits.h"
/* Define mutex types, see my_thr_init.c */
#define MY_MUTEX_INIT_SLOW NULL
/* Can be set in /usr/include/pthread.h */
#ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
extern native_mutexattr_t my_fast_mutexattr;
#define MY_MUTEX_INIT_FAST &my_fast_mutexattr
#else
#define MY_MUTEX_INIT_FAST NULL
#endif
/* Can be set in /usr/include/pthread.h */
#ifdef PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
extern native_mutexattr_t my_errorcheck_mutexattr;
#define MY_MUTEX_INIT_ERRCHK &my_errorcheck_mutexattr
#else
#define MY_MUTEX_INIT_ERRCHK NULL
#endif
static inline int native_mutex_init(native_mutex_t *mutex,
const native_mutexattr_t *attr
MY_ATTRIBUTE((unused))) {
#ifdef _WIN32
InitializeCriticalSection(mutex);
return 0;
#else
return pthread_mutex_init(mutex, attr);
#endif
}
static inline int native_mutex_lock(native_mutex_t *mutex) {
#ifdef _WIN32
EnterCriticalSection(mutex);
return 0;
#else
return pthread_mutex_lock(mutex);
#endif
}
static inline int native_mutex_trylock(native_mutex_t *mutex) {
#ifdef _WIN32
if (TryEnterCriticalSection(mutex)) {
/* Don't allow recursive lock */
if (mutex->RecursionCount > 1) {
LeaveCriticalSection(mutex);
return EBUSY;
}
return 0;
}
return EBUSY;
#else
return pthread_mutex_trylock(mutex);
#endif
}
static inline int native_mutex_unlock(native_mutex_t *mutex) {
#ifdef _WIN32
LeaveCriticalSection(mutex);
return 0;
#else
return pthread_mutex_unlock(mutex);
#endif
}
static inline int native_mutex_destroy(native_mutex_t *mutex) {
#ifdef _WIN32
DeleteCriticalSection(mutex);
return 0;
#else
return pthread_mutex_destroy(mutex);
#endif
}
#ifdef SAFE_MUTEX
/* safe_mutex adds checking to mutex for easier debugging */
struct safe_mutex_t {
native_mutex_t global, mutex;
const char *file;
uint line, count;
my_thread_t thread;
};
void safe_mutex_global_init();
int safe_mutex_init(safe_mutex_t *mp, const native_mutexattr_t *attr,
const char *file, uint line);
int safe_mutex_lock(safe_mutex_t *mp, bool try_lock, const char *file,
uint line);
int safe_mutex_unlock(safe_mutex_t *mp, const char *file, uint line);
int safe_mutex_destroy(safe_mutex_t *mp, const char *file, uint line);
static inline void safe_mutex_assert_owner(safe_mutex_t *mp) {
DBUG_ASSERT(mp != NULL);
native_mutex_lock(&mp->global);
DBUG_ASSERT(mp->count > 0 && my_thread_equal(my_thread_self(), mp->thread));
native_mutex_unlock(&mp->global);
}
static inline void safe_mutex_assert_not_owner(safe_mutex_t *mp) {
DBUG_ASSERT(mp != NULL);
native_mutex_lock(&mp->global);
DBUG_ASSERT(!mp->count || !my_thread_equal(my_thread_self(), mp->thread));
native_mutex_unlock(&mp->global);
}
#endif /* SAFE_MUTEX */
static inline int my_mutex_init(my_mutex_t *mp, const native_mutexattr_t *attr
#ifdef SAFE_MUTEX
,
const char *file, uint line
#endif
) {
#ifdef SAFE_MUTEX
DBUG_ASSERT(mp != NULL);
mp->m_u.m_safe_ptr = (safe_mutex_t *)malloc(sizeof(safe_mutex_t));
return safe_mutex_init(mp->m_u.m_safe_ptr, attr, file, line);
#else
return native_mutex_init(&mp->m_u.m_native, attr);
#endif
}
static inline int my_mutex_lock(my_mutex_t *mp
#ifdef SAFE_MUTEX
,
const char *file, uint line
#endif
) {
#ifdef SAFE_MUTEX
DBUG_ASSERT(mp != NULL);
DBUG_ASSERT(mp->m_u.m_safe_ptr != NULL);
return safe_mutex_lock(mp->m_u.m_safe_ptr, false, file, line);
#else
return native_mutex_lock(&mp->m_u.m_native);
#endif
}
static inline int my_mutex_trylock(my_mutex_t *mp
#ifdef SAFE_MUTEX
,
const char *file, uint line
#endif
) {
#ifdef SAFE_MUTEX
DBUG_ASSERT(mp != NULL);
DBUG_ASSERT(mp->m_u.m_safe_ptr != NULL);
return safe_mutex_lock(mp->m_u.m_safe_ptr, true, file, line);
#else
return native_mutex_trylock(&mp->m_u.m_native);
#endif
}
static inline int my_mutex_unlock(my_mutex_t *mp
#ifdef SAFE_MUTEX
,
const char *file, uint line
#endif
) {
#ifdef SAFE_MUTEX
DBUG_ASSERT(mp != NULL);
DBUG_ASSERT(mp->m_u.m_safe_ptr != NULL);
return safe_mutex_unlock(mp->m_u.m_safe_ptr, file, line);
#else
return native_mutex_unlock(&mp->m_u.m_native);
#endif
}
static inline int my_mutex_destroy(my_mutex_t *mp
#ifdef SAFE_MUTEX
,
const char *file, uint line
#endif
) {
#ifdef SAFE_MUTEX
DBUG_ASSERT(mp != NULL);
DBUG_ASSERT(mp->m_u.m_safe_ptr != NULL);
int rc = safe_mutex_destroy(mp->m_u.m_safe_ptr, file, line);
free(mp->m_u.m_safe_ptr);
mp->m_u.m_safe_ptr = NULL;
return rc;
#else
return native_mutex_destroy(&mp->m_u.m_native);
#endif
}
#endif /* THR_MUTEX_INCLUDED */
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