Commit 8360e1a5 authored by Sergei Golubchik's avatar Sergei Golubchik

MDEV-6712 THD specifics for plugins

thd_specifics service
parent 0c7d773f
......@@ -185,6 +185,18 @@ void thd_inc_error_row(void* thd);
char *thd_get_error_context_description(void* thd,
char *buffer, unsigned int length,
unsigned int max_query_length);
#include <mysql/service_thd_specifics.h>
typedef int MYSQL_THD_KEY_T;
extern struct thd_specifics_service_st {
int (*thd_key_create_func)(MYSQL_THD_KEY_T *key);
void (*thd_key_delete_func)(MYSQL_THD_KEY_T *key);
void *(*thd_getspecific_func)(void* thd, MYSQL_THD_KEY_T key);
int (*thd_setspecific_func)(void* thd, MYSQL_THD_KEY_T key, void *value);
} *thd_specifics_service;
int thd_key_create(MYSQL_THD_KEY_T *key);
void thd_key_delete(MYSQL_THD_KEY_T *key);
void* thd_getspecific(void* thd, MYSQL_THD_KEY_T key);
int thd_setspecific(void* thd, MYSQL_THD_KEY_T key, void *value);
struct st_mysql_xid {
long formatID;
long gtrid_length;
......
......@@ -185,6 +185,18 @@ void thd_inc_error_row(void* thd);
char *thd_get_error_context_description(void* thd,
char *buffer, unsigned int length,
unsigned int max_query_length);
#include <mysql/service_thd_specifics.h>
typedef int MYSQL_THD_KEY_T;
extern struct thd_specifics_service_st {
int (*thd_key_create_func)(MYSQL_THD_KEY_T *key);
void (*thd_key_delete_func)(MYSQL_THD_KEY_T *key);
void *(*thd_getspecific_func)(void* thd, MYSQL_THD_KEY_T key);
int (*thd_setspecific_func)(void* thd, MYSQL_THD_KEY_T key, void *value);
} *thd_specifics_service;
int thd_key_create(MYSQL_THD_KEY_T *key);
void thd_key_delete(MYSQL_THD_KEY_T *key);
void* thd_getspecific(void* thd, MYSQL_THD_KEY_T key);
int thd_setspecific(void* thd, MYSQL_THD_KEY_T key, void *value);
struct st_mysql_xid {
long formatID;
long gtrid_length;
......
......@@ -185,6 +185,18 @@ void thd_inc_error_row(void* thd);
char *thd_get_error_context_description(void* thd,
char *buffer, unsigned int length,
unsigned int max_query_length);
#include <mysql/service_thd_specifics.h>
typedef int MYSQL_THD_KEY_T;
extern struct thd_specifics_service_st {
int (*thd_key_create_func)(MYSQL_THD_KEY_T *key);
void (*thd_key_delete_func)(MYSQL_THD_KEY_T *key);
void *(*thd_getspecific_func)(void* thd, MYSQL_THD_KEY_T key);
int (*thd_setspecific_func)(void* thd, MYSQL_THD_KEY_T key, void *value);
} *thd_specifics_service;
int thd_key_create(MYSQL_THD_KEY_T *key);
void thd_key_delete(MYSQL_THD_KEY_T *key);
void* thd_getspecific(void* thd, MYSQL_THD_KEY_T key);
int thd_setspecific(void* thd, MYSQL_THD_KEY_T key, void *value);
struct st_mysql_xid {
long formatID;
long gtrid_length;
......
......@@ -185,6 +185,18 @@ void thd_inc_error_row(void* thd);
char *thd_get_error_context_description(void* thd,
char *buffer, unsigned int length,
unsigned int max_query_length);
#include <mysql/service_thd_specifics.h>
typedef int MYSQL_THD_KEY_T;
extern struct thd_specifics_service_st {
int (*thd_key_create_func)(MYSQL_THD_KEY_T *key);
void (*thd_key_delete_func)(MYSQL_THD_KEY_T *key);
void *(*thd_getspecific_func)(void* thd, MYSQL_THD_KEY_T key);
int (*thd_setspecific_func)(void* thd, MYSQL_THD_KEY_T key, void *value);
} *thd_specifics_service;
int thd_key_create(MYSQL_THD_KEY_T *key);
void thd_key_delete(MYSQL_THD_KEY_T *key);
void* thd_getspecific(void* thd, MYSQL_THD_KEY_T key);
int thd_setspecific(void* thd, MYSQL_THD_KEY_T key, void *value);
struct st_mysql_xid {
long formatID;
long gtrid_length;
......
#ifndef MYSQL_SERVICE_THD_SPECIFICS_INCLUDED
/* Copyright (c) 2009, 2010, 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 as published by
the Free Software Foundation; version 2 of the License.
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 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
THD specific for plugin(s)
This API provides pthread_getspecific like functionality to plugin authors.
This is a functional alternative to the declarative MYSQL_THDVAR
A plugin should at init call thd_key_create that create a key that
will have storage in each THD. The key should be used by all threads
and can be used concurrently from all threads.
A plugin should at deinit call thd_key_delete.
Alternatively, a plugin can use thd_key_create_from_var(K,V) to create
a key that corresponds to a named MYSQL_THDVAR variable.
This API is also safe when using pool-of-threads in which case
pthread_getspecific is not, because the actual OS thread may change.
@note
Normally one should prefer MYSQL_THDVAR declarative API.
The benefits are:
- It supports typed variables (int, char*, enum, etc), not only void*.
- The memory allocated for MYSQL_THDVAR is free'd automatically
(if PLUGIN_VAR_MEMALLOC is specified).
- Continuous loading and unloading of the same plugin does not allocate
memory for same variables over and over again.
An example of using MYSQL_THDVAR for a thd local storage:
MYSQL_THDVAR_STR(my_tls,
PLUGIN_VAR_MEMALLOC | PLUGIN_VAR_NOSYSVAR | PLUGIN_VAR_NOCMDOPT,
"thd local storage example", 0, 0, 0);
*/
#ifdef __cplusplus
extern "C" {
#endif
typedef int MYSQL_THD_KEY_T;
extern struct thd_specifics_service_st {
int (*thd_key_create_func)(MYSQL_THD_KEY_T *key);
void (*thd_key_delete_func)(MYSQL_THD_KEY_T *key);
void *(*thd_getspecific_func)(MYSQL_THD thd, MYSQL_THD_KEY_T key);
int (*thd_setspecific_func)(MYSQL_THD thd, MYSQL_THD_KEY_T key, void *value);
} *thd_specifics_service;
#define thd_key_create_from_var(K, V) do { *(K)= MYSQL_SYSVAR_NAME(V).offset; } while(0)
#ifdef MYSQL_DYNAMIC_PLUGIN
#define thd_key_create(K) (thd_specifics_service->thd_key_create_func(K))
#define thd_key_delete(K) (thd_specifics_service->thd_key_delete_func(K))
#define thd_getspecific(T, K) (thd_specifics_service->thd_getspecific_func(T, K))
#define thd_setspecific(T, K, V) (thd_specifics_service->thd_setspecific_func(T, K, V))
#else
/**
* create THD specific storage
* @return 0 on success
* else errno is returned
*/
int thd_key_create(MYSQL_THD_KEY_T *key);
/**
* delete THD specific storage
*/
void thd_key_delete(MYSQL_THD_KEY_T *key);
/**
* get/set thd specific storage
* - first time this is called from a thread it will return 0
* - this call is thread-safe in that different threads may call this
* simultaneously if operating on different THDs.
* - this call acquires no mutexes and is implemented as an array lookup
*/
void* thd_getspecific(MYSQL_THD thd, MYSQL_THD_KEY_T key);
int thd_setspecific(MYSQL_THD thd, MYSQL_THD_KEY_T key, void *value);
#endif
#ifdef __cplusplus
}
#endif
#define MYSQL_SERVICE_THD_SPECIFICS_INCLUDED
#endif
......@@ -31,6 +31,7 @@ extern "C" {
#include <mysql/service_logger.h>
#include <mysql/service_thd_autoinc.h>
#include <mysql/service_thd_error_context.h>
#include <mysql/service_thd_specifics.h>
/*#include <mysql/service_wsrep.h>*/
#ifdef __cplusplus
......
......@@ -34,3 +34,5 @@
#define VERSION_logger 0x0100
#define VERSION_thd_autoinc 0x0100
#define VERSION_thd_error_context 0x0100
#define VERSION_thd_specifics 0x0100
......@@ -22,6 +22,7 @@ SET(MYSQLSERVICES_SOURCES
thd_timezone_service.c
thd_autoinc_service.c
thd_error_context_service.c
thd_specifics_service.c
progress_report_service.c
debug_sync_service.c
my_sha1_service.c
......
/* Copyright (C) 2014 MariaDB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
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 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 */
#include <service_versions.h>
SERVICE_VERSION thd_specifics_service= (void *) VERSION_thd_specifics;
......@@ -4094,3 +4094,51 @@ static void restore_ptr_backup(uint n, st_ptr_backup *backup)
(backup++)->restore();
}
/****************************************************************************
thd specifics service, see include/mysql/service_thd_specifics.h
****************************************************************************/
static const int INVALID_THD_KEY= -1;
static uint thd_key_no = 42;
int thd_key_create(MYSQL_THD_KEY_T *key)
{
int flags= PLUGIN_VAR_THDLOCAL | PLUGIN_VAR_STR |
PLUGIN_VAR_NOSYSVAR | PLUGIN_VAR_NOCMDOPT;
char namebuf[256];
snprintf(namebuf, sizeof(namebuf), "%u", thd_key_no++);
mysql_rwlock_wrlock(&LOCK_system_variables_hash);
// non-letters in the name as an extra safety
st_bookmark *bookmark= register_var("\a\v\a\t\a\r", namebuf, flags);
mysql_rwlock_unlock(&LOCK_system_variables_hash);
if (bookmark)
{
*key= bookmark->offset;
return 0;
}
return ENOMEM;
}
void thd_key_delete(MYSQL_THD_KEY_T *key)
{
*key= INVALID_THD_KEY;
}
void* thd_getspecific(MYSQL_THD thd, MYSQL_THD_KEY_T key)
{
DBUG_ASSERT(key != INVALID_THD_KEY);
if (key == INVALID_THD_KEY || (!thd && !(thd= current_thd)))
return 0;
return *(void**)(intern_sys_var_ptr(thd, key, true));
}
int thd_setspecific(MYSQL_THD thd, MYSQL_THD_KEY_T key, void *value)
{
DBUG_ASSERT(key != INVALID_THD_KEY);
if (key == INVALID_THD_KEY || (!thd && !(thd= current_thd)))
return EINVAL;
memcpy(intern_sys_var_ptr(thd, key, true), &value, sizeof(void*));
return 0;
}
......@@ -139,6 +139,14 @@ static struct wsrep_service_st wsrep_handler = {
wsrep_unlock_rollback
};
static struct thd_specifics_service_st thd_specifics_handler=
{
thd_key_create,
thd_key_delete,
thd_getspecific,
thd_setspecific
};
static struct st_service_ref list_of_services[]=
{
{ "my_snprintf_service", VERSION_my_snprintf, &my_snprintf_handler },
......@@ -153,6 +161,7 @@ static struct st_service_ref list_of_services[]=
{ "logger_service", VERSION_logger, &logger_service_handler },
{ "thd_autoinc_service", VERSION_thd_autoinc, &thd_autoinc_handler },
{ "wsrep_service", VERSION_wsrep, &wsrep_handler },
{ "thd_specifics_service", VERSION_thd_specifics, &thd_specifics_handler },
{ "thd_error_context_service", VERSION_thd_error_context, &thd_error_conext_handler },
};
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