service_thd_alloc.h File Reference

This service provides functions to allocate memory in a connection local memory pool. More...

#include <stdlib.h>
#include <mysql/mysql_lex_string.h>

Go to the source code of this file.

Classes
struct	thd_alloc_service_st

Macros
#define	MYSQL_THD   THD *
#define	MYSQL_SERVICE_THD_ALLOC_INCLUDED

Functions
void *	thd_alloc (MYSQL_THD thd, size_t size)
	Allocate memory in the connection's local memory pool. More...
void *	thd_calloc (MYSQL_THD thd, size_t size)
char *	thd_strdup (MYSQL_THD thd, const char *str)
char *	thd_strmake (MYSQL_THD thd, const char *str, size_t size)
void *	thd_memdup (MYSQL_THD thd, const void *str, size_t size)
MYSQL_LEX_STRING *	thd_make_lex_string (MYSQL_THD thd, MYSQL_LEX_STRING *lex_str, const char *str, size_t size, int allocate_lex_string)
	Create a LEX_STRING in this connection's local memory pool. More...

Variables
struct thd_alloc_service_st *	thd_alloc_service

Detailed Description

This service provides functions to allocate memory in a connection local memory pool.

The memory allocated there will be automatically freed at the end of the statement, don't use it for allocations that should live longer than that. For short living allocations this is more efficient than using my_malloc and friends, and automatic "garbage collection" allows not to think about memory leaks.

The pool is best for small to medium objects, don't use it for large allocations - they are better served with my_malloc.

Macro Definition Documentation

MYSQL_SERVICE_THD_ALLOC_INCLUDED

#define MYSQL_SERVICE_THD_ALLOC_INCLUDED

MYSQL_THD

#define MYSQL_THD   THD *

Function Documentation

thd_alloc()

void * thd_alloc	(	MYSQL_THD	thd,
		size_t	size
	)

Allocate memory in the connection's local memory pool.

When properly used in place of my_malloc(), this can significantly improve concurrency. Don't use this or related functions to allocate large chunks of memory. Use for temporary storage only. The memory will be freed automatically at the end of the statement; no explicit code is required to prevent memory leaks.

See also

alloc_root()

thd_calloc()

void * thd_calloc	(	MYSQL_THD	thd,
		size_t	size
	)

See also

thd_alloc()

thd_make_lex_string()

MYSQL_LEX_STRING * thd_make_lex_string	(	MYSQL_THD	thd,
		MYSQL_LEX_STRING *	lex_str,
		const char *	str,
		size_t	size,
		int	allocate_lex_string
	)

Create a LEX_STRING in this connection's local memory pool.

Parameters

thd	user thread connection handle
lex_str	pointer to LEX_STRING object to be initialized
str	initializer to be copied into lex_str
size	length of str, in bytes
allocate_lex_string	flag: if TRUE, allocate new LEX_STRING object, instead of using lex_str value

Returns

NULL on failure, or pointer to the LEX_STRING object

See also

thd_alloc()

thd_memdup()

void * thd_memdup	(	MYSQL_THD	thd,
		const void *	str,
		size_t	size
	)

See also

thd_alloc()

thd_strdup()

char * thd_strdup	(	MYSQL_THD	thd,
		const char *	str
	)

See also

thd_alloc()

thd_strmake()

char * thd_strmake	(	MYSQL_THD	thd,
		const char *	str,
		size_t	size
	)

See also

thd_alloc()

Variable Documentation

thd_alloc_service

struct thd_alloc_service_st * thd_alloc_service