Use custom allocators for embedded usage¶
Manage memory allocator functions
SYNOPSIS¶
- #include <libmemcached/memcached.h>
Compile and link with -lmemcached
-
memcached_return_t
memcached_set_memory_allocators
(memcached_st *ptr, memcached_malloc_fn mem_malloc, memcached_free_fn mem_free, memcached_realloc_fn mem_realloc, memcached_calloc_fn mem_calloc, void *context)¶ - Parameters
ptr -- pointer to an initialized
memcached_st
structmem_malloc -- pointer to a
memcached_malloc_fn
callbackmem_free -- pointer to a
memcached_free_fn
callbackmem_realloc -- pointer to a
memcached_realloc_fn
callbackmem_calloc -- pointer to a
memcached_calloc_fn
callbackcontext -- pointer to a user supplied context
- Returns
memcached_return_t
indicating success
-
void
memcached_get_memory_allocators
(memcached_st *ptr, memcached_malloc_fn *mem_malloc, memcached_free_fn *mem_free, memcached_realloc_fn *mem_realloc, memcached_calloc_fn *mem_calloc)¶ - Parameters
ptr -- pointer to an initialized
memcached_st
structmem_malloc -- pointer to store the address of the
memcached_malloc_fn
callbackmem_free -- pointer to store the address of the
memcached_free_fn
callbackmem_realloc -- pointer to store the address of the
memcached_realloc_fn
callbackmem_calloc -- pointer to store the address of the
memcached_calloc_fn
callback
-
void *
memcached_get_memory_allocators_context
(const memcached_st *ptr)¶ - Parameters
ptr -- pointer to an initialized
memcached_st
struct- Returns
pointer to the user supplied context
-
typedef void *(*
memcached_malloc_fn
)(memcached_st *ptr, const size_t size, void *context)¶ - Parameters
ptr -- pointer to an initialized
memcached_st
structsize -- the number of bytes to allocate
context -- pointer to the user supplied context
- Returns
pointer to at least
size
bytes of allocated memory
-
typedef void *(*
memcached_realloc_fn
)(memcached_st *ptr, void *mem, const size_t size, void *context)¶ - Parameters
ptr -- pointer to an initialized
memcached_st
structmem -- pointer to previously allocated memory
size -- the number of bytes to allocate
context -- pointer to the user supplied context
- Returns
pointer to at least
size
bytes of allocated memory
-
typedef void (*
memcached_free_fn
)(memcached_st *ptr, void *mem, void *context)¶ - Parameters
ptr -- pointer to an initialized
memcached_st
structmem -- pointer to previously allocated memory
context -- pointer to the user supplied context
-
typedef void *(*
memcached_calloc_fn
)(memcached_st *ptr, size_t nelem, const size_t elsize, void *context)¶ - Parameters
ptr -- pointer to an initialized
memcached_st
structnelem -- number of elements to allocate
elsize -- the number of bytes to allocate per element
context -- pointer to the user supplied context
- Returns
pointer to at least
elsize
*nelem
bytes of allocated and zeroed memory
DESCRIPTION¶
libmemcached
allows you to specify your own memory allocators, optimized for
your application. This enables libmemcached to be used inside of applications
that have their own malloc implementation.
memcached_set_memory_allocators()
is used to set the memory allocators
used by the memcached instance specified by ptr. Please note that you cannot
override only one of the memory allocators, you have to specify a complete new
set if you want to override one of them. All of the memory allocation functions
should behave as specified in the C99 standard. Specify NULL as all functions to
reset them to the default values.
memcached_get_memory_allocators()
is used to get the currently used memory
allocators by a memcached handle.
memcached_get_memory_allocators_context()
returns the void * that was
passed in during the call to memcached_set_memory_allocators()
.
The first argument to the memory allocator functions is a pointer to a memcached structure, the is passed as const and you will need to clone it in order to make use of any operation which would modify it.
NOTES¶
In version 0.38 all functions were modified to have a context void pointer passed to them. This was so that custom allocators could have their own space for memory.
RETURN VALUE¶
memcached_set_memory_allocators()
returns MEMCACHED_SUCCESS
upon success,
and MEMCACHED_FAILURE
if you don't pass a complete set of function pointers.