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MEMCACHED_MEMORY_ALLOCATORS(3) libmemcached-awesome MEMCACHED_MEMORY_ALLOCATORS(3)

memcached_memory_allocators - libmemcached Documentation

Manage memory allocator functions

#include <libmemcached/memcached.h>
Compile and link with -lmemcached

  • ptr -- pointer to an initialized memcached_st struct
  • mem_malloc -- pointer to a memcached_malloc_fn callback
  • mem_free -- pointer to a memcached_free_fn callback
  • mem_realloc -- pointer to a memcached_realloc_fn callback
  • mem_calloc -- pointer to a memcached_calloc_fn callback
  • context -- pointer to a user supplied context

memcached_return_t indicating success


  • ptr -- pointer to an initialized memcached_st struct
  • mem_malloc -- pointer to store the address of the memcached_malloc_fn callback
  • mem_free -- pointer to store the address of the memcached_free_fn callback
  • mem_realloc -- pointer to store the address of the memcached_realloc_fn callback
  • mem_calloc -- pointer to store the address of the memcached_calloc_fn callback



ptr -- pointer to an initialized memcached_st struct
pointer to the user supplied context


pointer to an initialized memcached_st struct
the number of bytes to allocate
pointer to the user supplied context
pointer to at least size bytes of allocated memory


pointer to an initialized memcached_st struct
pointer to previously allocated memory
the number of bytes to allocate
pointer to the user supplied context
pointer to at least size bytes of allocated memory


pointer to an initialized memcached_st struct
pointer to previously allocated memory
pointer to the user supplied context


pointer to an initialized memcached_st struct
number of elements to allocate
the number of bytes to allocate per element
pointer to the user supplied context
pointer to at least elsize * nelem bytes of allocated and zeroed memory


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.

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.

memcached_set_memory_allocators() returns MEMCACHED_SUCCESS upon success, and MEMCACHED_FAILURE if you don't pass a complete set of function pointers.

memcached(1) libmemcached(3) memcached_strerror(3)

March 6, 2023 1.1