Working with memcached pools


#include <libmemcached/memcached_pool.h>

memcached_pool_st* memcached_pool(const char *option_string, size_t option_string_length)
memcached_pool_st* memcached_pool_create(memcached_st* mmc, int initial, int max)

Deprecated since version 0.46: Use memcached_pool()

memcached_st* memcached_pool_destroy(memcached_pool_st* pool)
memcached_st* memcached_pool_pop(memcached_pool_st* pool, bool block, memcached_return_t *rc)

Deprecated since version 0.53: Use memcached_pool_fetch()

memcached_st* memcached_pool_fetch(memcached_pool_st*, struct timespec* relative_time, memcached_return_t* rc)

New in version 0.53: Synonym for memcached_pool_pop

memcached_return_t memcached_pool_push(memcached_pool_st* pool, memcached_st *mmc)

Deprecated since version 0.53: Use memcached_pool_push()

memcached_return_t memcached_pool_release(memcached_pool_st* pool, memcached_st* mmc)

New in version 0.53: Synonym for memcached_pool_push.

memcached_return_t memcached_pool_behavior_set(memcached_pool_st *pool, memcached_behavior_t flag, uint64_t data)
memcached_return_t memcached_pool_behavior_get(memcached_pool_st *pool, memcached_behavior_t flag, uint64_t *value)

Compile and link with -lmemcachedutil -lmemcached


memcached_pool() is used to create a connection pool of objects you may use to remove the overhead of using memcached_clone for short lived memcached_st objects. Please see Configuring Libmemcached for details on the format of the configuration string.

memcached_pool_destroy() is used to destroy the connection pool created with memcached_pool_create() and release all allocated resources. It will return the pointer to the memcached_st structure passed as an argument to memcached_pool_create(), and returns the ownership of the pointer to the caller when created with memcached_pool_create(), otherwise NULL is returned..

memcached_pool_fetch() is used to fetch a connection structure from the connection pool. The relative_time argument specifies if the function should block and wait for a connection structure to be available if we try to exceed the maximum size. You need to specify time in relative time.

memcached_pool_release() is used to return a connection structure back to the pool.

memcached_pool_behavior_get() and memcached_pool_behavior_set() is used to get/set behavior flags on all connections in the pool.

Both memcached_pool_release() and memcached_pool_fetch() are thread safe.


memcached_pool_destroy() returns the pointer (and ownership) to the memcached_st structure used to create the pool. If connections are in use it returns NULL.

memcached_pool_pop() returns a pointer to a memcached_st structure from the pool (or NULL if an allocation cannot be satisfied).

memcached_pool_release() returns MEMCACHED_SUCCESS upon success.

memcached_pool_behavior_get() and memcached_pool_behavior_get() returns MEMCACHED_SUCCESS upon success.

If any methods returns MEMCACHED_IN_PROGRESS then a lock on the pool could not be obtained. If any of the parameters passed to any of these functions is invalid, MEMCACHED_INVALID_ARGUMENTS will be returned.

memcached_pool_fetch may return MEMCACHED_TIMEOUT if a timeout occurs while waiting for a free memcached_st. MEMCACHED_NOTFOUND if no memcached_st was available.


To find out more information please check:


Brian Aker, <>

Trond Norbye, <>


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

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