/*
* Copyright (C) Igor Sysoev
* Copyright (C) NGINX, Inc.
*/
#ifndef _NXT_MP_H_INCLUDED_
#define _NXT_MP_H_INCLUDED_
/*
* Memory pool keeps track of all allocations so they can be freed at once
* on pool destruction. A memory pool is not thread safe, so only one thread
* must work with the pool. If an allocation should be passed to another
* thread, it should be allocated with nxt_mp_retain() and then should be
* freed with nxt_mp_release(). These functions updates pool retention
* counter. Memory pools decrease number of malloc() and free() calls and
* thus reduces thread contention on locks in malloc library. Memory pools
* allow to make both freeable and non-freeable allocations. The freeable
* memory is allocated in fixed size chunks to decrease memory fragmentaiton
* on reallocations. The non-freeable memory is intended to allocate
* structures and other items which should be available until memory pool
* destruction. Due to allocation strategy described in nxt_mp.c memory pools
* may also improve data cache locality.
*/
typedef struct nxt_mp_s nxt_mp_t;
/*
* nxt_mp_create() creates a memory pool and sets the pool's retention
* counter to 1.
*/
NXT_EXPORT nxt_mp_t *nxt_mp_create(size_t cluster_size, size_t page_alignment,
size_t page_size, size_t min_chunk_size)
NXT_MALLOC_LIKE;
/*
* nxt_mp_destroy() destroys memory pool in spite of the pool's retention
* counter.
*/
NXT_EXPORT void nxt_mp_destroy(nxt_mp_t *mp);
/* nxt_mp_test_sizes() tests validity of memory pool parameters. */
NXT_EXPORT nxt_bool_t nxt_mp_test_sizes(size_t cluster_size,
size_t page_alignment, size_t page_size, size_t min_chunk_size);
/* nxt_mp_is_empty() tests that pool is empty. */
NXT_EXPORT nxt_bool_t nxt_mp_is_empty(nxt_mp_t *mp);
/*
* nxt_mp_alloc() returns aligned freeable memory.
* The alignment is sutiable to allocate structures.
*/
NXT_EXPORT void *nxt_mp_alloc(nxt_mp_t *mp, size_t size)
NXT_MALLOC_LIKE;
/*
* nxt_mp_zalloc() returns zeroed aligned freeable memory.
* The alignment is sutiable to allocate structures.
*/
NXT_EXPORT void *nxt_mp_zalloc(nxt_mp_t *mp, size_t size)
NXT_MALLOC_LIKE;
/* nxt_mp_align() returns aligned freeable memory. */
NXT_EXPORT void *nxt_mp_align(nxt_mp_t *mp, size_t alignment, size_t size)
NXT_MALLOC_LIKE;
/* nxt_mp_zalign() returns zeroed aligned freeable memory. */
NXT_EXPORT void *nxt_mp_zalign(nxt_mp_t *mp, size_t alignment, size_t size)
NXT_MALLOC_LIKE;
/* nxt_mp_free() frees freeable memory. */
NXT_EXPORT void nxt_mp_free(nxt_mp_t *mp, void *p);
/*
* nxt_mp_retain() returns aligned freeable memory and increases memory
* pool retention counter.
*/
NXT_EXPORT void *nxt_mp_retain(nxt_mp_t *mp, size_t size)
NXT_MALLOC_LIKE;
/*
* nxt_mp_release() returns freeable memory and decreases memory pool
* retention counter. If the counter becomes zero the pool is destroyed.
*/
NXT_EXPORT void nxt_mp_release(nxt_mp_t *mp, void *p);
/* nxt_mp_nget() returns non-aligned non-freeable memory. */
NXT_EXPORT void *nxt_mp_nget(nxt_mp_t *mp, size_t size)
NXT_MALLOC_LIKE;
/*
* nxt_mp_get() returns aligned non-freeable memory.
* The alignment is sutiable to allocate structures.
*/
NXT_EXPORT void *nxt_mp_get(nxt_mp_t *mp, size_t size)
NXT_MALLOC_LIKE;
/*
* nxt_mp_zget() returns zeroed aligned non-freeable memory.
* The alignment is sutiable to allocate structures.
*/
NXT_EXPORT void *nxt_mp_zget(nxt_mp_t *mp, size_t size)
NXT_MALLOC_LIKE;
#endif /* _NXT_MP_H_INCLUDED_ */
