objpool.h File Reference

#include <stdint.h>
#include <event_machine/platform/env/environment.h>
#include "list.h"

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Data Structures
struct	objpool_elem_t
union	objsubpool_t
struct	objpool_t

Macros
#define	OBJSUBPOOLS_MAX   8

Functions
	COMPILE_TIME_ASSERT (2 *sizeof(objsubpool_t)==ENV_CACHE_LINE_SIZE, OBJSUBPOOL_T_SIZE_ERROR)
int	objpool_init (objpool_t *const objpool, uint32_t nbr_subpools)
uint32_t	objpool_subpools (const objpool_t *const objpool)
void	objpool_add (objpool_t *const objpool, uint32_t subpool_idx, objpool_elem_t *const elem)
objpool_elem_t *	objpool_rem (objpool_t *const objpool, uint32_t subpool_idx)
int	objpool_rem_elem (objpool_t *const objpool, objpool_elem_t *const elem)

Detailed Description

Simple object pool for managing collections of objects.

Objects stored in the pool must embed an objpool_elem_t member that is used internally to link the object into the pool. The pool is divided into independently locked subpools to reduce contention in multithreaded use.

Definition in file objpool.h.

Macro Definition Documentation

OBJSUBPOOLS_MAX

#define OBJSUBPOOLS_MAX   8

Maximum number of subpools in an object pool.

This compile-time limit is set to 8 as a balance between reducing lock contention (more subpools) and keeping the objpool_t structure small enough to preserve cache locality. Increasing this value is possible if a particular workload benefits from more independently locked subpools, but doing so will grow the size of objpool_t proportionally.

Definition at line 62 of file objpool.h.

Function Documentation

objpool_add()

void objpool_add	(	objpool_t *const	objpool,
		uint32_t	subpool_idx,
		objpool_elem_t *const	elem
	)

Add an object to the object pool.

Parameters

objpool	Object pool.
subpool_idx	Index of the subpool to add the element to (modulo nbr_subpools).
elem	Object pool element embedded in the object to add.

Definition at line 63 of file objpool.c.

objpool_init()

int objpool_init	(	objpool_t *const	objpool,
		uint32_t	nbr_subpools
	)

Initialize an object pool.

Parameters

objpool	Object pool to initialize.
nbr_subpools	Number of subpools, clamped to OBJSUBPOOLS_MAX.

Returns

0 on success.

Return values

<0	on failure (invalid parameters).

Definition at line 38 of file objpool.c.

objpool_rem()

objpool_elem_t * objpool_rem	(	objpool_t *const	objpool,
		uint32_t	subpool_idx
	)

Remove and return an object from the object pool.

Tries the given subpool first, then searches the remaining subpools round-robin until a free object is found.

Parameters

objpool	Object pool.
subpool_idx	Preferred subpool index to remove from first.

Returns

Pointer to the removed element, or NULL if the pool is empty.

Definition at line 78 of file objpool.c.

objpool_rem_elem()

int objpool_rem_elem	(	objpool_t *const	objpool,
		objpool_elem_t *const	elem
	)

Remove a specific object from the object pool.

Parameters

objpool	Object pool.
elem	Object pool element to remove.

Returns

0 on success, -1 if the element was not in the pool.

Definition at line 104 of file objpool.c.

objpool_subpools()

uint32_t objpool_subpools

(

const objpool_t *const

objpool

)

Return the number of subpools in use by the object pool.

Parameters

objpool

Object pool.

Returns

Number of subpools.

Definition at line 58 of file objpool.c.