<< Previous | Next >>

pool_init

int pool_init( Pool_t * p, void * base, word nel, word elsize );

Description

Initialize a root memory pool. A pool is a linked list of fixed-size blocks taken from a contiguous area. You can use pools instead of malloc() when fixed-size blocks are all that is needed. You can have several pools, with different size blocks. Using memory pools is very efficient compared with more general functions like malloc(). (There is currently no malloc() implementation with Dynamic C.)

This function should only be called once, at program startup time, for each pool to be used.

Note: the product of nel and elsize must be less than 65535 (however, this will usually be limited further by the actual amount of root memory available).

After calling this function, your application must not change any of the fields in the Pool_t structure.

Parameters

p

Pool handle structure. This is allocated by the caller, but this function will initialize it. Normally, this would be allocated in static memory by declaring a global variable of type Pool_t.

base

Base address of the root data memory area to be managed in this pool. This must be nel*elsize bytes long. Typically, this would be a static (global) array.

nel

Number of elements in the memory area. 1..32767

elsize

Size of each element in the memory area. 2..32767

Return value

Currently always zero. If you define the macro POOL_DEBUG, then parameters are checked. If the parameters look bad, then an exception is raised. You can define POOL_VERBOSE to get printf() messages.

Library

POOL.LIB

See Also

pool_xinit, palloc, pcalloc, pfree, phwm, pavail