Memory block management functions

The memory block allocation routines provide a simple yet powerful set of functions for managing a set of memory blocks of fixed size. More...

Files
file	memb.c
	Memory block allocation routines.
file	memb.h
	Memory block allocation routines.
Defines
#define	MEMB(name, structure, num)
	Declare a memory block.
Functions
void	memb_init (struct memb *m)
	Initialize a memory block that was declared with MEMB().
void *	memb_alloc (struct memb *m)
	Allocate a memory block from a block of memory declared with MEMB().
char	memb_free (struct memb *m, void *ptr)
	Deallocate a memory block from a memory block previously declared with MEMB().

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Detailed Description

The memory block allocation routines provide a simple yet powerful set of functions for managing a set of memory blocks of fixed size.

A set of memory blocks is statically declared with the MEMB() macro. Memory blocks are allocated from the declared memory by the memb_alloc() function, and are deallocated with the memb_free() function.

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Define Documentation

#define MEMB	(		name,
			structure,
			num
	)

Value:

static char CC_CONCAT(name,_memb_count)[num]; \
        static structure CC_CONCAT(name,_memb_mem)[num]; \
        static struct memb name = {sizeof(structure), num, \
                                          CC_CONCAT(name,_memb_count), \
                                          (void *)CC_CONCAT(name,_memb_mem)}

Declare a memory block.

This macro is used to statically declare a block of memory that can be used by the block allocation functions. The macro statically declares a C array with a size that matches the specified number of blocks and their individual sizes.

Example:

MEMB(connections, struct connection, 16);

Parameters:

name	The name of the memory block (later used with memb_init(), memb_alloc() and memb_free()).
structure	The name of the struct that the memory block holds
num	The total number of memory chunks in the block.

Examples:

example-multihop.c, and example-runicast.c.

Definition at line 90 of file memb.h.

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Function Documentation

void * memb_alloc

(

struct memb *

m

)

Allocate a memory block from a block of memory declared with MEMB().

Parameters:

m	A memory block previously declared with MEMB().

Examples:

example-multihop.c, and example-runicast.c.

Definition at line 60 of file memb.c.

References NULL.

Referenced by packetqueue_enqueue_packetbuf().

char memb_free	(	struct memb *	m,
		void *	ptr
	)

Deallocate a memory block from a memory block previously declared with MEMB().

Parameters:

m	m A memory block previously declared with MEMB().
ptr	A pointer to the memory block that is to be deallocated.

Returns:

The new reference count for the memory block (should be 0 if successfully deallocated) or -1 if the pointer "ptr" did not point to a legal memory block.

Examples:

example-multihop.c.

Definition at line 80 of file memb.c.

Referenced by packetqueue_dequeue(), and packetqueue_enqueue_packetbuf().

void memb_init

(

struct memb *

m

)

Initialize a memory block that was declared with MEMB().

Parameters:

m	A memory block previously declared with MEMB().

Examples:

example-multihop.c, and example-runicast.c.

Definition at line 53 of file memb.c.

Referenced by packetqueue_init().