memb: Memory block management functions

Files
file	memb.c
	Memory block allocation routines.
file	memb.h
	Memory block allocation routines.

Macros
#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().
int	memb_free (struct memb *m, void *ptr)
	Deallocate a memory block from a memory block previously declared with MEMB().
int	memb_inmemb (struct memb *m, void *ptr)
	Check if a given address is within a memory area previously declared with MEMB().
size_t	memb_numfree (struct memb *m)
	Count free memory blocks.

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.

Macro Definition Documentation

MEMB

#define MEMB	(		name,
			structure,
			num )

Value:

        static bool CC_CONCAT(name,_memb_used)[num]; \
        static structure CC_CONCAT(name,_memb_mem)[num]; \
        static struct memb name = {sizeof(structure), num, \
                                          CC_CONCAT(name,_memb_used), \
                                          (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.

Definition at line 91 of file memb.h.

Function Documentation

memb_alloc()

void * memb_alloc

(

struct memb *

m

)

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

Parameters

m	A set of memory blocks previously declared with MEMB().

Definition at line 59 of file memb.c.

Referenced by sixp_trans_alloc(), tsch_queue_add_packet(), tsch_schedule_add_link(), tsch_schedule_add_slotframe(), uip_ds6_nbr_add(), uip_mcast6_route_add(), uip_nameserver_update(), and uip_sr_update_node().

memb_free()

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

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

Parameters

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

Returns

error code, should be 0 if successfully deallocated or -1 if the pointer "ptr" did not point to a legal memory block.

Definition at line 78 of file memb.c.

Referenced by sixp_trans_free(), tsch_queue_add_packet(), tsch_queue_free_packet(), tsch_schedule_remove_link(), tsch_schedule_remove_slotframe(), uip_ds6_nbr_add(), uip_mcast6_route_rm(), uip_nameserver_update(), uip_sr_free_all(), and uip_sr_periodic().

memb_init()

void memb_init

(

struct memb *

m

)

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

Parameters

m	A set of memory blocks previously declared with MEMB().

Definition at line 52 of file memb.c.

Referenced by sixp_trans_init(), tsch_queue_init(), tsch_schedule_init(), uip_mcast6_route_init(), and uip_sr_init().

memb_inmemb()

int memb_inmemb	(	struct memb *	m,
		void *	ptr )

Check if a given address is within a memory area previously declared with MEMB().

Parameters

m	m A set of memory blocks previously declared with MEMB().
ptr	A pointer to the address to check

Returns

1 if the address is part of the memory block; otherwise 0

Definition at line 101 of file memb.c.

memb_numfree()

size_t memb_numfree

(

struct memb *

m

)

Count free memory blocks.

Parameters

m	m A set of memory blocks previously declared with MEMB().

Returns

the number of free (available) memory blocks

Definition at line 108 of file memb.c.

Referenced by tsch_queue_global_packet_count().