Datasheet

The C and C++ Libraries

4.8.6 __Heap_ProvideMemory()

Called to increase the size of the heap.

Syntax

void __Heap_ProvideMemory(struct __Heap_Descriptor* h, void* base, size_t size)

Implementation

This is called when the system provides a chunk of memory for use by the heap. The

parameters are:

• your heap descriptor

• a pointer to a new 8-byte aligned block of memory

• the size of the block.

__Heap_ProvideMemory()

can assume that the input block is 8-byte aligned. A typical

__Heap_ProvideMemory()

implementation might set up the new block of memory as a

free-list entry and add it to the free chain.

4.8.7 __Heap_Alloc()

Allocates memory from the heap to the application.

Syntax

void __Heap_Alloc(struct __Heap_Descriptor* h, size_t size)

Implementation

This is called from

malloc()

, and mustreturn a pointer to

size

bytes of memory allocated

from the heap, or

NULL

if nothing can be allocated. You must ensure that the size of the

block can be determined when it is time to free it. The returned block size is typically

stored in the word immediately before its start address. The default implementation of

this function allocates an 8-byte aligned block of memory. If you reimplement this

function it is recommended that you return 8-byte aligned blocks of memory.