MEMPOOL
Description
Manages an already allocated memory region at a specified address by assigning blocks of a requested size. Once assigned, blocks are static and cannot be released or freed. This approach has the following advantages:
The managed memory region is divided according to a fixed sequence of block requests. The resulting memory map is deterministic, and the user documentation can precisely describe its arrangement.
No dynamic memory allocation implies no memory fragmentation and no need to handle the complexity of sudden out of memory conditions.
There might be several memory pools residing on different memory types (a given SRAM bank, external SDRAM, etc.), each one serving a different purpose.
The managed memory region address, each block assigned from it and their sizes align to a 64-bit boundary.
Design and development status
Feature-complete.
Changelog
Version |
Date* |
Author |
Comment |
|---|---|---|---|
1.0.0 |
2022.9.7 |
sgermino |
Initial release. |
* Date format is Year.Month.Day.
API reference
-
MEMPOOL_BLOCKSIZE_REMAINS
Request a block with the remaining mempool capacity.
-
struct MEMPOOL
The user should treat this as an opaque structure. No member should be directly accessed or modified.
-
void MEMPOOL_Init(struct MEMPOOL *const M, const uintptr_t BaseAddr, const uint32_t Size)
Initializes a
MEMPOOLinstance.- Parameters
BaseAddr – Memory region start address. The address must be aligned to a 64-bit boundary; this condition is asserted.
Size – Memory region size, in octets. Must be a multiple of eight; this condition is asserted.
-
void *MEMPOOL_Block(struct MEMPOOL *const M, const uint32_t ReqSize, const char *const Description)
Reserves and returns a memory block. The user must confirm there is enough space for a block allocation of the requested size; this condition is asserted. See
MEMPOOL_Available().- Parameters
ReqSize – Requested size or
MEMPOOL_BLOCKSIZE_REMAINSto ask for all space left. The returned memory block size is round up to the next multiple of eight.Description – Unique block name, purpose, or
NULL. The block will keep a copy of this pointer; it won’t duplicate the original string contents. The user must guarantee that the string pointer passed will not change its memory allocation to avoid a dangling pointer.
- Returns
Pointer to the new memory block address. The address is 64-bit aligned.
-
uint32_t MEMPOOL_BlockSize(void *const Block)
Returns a memory block size.
- Parameters
Block – A valid memory block pointer as returned by
MEMPOOL_Block(); this condition is asserted.
- Returns
Memory block size, in octets.