ardupilot/libraries/AP_MultiHeap/MultiHeap_malloc.cpp

120 lines
3.0 KiB
C++

#include "AP_MultiHeap.h"
#include <AP_HAL/AP_HAL_Boards.h>
#if ENABLE_HEAP && CONFIG_HAL_BOARD != HAL_BOARD_CHIBIOS
/*
on systems other than chibios we map the allocation to the system
malloc/free functions
*/
#include <AP_InternalError/AP_InternalError.h>
#include <stdlib.h>
/*
low level allocator interface using system malloc
*/
/*
default functions for heap management for lua scripting for systems
that don't have the ability to create separable heaps
*/
struct heap_allocation_header {
struct heap *hp;
uint32_t allocation_size; // size of allocated block, not including this header
};
#define HEAP_MAGIC 0x5681ef9f
struct heap {
uint32_t magic;
uint32_t max_heap_size;
uint32_t current_heap_usage;
};
void *MultiHeap::heap_create(uint32_t size)
{
struct heap *new_heap = (struct heap*)malloc(sizeof(struct heap));
if (new_heap != nullptr) {
new_heap->max_heap_size = size;
}
new_heap->magic = HEAP_MAGIC;
return (void *)new_heap;
}
void MultiHeap::heap_destroy(void *heap_ptr)
{
struct heap *heapp = (struct heap*)heap_ptr;
if (heapp->magic != HEAP_MAGIC) {
INTERNAL_ERROR(AP_InternalError::error_t::flow_of_control);
return;
}
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
if (heapp->current_heap_usage != 0) {
// lua should guarantee that there is no memory still
// allocated when we destroy the heap. Throw an error in SITL
// if this proves not to be true
INTERNAL_ERROR(AP_InternalError::error_t::flow_of_control);
}
#endif
// free the heap structure
free(heapp);
}
/*
allocate memory on a specific heap
*/
void *MultiHeap::heap_allocate(void *heap_ptr, uint32_t size)
{
if (heap_ptr == nullptr || size == 0) {
return nullptr;
}
struct heap *heapp = (struct heap*)heap_ptr;
if (heapp->magic != HEAP_MAGIC) {
INTERNAL_ERROR(AP_InternalError::error_t::flow_of_control);
return nullptr;
}
if (heapp->current_heap_usage + size > heapp->max_heap_size) {
// fail the allocation as we don't have the memory. Note that
// we don't simulate the fragmentation that we would get with
// HAL_ChibiOS
return nullptr;
}
auto *header = (heap_allocation_header *)malloc(size + sizeof(heap_allocation_header));
if (header == nullptr) {
// can't allocate the new memory
return nullptr;
}
header->hp = heapp;
header->allocation_size = size;
heapp->current_heap_usage += size;
return header + 1;
}
/*
free memory from a previous heap_allocate call
*/
void MultiHeap::heap_free(void *ptr)
{
// extract header
auto *header = ((struct heap_allocation_header *)ptr)-1;
auto *heapp = header->hp;
if (heapp->magic != HEAP_MAGIC) {
INTERNAL_ERROR(AP_InternalError::error_t::flow_of_control);
return;
}
const uint32_t size = header->allocation_size;
heapp->current_heap_usage -= size;
// free the memory
free(header);
}
#endif // ENABLE_HEAP && CONFIG_HAL_BOARD != HAL_BOARD_CHIBIOS