dmmlib/dmm_init.c

#define _BSD_SOURCE
#include <unistd.h>
#include <pthread.h>
#include "dmm_init.h"

allocator_t * dmm_init(void) {
	int i;
	allocator_t *main_allocator;
	heap_t *current_heap;
	maptable_node_t *maptablenode;

	main_allocator = (allocator_t *) sbrk((int) sizeof(allocator_t));

	for(i = 0; i < NUM_HEAPS; i++) {
		main_allocator->heaps[i].maptable_head = NULL;
		main_allocator->heaps[i].free_list_head = NULL;
		main_allocator->heaps[i].used_blocks_head = NULL;
		main_allocator->heaps[i].rov_ptr = NULL;
		main_allocator->heaps[i].num_objects = 0;
		main_allocator->heaps[i].dmm_stats.num_malloc = 0;
		main_allocator->heaps[i].dmm_stats.num_free = 0;
		pthread_mutex_init(&main_allocator->heaps[i].mutex, NULL);
	}

	// Custom number of fixed lists and their initialization
	// 2 first ones with 32, 64, 128 and 256 (4 fixed lists per heap)
	// 2 last ones with 64 and 256 (2 fixed lists per heap)
	// 2 * 4 + 2 * 2 = 12 maptable nodes
	current_heap = &main_allocator->heaps[0];
	maptablenode = (maptable_node_t *) sbrk((int)(12*(sizeof(maptable_node_t))));

	maptablenode->size = 32;
	maptablenode->fixed_list_head = NULL;
	maptablenode->next = maptablenode+1;
	current_heap->maptable_head = maptablenode;
	(maptablenode+1)->size = 64;
	(maptablenode+1)->fixed_list_head = NULL;
	(maptablenode+1)->next = maptablenode+2;
	(maptablenode+2)->size = 128;
	(maptablenode+2)->fixed_list_head = NULL;
	(maptablenode+2)->next = maptablenode+3;
	(maptablenode+3)->size = 256;
	(maptablenode+3)->fixed_list_head = NULL;
	(maptablenode+3)->next = NULL;
	current_heap = &main_allocator->heaps[1];
	maptablenode += 4;
	maptablenode->size = 32;
	maptablenode->fixed_list_head = NULL;
	maptablenode->next = maptablenode+1;
	current_heap->maptable_head = maptablenode;
	(maptablenode+1)->size = 64;
	(maptablenode+1)->fixed_list_head = NULL;
	(maptablenode+1)->next = maptablenode+2;
	(maptablenode+2)->size = 128;
	(maptablenode+2)->fixed_list_head = NULL;
	(maptablenode+2)->next = maptablenode+3;
	(maptablenode+3)->size = 256;
	(maptablenode+3)->fixed_list_head = NULL;
	(maptablenode+3)->next = NULL;
	current_heap = &main_allocator->heaps[2];
	maptablenode += 4;
	maptablenode->size = 64;
	maptablenode->fixed_list_head = NULL;
	maptablenode->next = maptablenode+1;
	current_heap->maptable_head = maptablenode;
	(maptablenode+1)->size = 256;
	(maptablenode+1)->fixed_list_head = NULL;
	(maptablenode+1)->next = NULL;
	current_heap = &main_allocator->heaps[3];
	maptablenode += 2;
	maptablenode->size = 64;
	maptablenode->fixed_list_head = NULL;
	maptablenode->next = maptablenode+1;
	current_heap->maptable_head = maptablenode;
	(maptablenode+1)->size = 256;
	(maptablenode+1)->fixed_list_head = NULL;
	(maptablenode+1)->next = NULL;

	return main_allocator;
}