#include <unistd.h>
#include "dmm_config.h"
#ifdef HAVE_LOCKS
#include <pthread.h>
#endif /* HAVE_LOCKS */
#include "dmm_init.h"

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

    /* FIXME Replace sbrk with a library call */
    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.mem_allocated = 0;
        main_allocator->heaps[i].dmm_stats.mem_requested = 0;
        main_allocator->heaps[i].dmm_stats.live_objects = 0;
        main_allocator->heaps[i].dmm_stats.num_malloc = 0;
        main_allocator->heaps[i].dmm_stats.num_free = 0;

        // Knobs initialization
        main_allocator->heaps[i].dmm_knobs.max_coalesce_size = -1;
        // FIXME Create a constant for the initial value of the next
        // variables
        main_allocator->heaps[i].dmm_knobs.frag_threshold = 1.0;
        main_allocator->heaps[i].dmm_knobs.mem_threshold = 17000;

#ifdef HAVE_LOCKS
        pthread_mutex_init(&main_allocator->heaps[i].mutex, NULL);
#endif /* HAVE_LOCKS */
    }

    // 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;
}