dmmlib/dmm_adaptor.c

#include "dmm_adaptor.h"

void update_frag_params(heap_t *heap) {
    switch(heap->dmm_knobs.frag_state) {
        default :
            heap->dmm_knobs.percentage = 0;
            heap->dmm_knobs.max_coalesce_size = -1;
            heap->dmm_knobs.min_split_size = 0;
            heap->dmm_knobs.empty_threshold = 1.5;
            break;
        case 1 :
            heap->dmm_knobs.percentage = 20;
            heap->dmm_knobs.max_coalesce_size = 400;
            heap->dmm_knobs.min_split_size = 1200;
            break;
        case 2 :
            heap->dmm_knobs.percentage = 40;
            heap->dmm_knobs.max_coalesce_size = 800;
            heap->dmm_knobs.min_split_size = 1000;
            break;
        case 3 :
            heap->dmm_knobs.percentage = 60;
            heap->dmm_knobs.max_coalesce_size = 1200;
            heap->dmm_knobs.min_split_size = 800;
            break;
        case 4 :
            heap->dmm_knobs.percentage = 80;
            heap->dmm_knobs.max_coalesce_size = 1600;
            heap->dmm_knobs.min_split_size = 600;
            break;
        case 5 :
            heap->dmm_knobs.percentage = 100;
            heap->dmm_knobs.max_coalesce_size = 2000;
            heap->dmm_knobs.min_split_size = 300;
            break;
    }
}

void update_foot_params(heap_t *heap) {
    switch(heap->dmm_knobs.foot_state) {
        default :
            heap->dmm_knobs.empty_threshold = 0.8;
            break;
        case 2 :
            heap->dmm_knobs.empty_threshold = 0.6;
            break;
        case 3 :
            heap->dmm_knobs.empty_threshold = 0.4;
            break;
        case 4 :
            heap->dmm_knobs.empty_threshold = 0.2;
            break;
        case 5 :
            heap->dmm_knobs.empty_threshold = 0.0;
            break;
    }
}

float get_current_fragmentation(heap_t *heap) {
    float fragmentation;

    fragmentation = (float) heap->dmm_stats.mem_allocated / 
        (float)	heap->dmm_stats.mem_requested - 1.0;

    if(fragmentation <= MIN_FRAG_THRESHOLD &&
            heap->dmm_stats.mem_reserved < heap->dmm_knobs.mem_threshold) {
        heap->dmm_knobs.frag_state = 0;
        heap->dmm_knobs.foot_state = 0;
        update_frag_params(heap);
    }

    return fragmentation;
}

void check_footprint(heap_t *heap) {
    if(heap->dmm_stats.mem_allocated > heap->dmm_knobs.mem_threshold) {
        if(heap->dmm_knobs.frag_state > heap->dmm_knobs.foot_state) {
            heap->dmm_knobs.foot_state = heap->dmm_knobs.frag_state;
        } else {
            heap->dmm_knobs.foot_state++;
        }
        update_foot_params(heap);
    }
}

void malloc_state_refresh(heap_t *heap) {
    float fragmentation;

    fragmentation = get_current_fragmentation(heap); 

    /* Check fragmentation */
    if(fragmentation >= heap->dmm_knobs.frag_threshold &&
            heap->dmm_stats.mem_requested != 0) {
        if(heap->dmm_knobs.foot_state > heap->dmm_knobs.frag_state) {
            heap->dmm_knobs.frag_state = heap->dmm_knobs.foot_state;
        } else {
            heap->dmm_knobs.frag_state++;
        }
        update_frag_params(heap);
    }

    check_footprint(heap);
}

void free_state_refresh(heap_t *heap) {
    float fragmentation;

    fragmentation = get_current_fragmentation(heap);

    check_footprint(heap);
}