dmmlib/src/custom_malloc.c

/*
 *   Copyright 2011 Institute of Communication and Computer Systems (ICCS) 
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */

#include <dmmlib/dmmlib.h>
#include "dmm_config.h"
#ifdef HAVE_LOCKS
#include "posix_lock.h"
#endif /* HAVE_LOCKS */
#if defined (SPLITTING_FIXED) || defined (SPLITTING_VARIABLE)
#include "split.h"
#endif /* SPLITTING_FIXED || SPLITTING_VARIABLE */
#include <dmmlib/initialize_allocator.h>
#include "other.h"
#include "linked_lists/linked_lists.h"
#include "linked_lists/search_algorithms.h"
#include "sys_alloc.h"
#include "block_header.h"
#ifdef WITH_ADAPTIVITY
#include "dmm_adaptor.h"
#endif /* WITH_ADAPTIVITY */

void * custom_ahmalloc(allocator_t* allocator, heap_t* heap, size_t size) {
    void *ptr;
#if defined (SPLITTING_FIXED) || defined (SPLITTING_VARIABLE)
    size_t new_size;
    size_t min_split_size;
#endif /* (SPLITTING_FIXED) || (SPLITTING_VARIABLE) */

#ifndef WITH_MEMORY_SPACE_AWARENESS
    int heap_id;

    /* Go to the system allocator if none was given */
    if(allocator == NULL) {
        allocator = &systemallocator;
        if(allocator->initialized != true) {
            initialize_allocator(allocator);
        }
    }

    if(heap == NULL) {
        heap_id = map_thread_heap();
        heap = &allocator->heaps[heap_id];
    }

#endif /* WITH_MEMORY_SPACE_AWARENESS */

    ptr = NULL;

#ifdef HAVE_LOCKS
    posix_lock(heap);
#endif /* HAVE_LOCKS */

#ifdef WITH_FIXED_LISTS
    ptr = search_on_fixed(heap, req_padding(size));

    if(ptr == NULL) {
#endif /* WITH_FIXED_LISTS */
       ptr = best_fit_on_freelist(heap, size);
#ifdef WITH_FIXED_LISTS
    }
#endif /* WITH_FIXED_LISTS */

    if(ptr != NULL) {

#ifdef FUTURE_FEATURES
        set_requested_size(ptr, size);
#endif /* FUTURE_FEATURES */

        /* Try to split */
#if defined (SPLITTING_FIXED) || defined (SPLITTING_VARIABLE)
        /* Check what would be the size of the new block if we split the current
         * one.
         * Note: new_size is a size_t, so compare first in order to prevent an
         * underflow.
         */
        if(get_size(ptr) > size + HEADER_SIZE) {
            new_size = get_size(ptr) - size - HEADER_SIZE;
        } else {
            new_size = 0;
        }

#ifdef SPLITTING_FIXED
        min_split_size = MIN_SPLITTING_SIZE;
#endif /* SPLITTING_FIXED */
#ifdef SPLITTING_VARIABLE
        min_split_size = heap->dmm_knobs.min_split_size;
#endif /* SPLITTING_VARIABLE */

        if(new_size >= min_split_size) {
            split(allocator, heap, ptr, size);
        }
#endif /* (SPLITTING_FIXED) || (SPLITTING_VARIABLE) */

        mark_used(allocator, ptr);

#ifdef FUTURE_FEATURES
        /* Update the used blocks list */
        push_block(&ptr, &heap->used_blocks_head);
#endif /* FUTURE_FEATURES */

#ifdef WITH_STATS
        /* Update statistics */
        heap->dmm_stats.mem_allocated += req_padding(size);
        heap->dmm_stats.mem_requested += size;
        heap->dmm_stats.live_objects += 1;
        heap->dmm_stats.num_malloc += 1;
#endif /* WITH_STATS */

        /* FIXME To be refactored - END */

    } else {
        ptr = sys_alloc(allocator, heap, size);
    }

#ifdef WITH_ADAPTIVITY
    /* Refresh the state of the heap allocator if a certain number of
     * malloc's has been served already
     */
    /* TODO Define 50 as a constant */
    if(heap->dmm_stats.num_malloc % 50) {
        malloc_state_refresh(heap);
    }
#endif /* WITH_ADAPTIVITY */

#ifdef HAVE_LOCKS
    posix_unlock(heap);
#endif /* HAVE_LOCKS */
    return ptr;
}

/* Currently all the memory space aware allocators are pre-initialized, so
 * we do not expect any custom_ahmalloc call without knowing which allocator
 * and heap are to be used.
 */
#ifndef WITH_MEMORY_SPACE_AWARENESS
void * custom_malloc(size_t size) {
    return custom_ahmalloc(NULL, NULL, size);
}
#endif /* WITH_MEMORY_SPACE_AWARENESS */