/*
* Copyright (c) 2007 Intel Corporation. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <stdlib.h>
#include <assert.h>
#include "object_heap.h"
#define ASSERT assert
#define LAST_FREE -1
#define ALLOCATED -2
/*
* Expands the heap
* Return 0 on success, -1 on error
*/
static int
object_heap_expand(object_heap_p heap)
{
int i;
void *new_heap_index;
int next_free;
int new_heap_size = heap->heap_size + heap->heap_increment;
int bucket_index = new_heap_size / heap->heap_increment - 1;
if (bucket_index >= heap->num_buckets) {
int new_num_buckets = heap->num_buckets + 8;
void **new_bucket;
new_bucket
= realloc(heap
->bucket
, new_num_buckets
* sizeof(void *)); if (NULL == new_bucket) {
return -1;
}
heap->num_buckets = new_num_buckets;
heap->bucket = new_bucket;
}
new_heap_index
= (void *) malloc(heap
->heap_increment
* heap
->object_size
); if (NULL == new_heap_index) {
return -1; /* Out of memory */
}
heap->bucket[bucket_index] = new_heap_index;
next_free = heap->next_free;
for (i = new_heap_size; i-- > heap->heap_size;) {
object_base_p obj = (object_base_p)(new_heap_index + (i - heap->heap_size) * heap->object_size);
obj->id = i + heap->id_offset;
obj->next_free = next_free;
next_free = i;
}
heap->next_free = next_free;
heap->heap_size = new_heap_size;
return 0; /* Success */
}
/*
* Return 0 on success, -1 on error
*/
int
object_heap_init(object_heap_p heap, int object_size, int id_offset)
{
pthread_mutex_init(&heap->mutex, NULL);
heap->object_size = object_size;
heap->id_offset = id_offset & OBJECT_HEAP_OFFSET_MASK;
heap->heap_size = 0;
heap->heap_increment = 16;
heap->next_free = LAST_FREE;
heap->num_buckets = 0;
heap->bucket = NULL;
return object_heap_expand(heap);
}
/*
* Allocates an object
* Returns the object ID on success, returns -1 on error
*/
static int
object_heap_allocate_unlocked(object_heap_p heap)
{
object_base_p obj;
int bucket_index, obj_index;
if (LAST_FREE == heap->next_free) {
if (-1 == object_heap_expand(heap)) {
return -1; /* Out of memory */
}
}
ASSERT(heap->next_free >= 0);
bucket_index = heap->next_free / heap->heap_increment;
obj_index = heap->next_free % heap->heap_increment;
obj = (object_base_p)(heap->bucket[bucket_index] + obj_index * heap->object_size);
heap->next_free = obj->next_free;
obj->next_free = ALLOCATED;
return obj->id;
}
int
object_heap_allocate(object_heap_p heap)
{
int ret;
pthread_mutex_lock(&heap->mutex);
ret = object_heap_allocate_unlocked(heap);
pthread_mutex_unlock(&heap->mutex);
return ret;
}
/*
* Lookup an object by object ID
* Returns a pointer to the object on success, returns NULL on error
*/
static object_base_p
object_heap_lookup_unlocked(object_heap_p heap, int id)
{
object_base_p obj;
int bucket_index, obj_index;
if ((id < heap->id_offset) || (id > (heap->heap_size + heap->id_offset))) {
return NULL;
}
id &= OBJECT_HEAP_ID_MASK;
bucket_index = id / heap->heap_increment;
obj_index = id % heap->heap_increment;
obj = (object_base_p)(heap->bucket[bucket_index] + obj_index * heap->object_size);
/* Check if the object has in fact been allocated */
if (obj->next_free != ALLOCATED) {
return NULL;
}
return obj;
}
object_base_p
object_heap_lookup(object_heap_p heap, int id)
{
object_base_p obj;
pthread_mutex_lock(&heap->mutex);
obj = object_heap_lookup_unlocked(heap, id);
pthread_mutex_unlock(&heap->mutex);
return obj;
}
/*
* Iterate over all objects in the heap.
* Returns a pointer to the first object on the heap, returns NULL if heap is empty.
*/
object_base_p
object_heap_first(object_heap_p heap, object_heap_iterator *iter)
{
*iter = -1;
return object_heap_next(heap, iter);
}
/*
* Iterate over all objects in the heap.
* Returns a pointer to the next object on the heap, returns NULL if heap is empty.
*/
static object_base_p
object_heap_next_unlocked(object_heap_p heap, object_heap_iterator *iter)
{
object_base_p obj;
int bucket_index, obj_index;
int i = *iter + 1;
while (i < heap->heap_size) {
bucket_index = i / heap->heap_increment;
obj_index = i % heap->heap_increment;
obj = (object_base_p)(heap->bucket[bucket_index] + obj_index * heap->object_size);
if (obj->next_free == ALLOCATED) {
*iter = i;
return obj;
}
i++;
}
*iter = i;
return NULL;
}
object_base_p
object_heap_next(object_heap_p heap, object_heap_iterator *iter)
{
object_base_p obj;
pthread_mutex_lock(&heap->mutex);
obj = object_heap_next_unlocked(heap, iter);
pthread_mutex_unlock(&heap->mutex);
return obj;
}
/*
* Frees an object
*/
static void
object_heap_free_unlocked(object_heap_p heap, object_base_p obj)
{
/* Check if the object has in fact been allocated */
ASSERT(obj->next_free == ALLOCATED);
obj->next_free = heap->next_free;
heap->next_free = obj->id & OBJECT_HEAP_ID_MASK;
}
void
object_heap_free(object_heap_p heap, object_base_p obj)
{
if (!obj)
return;
pthread_mutex_lock(&heap->mutex);
object_heap_free_unlocked(heap, obj);
pthread_mutex_unlock(&heap->mutex);
}
/*
* Destroys a heap, the heap must be empty.
*/
void
object_heap_destroy(object_heap_p heap)
{
object_base_p obj;
int bucket_index, obj_index, i;
/* Check if heap is empty */
for (i = 0; i < heap->heap_size; i++) {
/* Check if object is not still allocated */
bucket_index = i / heap->heap_increment;
obj_index = i % heap->heap_increment;
obj = (object_base_p)(heap->bucket[bucket_index] + obj_index * heap->object_size);
ASSERT(obj->next_free != ALLOCATED);
}
for (i = 0; i < heap->heap_size / heap->heap_increment; i++) {
}
pthread_mutex_destroy(&heap->mutex);
heap->bucket = NULL;
heap->heap_size = 0;
heap->next_free = LAST_FREE;
}