dmmlib/heap.h

/**
 * \file 	heap.h
 * \author 	Ioannis Koutras (joko@microlab.ntua.gr)
 * \date 	September, 2011
 * \brief 	Basic structures needed for the dmmlib allocator.
 */

#ifndef HEAP_H
#define HEAP_H

#include <stdint.h>
#include <stdbool.h>

#ifdef HAVE_LOCKS
#include <pthread.h>
#endif /* HAVE_LOCKS */

#include "block_header.h"

/**
 * \brief The number of the heaps.
 */
#define NUM_HEAPS 4

/**
 * \brief A structure to represent a maptable node.
 */
typedef struct maptable_node_s {
	unsigned int size; /**< \brief The size of the blocks of the fixed
			     list. */
	void *fixed_list_head; /**< \brief Pointer to the head node of the
				 fixed list. */
	struct maptable_node_s *next; /**< \brief Pointer to the next node of
					the maptable. */
} maptable_node_t;

/**
 * \brief Statistics data structure.
 */
typedef struct dmmstats_s {
	uint32_t max_mem_allocated; /**< \brief Maximum total memory
				      allocated. */
	uint32_t max_mem_requested; /**< \brief Maximum total memory
				      requested. */
	uint32_t mem_allocated; /**< \brief Total memory currently
				  allocated. */
	uint32_t mem_requested; /**< \brief Total memory currently
				  requested. */
	uint32_t mem_reserved; /**< \brief Total memory currently
				 reserved. */
	uint32_t live_objects; /**< \brief Number of live objects. */
	uint32_t read_mem_accesses; /**< \brief Number of read accesses. */
	uint32_t write_mem_accesses; /**< \brief Number of write accesses. */
	uint32_t num_malloc; /**< \brief Number of malloc()'s served. */
	uint32_t num_free; /**< \brief Number of free()'s served. */
} dmmstats_t;

/**
 * \brief A structure to represent tunable parameters of a heap
 */
typedef struct dmmknobs_s {
	/** \brief Maximum coalesce size; -1 If coalescing is not supported */
	int32_t max_coalesce_size;
	float frag_threshold; /**< \brief Fragmentation threshold to enable
				coalescing or not. */ 
	uint32_t mem_threshold; /**< \brief Memory size threshold. */
	uint32_t min_split_size; /**< \brief Minimum split size. */
	float empty_threshold; /**< FIXME Need to find explanation \brief Empty
				 Threshold */
	/*
	uint32_t percentage; // FIXME to be investigated if needed
	char frag_state; //FIXME It was in the old code to refresh the frag check
	*/
} dmmknobs_t;

/**
 * \brief A structure to store heap information.
 */
typedef struct heap_s {
	maptable_node_t *maptable_head; /**< \brief The head of the maptable list. */
	void *free_list_head; /**< \brief The head of the free list. */
	void *used_blocks_head; /**< \brief The head of the used blocks list. */
	void *rov_ptr; /**< \brief Roving pointer. */
	uint64_t num_objects; /**< \brief Number of objects in the heap. */
	dmmstats_t dmm_stats; /**< \brief Statistics of the heap. */
	dmmknobs_t dmm_knobs; /**< \brief Tunable parameters of the heap. */
#ifdef HAVE_LOCKS
	pthread_mutex_t mutex;/**< \brief Mutex when POSIX Threads are used. */
#endif /* HAVE_LOCKS */
} heap_t;

/**
 * \brief The allocator structure of dmmlib.
 */
typedef struct allocator_s {
	heap_t heaps[NUM_HEAPS]; /**< \brief The heaps that the allocator manages. */
	bool initialized; /**< \brief Initialization flag of the allocator. */
} allocator_t;

#endif /* HEAP_H */