/*
 * $Id$
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file MEM_guardedalloc.h
 *  \ingroup MEM
 *
 *  \author Copyright (C) 2001 NaN Technologies B.V.
 *  \brief Read \ref MEMPage
 */

/** 
 * \page MEMPage Guarded memory(de)allocation
 *
 * \section aboutmem c-style guarded memory allocation
 *
 * \subsection memabout About the MEM module
 *
 * MEM provides guarded malloc/calloc calls. All memory is enclosed by
 * pads, to detect out-of-bound writes. All blocks are placed in a
 * linked list, so they remain reachable at all times. There is no
 * back-up in case the linked-list related data is lost.
 *
 * \subsection memissues Known issues with MEM
 *
 * There are currently no known issues with MEM. Note that there is a
 * second intern/ module with MEM_ prefix, for use in c++.
 * 
 * \subsection memdependencies Dependencies
 * - stdlib
 * - stdio
 * 
 * \subsection memdocs API Documentation
 * See \ref MEM_guardedalloc.h
 */

#ifndef MEM_MALLOCN_H
#define MEM_MALLOCN_H

#include <stdio.h> /* needed for FILE* */
#include "MEM_sys_types.h" /* needed for uintptr_t */

#ifndef WARN_UNUSED
#  ifdef __GNUC__
#    define WARN_UNUSED  __attribute__((warn_unused_result))
#  else
#    define WARN_UNUSED
#  endif
#endif

#ifdef __cplusplus
extern "C" {
#endif

	/** Returns the length of the allocated memory segment pointed at
	 * by vmemh. If the pointer was not previously allocated by this
	 * module, the result is undefined.*/
	size_t MEM_allocN_len(void *vmemh) WARN_UNUSED;

	/**
	 * Release memory previously allocatred by this module. 
	 */
	short MEM_freeN(void *vmemh);
	short WMEM_freeN(void *vmemh);
	
	short _MEM_freeN(void *vmemh, const char *file, int line);
	#define MEM_freeN(vmemh)	_MEM_freeN(vmemh, __FILE__, __LINE__)
	

	/**
	 * Return zero if memory is not in allocated list
	 */
	short MEM_testN(void *vmemh);

	/**
	 * Duplicates a block of memory, and returns a pointer to the
	 * newly allocated block.  */
	void *MEM_dupallocN(void *vmemh) WARN_UNUSED;

	/**
	  * Reallocates a block of memory, and returns pointer to the newly
	  * allocated block, the old one is freed. this is not as optimized
	  * as a system realloc but just makes a new allocation and copies
	  * over from existing memory. */
	void *MEM_reallocN(void *vmemh, size_t len) WARN_UNUSED;

	/**
	 * Allocate a block of memory of size len, with tag name str. The
	 * memory is cleared. The name must be static, because only a
	 * pointer to it is stored ! */
	void *MEM_callocN(size_t len, const char * str) WARN_UNUSED;
	
	/** Allocate a block of memory of size len, with tag name str. The
		* name must be a static, because only a pointer to it is stored !
		* */
	void *MEM_mallocN(size_t len, const char * str) WARN_UNUSED;
	
	/** Same as callocN, clears memory and uses mmap (disk cached) if supported.
		Can be free'd with MEM_freeN as usual.
		* */
	void *MEM_mapallocN(size_t len, const char * str) WARN_UNUSED;

	/** Print a list of the names and sizes of all allocated memory
	 * blocks. as a python dict for easy investigation */ 
	void MEM_printmemlist_pydict(void);

	/** Print a list of the names and sizes of all allocated memory
	 * blocks. */ 
	void MEM_printmemlist(void);

	/** calls the function on all allocated memory blocks. */
	void MEM_callbackmemlist(void (*func)(void*));

	/** Print statistics about memory usage */
	void MEM_printmemlist_stats(void);
	
	/** Set the callback function for error output. */
	void MEM_set_error_callback(void (*func)(const char *));

	/**
	 * Are the start/end block markers still correct ?
	 *
	 * @retval 0 for correct memory, 1 for corrupted memory. */
	int MEM_check_memory_integrity(void);

	/** Set thread locking functions for safe memory allocation from multiple
	    threads, pass NULL pointers to disable thread locking again. */
	void MEM_set_lock_callback(void (*lock)(void), void (*unlock)(void));
	
	/** Attempt to enforce OSX (or other OS's) to have malloc and stack nonzero */
	void MEM_set_memory_debug(void);

	/** Memory usage stats
	 * - MEM_get_memory_in_use is all memory
	 * - MEM_get_mapped_memory_in_use is a subset of all memory */
	uintptr_t MEM_get_memory_in_use(void);
	/** Get mapped memory usage. */
	uintptr_t MEM_get_mapped_memory_in_use(void);
	/** Get amount of memory blocks in use. */
	int MEM_get_memory_blocks_in_use(void);

	/** Reset the peak memory statistic to zero. */
	void MEM_reset_peak_memory(void);

	/** Get the peak memory usage in bytes, including mmap allocations. */
	uintptr_t MEM_get_peak_memory(void) WARN_UNUSED;

/* all memory chunks are put in linked lists */
typedef struct localLink
{
	struct localLink *next,*prev;
} localLink;

typedef struct localListBase
{
	void *first, *last;
} localListBase;

	/* note: keep this struct aligned (e.g., irix/gcc) - Hos */
typedef struct MemHead {
	int tag1;
	size_t len;
	struct MemHead *next,*prev;
	const char * name;
	const char * nextname;
	int tag2;
	int mmap;	/* if true, memory was mmapped */
#ifdef DEBUG_MEMCOUNTER
	int _count;
#endif
} MemHead;

typedef struct MemTail {
	int tag3, tag4;
} MemTail;

/*memory bias to hopefully account 
  for allocation overhead from
  the system allocator.*/
#define MEM_OVERHEADBIAS	32

#define MEM_OVERHEAD	(sizeof(MemHead) + sizeof(MemTail) + MEM_OVERHEADBIAS)

/*reset the peak memory statistic to zero*/
void MEM_reset_peak_memory(void);

/*get the peak memory usage in bytes, including mmap allocations*/
uintptr_t MEM_get_peak_memory(void);

#ifndef NDEBUG
const char *MEM_name_ptr(void *vmemh);
#endif
	
#ifdef __cplusplus
}
#endif

#endif