/**
 * $Id$
 * ***** BEGIN GPL/BL DUAL 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. The Blender
 * Foundation also sells licenses for use in proprietary software under
 * the Blender License.  See http://www.blender.org/BL/ for information
 * about this.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, 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/BL DUAL LICENSE BLOCK *****
 */

/**

 * $Id$
 * Copyright (C) 2001 NaN Technologies B.V.
 * Guarded memory allocation, and boundary-write detection.
 */

#include <stdlib.h>
#include <string.h>	/* memcpy */
#include <stdarg.h>

/* mmap exception */
#if defined(AMIGA) || defined(__BeOS) || defined(WIN32)
#else
#include <sys/types.h>
#include <sys/mman.h>
#endif

#include "MEM_guardedalloc.h"

/* --------------------------------------------------------------------- */
/* Data definition                                                       */
/* --------------------------------------------------------------------- */
/* 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;
	int len;
	struct MemHead *next,*prev;
	const char * name;
	const char * nextname;
	int tag2;
	int mmap;	/* if true, memory was mmapped */
} MemHead;

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


/* --------------------------------------------------------------------- */
/* local functions                                                       */
/* --------------------------------------------------------------------- */

static void addtail(volatile localListBase *listbase, void *vlink);
static void remlink(volatile localListBase *listbase, void *vlink);
static void rem_memblock(MemHead *memh);
static void MemorY_ErroR(const char *block, const char *error);
static const char *check_memlist(MemHead *memh);

/* --------------------------------------------------------------------- */
/* locally used defines                                                  */
/* --------------------------------------------------------------------- */

#if defined( __sgi) || defined (__sun) || defined (__sun__) || defined (__sparc) || defined (__sparc__) || defined (__PPC__) || (defined (__APPLE__) && !defined(__LITTLE_ENDIAN__))
#define MAKE_ID(a,b,c,d) ( (int)(a)<<24 | (int)(b)<<16 | (c)<<8 | (d) )
#else
#define MAKE_ID(a,b,c,d) ( (int)(d)<<24 | (int)(c)<<16 | (b)<<8 | (a) )
#endif

#define MEMTAG1 MAKE_ID('M', 'E', 'M', 'O')
#define MEMTAG2 MAKE_ID('R', 'Y', 'B', 'L')
#define MEMTAG3 MAKE_ID('O', 'C', 'K', '!')
#define MEMFREE MAKE_ID('F', 'R', 'E', 'E')

#define MEMNEXT(x) ((MemHead *)(((char *) x) - ((char *) & (((MemHead *)0)->next))))
	
/* --------------------------------------------------------------------- */
/* vars                                                                  */
/* --------------------------------------------------------------------- */
	

volatile int totblock= 0;
volatile unsigned long mem_in_use= 0, mmap_in_use= 0;

volatile static struct localListBase _membase;
volatile static struct localListBase *membase = &_membase;
static void (*error_callback)(char *) = NULL;

#ifdef malloc
#undef malloc
#endif

#ifdef calloc
#undef calloc
#endif

#ifdef free
#undef free
#endif


/* --------------------------------------------------------------------- */
/* implementation                                                        */
/* --------------------------------------------------------------------- */

static void print_error(const char *str, ...)
{
	char buf[1024];
	va_list ap;

	va_start(ap, str);
	vsprintf(buf, str, ap);
	va_end(ap);

	if (error_callback) error_callback(buf);
}

int MEM_check_memory_integrity()
{
	const char* err_val = NULL;
	MemHead* listend;
	/* check_memlist starts from the front, and runs until it finds
	 * the requested chunk. For this test, that's the last one. */
	listend = membase->last;
	
	err_val = check_memlist(listend);

	if (err_val == 0) return 0;
	return 1;
}


void MEM_set_error_callback(void (*func)(char *))
{
	error_callback = func;
}


int MEM_allocN_len(void *vmemh)
{
	if (vmemh) {
		MemHead *memh= vmemh;
	
		memh--;
		return memh->len;
	} else
		return 0;
}

void *MEM_dupallocN(void *vmemh)
{
	void *newp= NULL;
	
	if (vmemh) {
		MemHead *memh= vmemh;
		memh--;
		
		if(memh->mmap)
			newp= MEM_mapallocN(memh->len, "dupli_alloc");
		else
			newp= MEM_mallocN(memh->len, "dupli_mapalloc");
		memcpy(newp, vmemh, memh->len);
	}

	return newp;
}

static void make_memhead_header(MemHead *memh, unsigned int len, const char *str)
{
	MemTail *memt;
	
	memh->tag1 = MEMTAG1;
	memh->name = str;
	memh->nextname = 0;
	memh->len = len;
	memh->mmap = 0;
	memh->tag2 = MEMTAG2;
	
	memt = (MemTail *)(((char *) memh) + sizeof(MemHead) + len);
	memt->tag3 = MEMTAG3;
	
	addtail(membase,&memh->next);
	if (memh->next) memh->nextname = MEMNEXT(memh->next)->name;
	
	totblock++;
	mem_in_use += len;
}

void *MEM_mallocN(unsigned int len, const char *str)
{
	MemHead *memh;

	len = (len + 3 ) & ~3; 	/* allocate in units of 4 */
	
	memh= (MemHead *)malloc(len+sizeof(MemHead)+sizeof(MemTail));

	if(memh) {
		make_memhead_header(memh, len, str);
		return (++memh);
	}
	print_error("Malloc returns nill: len=%d in %s, total %u\n",len, str, mem_in_use);
	return NULL;
}

void *MEM_callocN(unsigned int len, const char *str)
{
	MemHead *memh;

	len = (len + 3 ) & ~3; 	/* allocate in units of 4 */

	memh= (MemHead *)calloc(len+sizeof(MemHead)+sizeof(MemTail),1);

	if(memh) {
		make_memhead_header(memh, len, str);
		return (++memh);
	}
	print_error("Calloc returns nill: len=%d in %s, total %u\n",len, str, mem_in_use);
	return 0;
}

/* note; mmap returns zero'd memory */
void *MEM_mapallocN(unsigned int len, const char *str)
{
#if defined(AMIGA) || defined(__BeOS) || defined(WIN32)
	return MEM_callocN(len, str);
#else
	MemHead *memh;
	
	len = (len + 3 ) & ~3; 	/* allocate in units of 4 */
	
#ifdef __sgi
	{
#include <fcntl.h>

	  int fd;
	  fd = open("/dev/zero", O_RDWR);

	  memh= mmap(0, len+sizeof(MemHead)+sizeof(MemTail),
		     PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	  close(fd);
	}
#else
	memh= mmap(0, len+sizeof(MemHead)+sizeof(MemTail),
		   PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANON, -1, 0);
#endif

	if(memh!=(MemHead *)-1) {
		make_memhead_header(memh, len, str);
		memh->mmap= 1;
		mmap_in_use += len;
		return (++memh);
	}
	else {
		print_error("Mapalloc returns nill, fallback to regular malloc: len=%d in %s, total %u\n",len, str, mmap_in_use);
		return MEM_callocN(len, str);
	}
	return NULL;
#endif
}


void MEM_printmemlist()
{
	MemHead *membl;

	membl = membase->first;
	if (membl) membl = MEMNEXT(membl);
	while(membl) {
		print_error("%s len: %d %p\n",membl->name,membl->len, membl+1);
		if(membl->next)
			membl= MEMNEXT(membl->next);
		else break;
	}
}

short MEM_freeN(void *vmemh)		/* anders compileertie niet meer */
{
	short error = 0;
	MemTail *memt;
	MemHead *memh= vmemh;
	const char *name;

	if (memh == NULL){
		MemorY_ErroR("free","attempt to free NULL pointer");
		/* print_error(err_stream, "%d\n", (memh+4000)->tag1); */
		return(-1);
	}

	if(sizeof(long)==8) {
		if (((long) memh) & 0x7) {
			MemorY_ErroR("free","attempt to free illegal pointer");
			return(-1);
		}
	}
	else {
		if (((long) memh) & 0x3) {
			MemorY_ErroR("free","attempt to free illegal pointer");
			return(-1);
		}
	}
	
	memh--;
	if(memh->tag1 == MEMFREE && memh->tag2 == MEMFREE) {
		MemorY_ErroR(memh->name,"double free");
		return(-1);
	}

	if ((memh->tag1 == MEMTAG1) && (memh->tag2 == MEMTAG2) && ((memh->len & 0x3) == 0)) {
		memt = (MemTail *)(((char *) memh) + sizeof(MemHead) + memh->len);
		if (memt->tag3 == MEMTAG3){
			
			memh->tag1 = MEMFREE;
			memh->tag2 = MEMFREE;
			memt->tag3 = MEMFREE;
			/* after tags !!! */
			rem_memblock(memh);
			
			return(0);
		}
		error = 2;
		MemorY_ErroR(memh->name,"end corrupt");
		name = check_memlist(memh);
		if (name != 0){
			if (name != memh->name) MemorY_ErroR(name,"is also corrupt");
		}
	} else{
		error = -1;
		name = check_memlist(memh);
		if (name == 0) MemorY_ErroR("free","pointer not in memlist");
		else MemorY_ErroR(name,"error in header");
	}

	totblock--;
	/* here a DUMP should happen */

	return(error);
}

/* --------------------------------------------------------------------- */
/* local functions                                                       */
/* --------------------------------------------------------------------- */

static void addtail(volatile localListBase *listbase, void *vlink)
{
	struct localLink *link= vlink;

	if (link == 0) return;
	if (listbase == 0) return;

	link->next = 0;
	link->prev = listbase->last;

	if (listbase->last) ((struct localLink *)listbase->last)->next = link;
	if (listbase->first == 0) listbase->first = link;
	listbase->last = link;
}

static void remlink(volatile localListBase *listbase, void *vlink)
{
	struct localLink *link= vlink;

	if (link == 0) return;
	if (listbase == 0) return;

	if (link->next) link->next->prev = link->prev;
	if (link->prev) link->prev->next = link->next;

	if (listbase->last == link) listbase->last = link->prev;
	if (listbase->first == link) listbase->first = link->next;
}

static void rem_memblock(MemHead *memh)
{
    remlink(membase,&memh->next);
    if (memh->prev){
        if (memh->next) MEMNEXT(memh->prev)->nextname = 
MEMNEXT(memh->next)->name;
        else MEMNEXT(memh->prev)->nextname = 0;
    }

    totblock--;
    mem_in_use -= memh->len;
   
#if defined(AMIGA) || defined(__BeOS) || defined(WIN32)
    free(memh);
#else   
   
    if(memh->mmap) {
        mmap_in_use -= memh->len;
        if (munmap(memh, memh->len + sizeof(MemHead) + sizeof(MemTail)))
            printf("Couldn't unmap memory %s\n", memh->name);
    }
    else   
        free(memh);
#endif
}

static void MemorY_ErroR(const char *block, const char *error)
{
	print_error("Memoryblock %s: %s\n",block, error);
}

static const char *check_memlist(MemHead *memh)
{
	MemHead *forw,*back,*forwok,*backok;
	const char *name;

	forw = membase->first;
	if (forw) forw = MEMNEXT(forw);
	forwok = 0;
	while(forw){
		if (forw->tag1 != MEMTAG1 || forw->tag2 != MEMTAG2) break;
		forwok = forw;
		if (forw->next) forw = MEMNEXT(forw->next);
		else forw = 0;
	}

	back = (MemHead *) membase->last;
	if (back) back = MEMNEXT(back);
	backok = 0;
	while(back){
		if (back->tag1 != MEMTAG1 || back->tag2 != MEMTAG2) break;
		backok = back;
		if (back->prev) back = MEMNEXT(back->prev);
		else back = 0;
	}

	if (forw != back) return ("MORE THAN 1 MEMORYBLOCK CORRUPT");

	if (forw == 0 && back == 0){
		/* geen foute headers gevonden dan maar op zoek naar memblock*/

		forw = membase->first;
		if (forw) forw = MEMNEXT(forw);
		forwok = 0;
		while(forw){
			if (forw == memh) break;
			if (forw->tag1 != MEMTAG1 || forw->tag2 != MEMTAG2) break;
			forwok = forw;
			if (forw->next) forw = MEMNEXT(forw->next);
			else forw = 0;
		}
		if (forw == 0) return (0);

		back = (MemHead *) membase->last;
		if (back) back = MEMNEXT(back);
		backok = 0;
		while(back){
			if (back == memh) break;
			if (back->tag1 != MEMTAG1 || back->tag2 != MEMTAG2) break;
			backok = back;
			if (back->prev) back = MEMNEXT(back->prev);
			else back = 0;
		}
	}

	if (forwok) name = forwok->nextname;
	else name = "No name found";

	if (forw == memh){
		/* voor alle zekerheid wordt dit block maar uit de lijst gehaald */
		if (forwok){
			if (backok){
				forwok->next = (MemHead *)&backok->next;
				backok->prev = (MemHead *)&forwok->next;
				forwok->nextname = backok->name;
			} else{
				forwok->next = 0;
  				membase->last = (struct localLink *) &forwok->next; 
/*  				membase->last = (struct Link *) &forwok->next; */
			}
		} else{
			if (backok){
				backok->prev = 0;
				membase->first = &backok->next;
			} else{
				membase->first = membase->last = 0;
			}
		}
	} else{
		MemorY_ErroR(name,"Additional error in header");
		return("Additional error in header");
	}

	return(name);
}

/* eof */