/**

 * @file    papi_memory.c

 * @author  Kevin London

 *          london@cs.utk.edu

 * PAPI memory allocation provides for checking and maintenance of all memory

 * allocated through this interface. Implemented as a series of wrappers around

 * standard C memory allocation routines, _papi_malloc and associated functions

 * add a prolog and optional epilog to each malloc'd pointer.

 * The prolog, sized to preserve memory alignment, contains a pointer to a 

 * linked list of pmem_t structures that describe every block of memory 

 * allocated through these calls.

 * The optional epilog is enabled if DEBUG is defined, and contains 

 * a distinctive pattern that allows checking for pointer overflow.

 */

#define IN_MEM_FILE

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "papi.h"

#include "papi_lock.h"

#include "papi_memory.h"

#include "papi_internal.h"

/** Define the amount of extra memory at the beginning of the alloc'd pointer.

 * This is usually the size of a pointer, but in some cases needs to be bigger

 * to preserve data alignment.

 */

#define MEM_PROLOG (2*sizeof(void *))

/* If you are tracing memory, then DEBUG must be set also. */

#ifdef DEBUG

/** Define the amount of extra memory at the end of the alloc'd pointer.

 * Also define the contents: 0xCACA

 */

#define MEM_EPILOG 4

#define MEM_EPILOG_1 0xC

#define MEM_EPILOG_2 0xA

#define MEM_EPILOG_3 0xC

#define MEM_EPILOG_4 0xA

#endif

/* Local global variables */

static pmem_t *mem_head = NULL;

/* Local Prototypes */

static pmem_t *get_mem_ptr( void *ptr );

static pmem_t *init_mem_ptr( void *, int, char *, int );

static void insert_mem_ptr( pmem_t * );

static void remove_mem_ptr( pmem_t * );

static int set_epilog( pmem_t * mem_ptr );

/**********************************************************************

 * Exposed papi versions of std memory management routines:           *

 *  _papi_realloc                                                     *

 *  _papi_calloc                                                      *

 *  _papi_malloc                                                      *

 *  _papi_strdup                                                      *

 *  _papi_free                                                        *

 *  _papi_valid_free                                                  *

 * Exposed useful papi memory maintenance routines:                   *

 *  _papi_mem_print_info                                              *

 *  _papi_mem_print_stats                                             *

 *  _papi_mem_overhead                                                *

 *  _papi_mem_cleanup_all                                             *

 *  _papi_mem_check_buf_overflow                                      *

 *  _papi_mem_check_all_overflow                                      *

 **********************************************************************/

/** _papi_realloc -- given a pointer returned by _papi_malloc, returns a pointer

 * to the related pmem_t structure describing this pointer.

 * Checks for NULL pointers and returns NULL if error.

 */

void *

_papi_realloc( char *file, int line, void *ptr, size_t size )

{

	size_t nsize = size + MEM_PROLOG;

	pmem_t *mem_ptr;

	void *nptr;

#ifdef DEBUG

	nsize += MEM_EPILOG;

	_papi_hwi_lock( MEMORY_LOCK );

	_papi_mem_check_all_overflow(  );

#endif

	if ( !ptr )

		return ( _papi_malloc( file, line, size ) );

	mem_ptr = get_mem_ptr( ptr );

	nptr = ( pmem_t * ) realloc( ( ( char * ) ptr - MEM_PROLOG ), nsize );

	if ( !nptr )

		return ( NULL );

	mem_ptr->size = ( int ) size;

	mem_ptr->ptr = ( char * ) nptr + MEM_PROLOG;

#ifdef DEBUG

	strncpy( mem_ptr->file, file, DEBUG_FILE_LEN );

	mem_ptr->file[DEBUG_FILE_LEN - 1] = '\0';

	mem_ptr->line = line;

	set_epilog( mem_ptr );

	_papi_hwi_unlock( MEMORY_LOCK );

#endif

	MEMDBG( "%p: Re-allocated: %lu bytes from File: %s  Line: %d\n",

			mem_ptr->ptr, ( unsigned long ) size, file, line );

	return ( mem_ptr->ptr );

}

void *

_papi_calloc( char *file, int line, size_t nmemb, size_t size )

{

	void *ptr = _papi_malloc( file, line, size * nmemb );

	if ( !ptr )

		return ( NULL );

	memset( ptr, 0, size * nmemb );

	return ( ptr );

}

void *

_papi_malloc( char *file, int line, size_t size )

{

	void *ptr;

	void **tmp;

	pmem_t *mem_ptr;

	size_t nsize = size + MEM_PROLOG;

#ifdef DEBUG

	nsize += MEM_EPILOG;

#endif

	if ( size == 0 ) {

		MEMDBG( "Attempting to allocate %lu bytes from File: %s  Line: %d\n",

				( unsigned long ) size, file, line );

		return ( NULL );

	}

	ptr = ( void * ) malloc( nsize );

	if ( !ptr )

		return ( NULL );

	else {

		if ( ( mem_ptr =

			   init_mem_ptr( ( char * ) ptr + MEM_PROLOG, ( int ) size, file,

							 line ) ) == NULL ) {

			free( ptr );

			return ( NULL );

		}

		tmp = ptr;

		*tmp = mem_ptr;

		ptr = mem_ptr->ptr;

		mem_ptr->ptr = ptr;

		_papi_hwi_lock( MEMORY_LOCK );

		insert_mem_ptr( mem_ptr );

		set_epilog( mem_ptr );

		_papi_hwi_unlock( MEMORY_LOCK );

		MEMDBG( "%p: Allocated %lu bytes from File: %s  Line: %d\n",

				mem_ptr->ptr, ( unsigned long ) size, file, line );

		return ( ptr );

	}

	return ( NULL );

}

char *

_papi_strdup( char *file, int line, const char *s )

{

	size_t size;

	char *ptr;

	if ( !s )

		return ( NULL );

	/* String Length +1 for \0 */

	size = strlen( s ) + 1;

	ptr = ( char * ) _papi_malloc( file, line, size );

	if ( !ptr )

		return ( NULL );

	memcpy( ptr, s, size );

	return ( ptr );

}

/** Only frees the memory if PAPI malloced it 

  * returns 1 if pointer was valid; 0 if not */

int

_papi_valid_free( char *file, int line, void *ptr )

{

	pmem_t *tmp;

	int valid = 0;

	if ( !ptr ) {

		( void ) file;

		( void ) line;

		return ( 0 );

	}

	_papi_hwi_lock( MEMORY_LOCK );

	for ( tmp = mem_head; tmp; tmp = tmp->next ) {

		if ( ptr == tmp->ptr ) {

			pmem_t *mem_ptr = get_mem_ptr( ptr );

			if ( mem_ptr ) {

				MEMDBG( "%p: Freeing %d bytes from File: %s  Line: %d\n",

						mem_ptr->ptr, mem_ptr->size, file, line );

				remove_mem_ptr( mem_ptr );

				_papi_mem_check_all_overflow(  );

			}

			valid = 1;

			break;

		}

	}

	_papi_hwi_unlock( MEMORY_LOCK );

	return ( valid );

}

/** Frees up the ptr */

void

_papi_free( char *file, int line, void *ptr )

{

	pmem_t *mem_ptr = get_mem_ptr( ptr );

	if ( !mem_ptr ) {

		( void ) file;

		( void ) line;

		return;

	}

	MEMDBG( "%p: Freeing %d bytes from File: %s  Line: %d\n", mem_ptr->ptr,

			mem_ptr->size, file, line );

	_papi_hwi_lock( MEMORY_LOCK );

	remove_mem_ptr( mem_ptr );

	_papi_mem_check_all_overflow(  );

	_papi_hwi_unlock( MEMORY_LOCK );

}

/** Print information about the memory including file and location it came from */

void

_papi_mem_print_info( void *ptr )

{

	pmem_t *mem_ptr = get_mem_ptr( ptr );

#ifdef DEBUG

	fprintf( stderr, "%p: Allocated %d bytes from File: %s  Line: %d\n", ptr,

			 mem_ptr->size, mem_ptr->file, mem_ptr->line );

#else

	fprintf( stderr, "%p: Allocated %d bytes\n", ptr, mem_ptr->size );

#endif

	return;

}

/** Print out all memory information */

void

_papi_mem_print_stats(  )

{

	pmem_t *tmp = NULL;

	_papi_hwi_lock( MEMORY_LOCK );

	for ( tmp = mem_head; tmp; tmp = tmp->next ) {

		_papi_mem_print_info( tmp->ptr );

	}

	_papi_hwi_unlock( MEMORY_LOCK );

}

/** Return the amount of memory overhead of the PAPI library and the memory system

 * PAPI_MEM_LIB_OVERHEAD is the library overhead

 * PAPI_MEM_OVERHEAD is the memory overhead

 * They both can be | together

 * This only includes "malloc'd memory"

 */

int

_papi_mem_overhead( int type )

{

	pmem_t *ptr = NULL;

	int size = 0;

	_papi_hwi_lock( MEMORY_LOCK );

	for ( ptr = mem_head; ptr; ptr = ptr->next ) {

		if ( type & PAPI_MEM_LIB_OVERHEAD )

			size += ptr->size;

		if ( type & PAPI_MEM_OVERHEAD ) {

			size += ( int ) sizeof ( pmem_t );

			size += ( int ) MEM_PROLOG;

#ifdef DEBUG

			size += ( int ) MEM_EPILOG;

#endif

		}

	}

	_papi_hwi_unlock( MEMORY_LOCK );

	return size;

}

/** Clean all memory up and print out memory leak information to stderr */

void

_papi_mem_cleanup_all(  )

{

	pmem_t *ptr = NULL, *tmp = NULL;

#ifdef DEBUG

	int cnt = 0;

#endif

	_papi_hwi_lock( MEMORY_LOCK );

	_papi_mem_check_all_overflow(  );

	for ( ptr = mem_head; ptr; ptr = tmp ) {

		tmp = ptr->next;

#ifdef DEBUG

		LEAKDBG( "MEMORY LEAK: %p of %d bytes, from File: %s Line: %d\n",

				 ptr->ptr, ptr->size, ptr->file, ptr->line );

		cnt += ptr->size;

#endif

		remove_mem_ptr( ptr );

	}

	_papi_hwi_unlock( MEMORY_LOCK );

#ifdef DEBUG

	if ( 0 != cnt ) { 

		LEAKDBG( "TOTAL MEMORY LEAK: %d bytes.\n", cnt );

	}

#endif

}

/* Loop through memory structures and look for buffer overflows 

 * returns the number of overflows detected

 */

/**********************************************************************

 * Private helper routines for papi memory management                 *

 **********************************************************************/

/* Given a pointer returned by _papi_malloc, returns a pointer

 * to the related pmem_t structure describing this pointer.

 * Checks for NULL pointers and returns NULL if error.

 */

static pmem_t *

get_mem_ptr( void *ptr )

{

	pmem_t **tmp_ptr = ( pmem_t ** ) ( ( char * ) ptr - MEM_PROLOG );

	pmem_t *mem_ptr;

	if ( !tmp_ptr || !ptr )

		return ( NULL );

	mem_ptr = *tmp_ptr;

	return ( mem_ptr );

}

/* Allocate and initialize a memory pointer */

pmem_t *

init_mem_ptr( void *ptr, int size, char *file, int line )

{

	pmem_t *mem_ptr = NULL;

	if ( ( mem_ptr = ( pmem_t * ) malloc( sizeof ( pmem_t ) ) ) == NULL )

		return ( NULL );

	mem_ptr->ptr = ptr;

	mem_ptr->size = size;

	mem_ptr->next = NULL;

	mem_ptr->prev = NULL;

#ifdef DEBUG

	strncpy( mem_ptr->file, file, DEBUG_FILE_LEN );

	mem_ptr->file[DEBUG_FILE_LEN - 1] = '\0';

	mem_ptr->line = line;

#else

	( void ) file;			 /*unused */

	( void ) line;			 /*unused */

#endif

	return ( mem_ptr );

}

/* Insert the memory information 

 * Do not lock these routines, but lock in routines using these

 */

static void

insert_mem_ptr( pmem_t * ptr )

{

	if ( !ptr )

		return;

	if ( !mem_head ) {

		mem_head = ptr;

		ptr->next = NULL;

		ptr->prev = NULL;

	} else {

		mem_head->prev = ptr;

		ptr->next = mem_head;

		mem_head = ptr;

	}

	return;

}

/* Remove the memory information pointer and free the memory 

 * Do not using locking in this routine, instead lock around 

 * the sections of code that use this call.

 */

static void

remove_mem_ptr( pmem_t * ptr )

{

	if ( !ptr )

		return;

	if ( ptr->prev )

		ptr->prev->next = ptr->next;

	if ( ptr->next )

		ptr->next->prev = ptr->prev;

	if ( ptr == mem_head )

		mem_head = ptr->next;

	free( ptr );

}

static int

set_epilog( pmem_t * mem_ptr )

{

#ifdef DEBUG

	char *chptr = ( char * ) mem_ptr->ptr + mem_ptr->size;

	*chptr++ = MEM_EPILOG_1;

	*chptr++ = MEM_EPILOG_2;

	*chptr++ = MEM_EPILOG_3;

	*chptr++ = MEM_EPILOG_4;

	return ( _papi_mem_check_all_overflow(  ) );

#else

	( void ) mem_ptr;		 /*unused */

#endif

	return ( 0 );

}

/* Check for memory buffer overflows */

#ifdef DEBUG

static int

_papi_mem_check_buf_overflow( pmem_t * tmp )

{

	int fnd = 0;

	char *ptr;

	char *tptr;

	if ( !tmp )

		return ( 0 );

	tptr = tmp->ptr;

	tptr += tmp->size;

	/* Move to the buffer overflow padding */

	ptr = ( ( char * ) tmp->ptr ) + tmp->size;

	if ( *ptr++ != MEM_EPILOG_1 )

		fnd = 1;

	else if ( *ptr++ != MEM_EPILOG_2 )

		fnd = 2;

	else if ( *ptr++ != MEM_EPILOG_3 )

		fnd = 3;

	else if ( *ptr++ != MEM_EPILOG_4 )

		fnd = 4;

	if ( fnd ) {

		LEAKDBG( "Buffer Overflow[%d] for %p allocated from %s at line %d\n",

				 fnd, tmp->ptr, tmp->file, tmp->line );

	}

	return ( fnd );

}

#endif

int

_papi_mem_check_all_overflow(  )

{

	int fnd = 0;

#ifdef DEBUG

	pmem_t *tmp;

	for ( tmp = mem_head; tmp; tmp = tmp->next ) {

		if ( _papi_mem_check_buf_overflow( tmp ) )

			fnd++;

	}

	if ( fnd ) {

		LEAKDBG( "%d Total Buffer overflows detected!\n", fnd );

	}

#endif

	return ( fnd );

}