tomwalters@0: /*
tomwalters@0:     wrap.c
tomwalters@0:     ======
tomwalters@0: 
tomwalters@0:     encapsulate memory allocation for debugging en masse.
tomwalters@0: 
tomwalters@0: */
tomwalters@0: 
tomwalters@0: #include "stitch.h"
tomwalters@0: #include "wrap.h"
tomwalters@0: 
tomwalters@0: #define LOGGING
tomwalters@0: 
tomwalters@0: /* linked list of framed allocations */
tomwalters@0: 
tomwalters@0: static struct _head *lastAllocated = (struct _head *) 0 ;
tomwalters@0: 
tomwalters@0: 
tomwalters@0: static void wraperr( id, hsz, tsz )
tomwalters@0: char *id ;
tomwalters@0: unsigned hsz, tsz ;
tomwalters@0: {
tomwalters@0:     printf( "memerr %s %d %d\n", id, hsz, tsz ) ;
tomwalters@0: }
tomwalters@0: 
tomwalters@0: 
tomwalters@0: Pointer wrap( mem, size, where )
tomwalters@0: char *mem ;
tomwalters@0: unsigned size ;
tomwalters@0: char where[] ;
tomwalters@0: {
tomwalters@0:     register struct _head *head = (struct _head *) mem ;
tomwalters@0:     register Pointer wrapped    = (Address) head + ROUNDUP( sizeof ( *head ) ) ;
tomwalters@0:     register struct _tail *tail = (struct _tail *) ( (Address) wrapped + ROUNDUP( size ) ) ;
tomwalters@0: 
tomwalters@0: #ifdef LOGGING
tomwalters@0:     (void) printf( "wrapping %x, %d bytes in %s\n", mem, size, where ) ;
tomwalters@0: #endif
tomwalters@0: 
tomwalters@0:     head->where = where ;
tomwalters@0:     head->size  = size  ;
tomwalters@0: 
tomwalters@0:     tail->size  = size  ;
tomwalters@0: 
tomwalters@0:     head->previous =  lastAllocated ;
tomwalters@0: 
tomwalters@0:     if( lastAllocated != 0 )
tomwalters@0: 	lastAllocated->pointing = &head->previous ;
tomwalters@0: 
tomwalters@0:     lastAllocated = head ;
tomwalters@0:     lastAllocated->pointing = &lastAllocated ;
tomwalters@0: 
tomwalters@0:     return ( wrapped ) ;
tomwalters@0: }
tomwalters@0: 
tomwalters@0: 
tomwalters@0: Pointer unwrap( wrapped )
tomwalters@0: Pointer wrapped ;
tomwalters@0: {
tomwalters@0:     register struct _head *head = (struct _head *) ( (Address) wrapped - ROUNDUP( sizeof ( *head ) ) ) ;
tomwalters@0:     register struct _tail *tail = (struct _tail *) ( (Address) wrapped + ROUNDUP( head->size ) ) ;
tomwalters@0: 
tomwalters@0: #ifdef LOGGING
tomwalters@0:     (void) printf( "unwrapping %x, %d bytes in %s\n", head, head->size, head->where ) ;
tomwalters@0: #endif
tomwalters@0: 
tomwalters@0:     if( head->size != tail->size )
tomwalters@0: 	wraperr( head->where, head->size, tail->size ) ;
tomwalters@0: 
tomwalters@0:     *head->pointing = head->previous ;
tomwalters@0: 
tomwalters@0:     if( head->previous != (struct _head *) 0 )
tomwalters@0: 	head->previous->pointing = head->pointing ;
tomwalters@0: 
tomwalters@0:     return ( (char *) head ) ;
tomwalters@0: }
tomwalters@0: 
tomwalters@0: check_wrapping( printer )
tomwalters@0: {
tomwalters@0:     register struct _head *head = lastAllocated ;
tomwalters@0:     register Pointer wrapped ;
tomwalters@0:     register struct _tail *tail ;
tomwalters@0: 
tomwalters@0:     while( head != (struct _head *) 0 ) {
tomwalters@0: 
tomwalters@0: 	wrapped = (Pointer) ( head + 1 ) ;
tomwalters@0: 
tomwalters@0: 	tail = ( struct _tail * ) ( (Address) wrapped + ROUNDUP( head->size ) ) ;
tomwalters@0: 
tomwalters@0: 	if( tail->size != head->size )
tomwalters@0: 	    wraperr( head->where, head->size, tail->size ) ;
tomwalters@0: 
tomwalters@0: 	head = head->previous ;
tomwalters@0:     }
tomwalters@0: 
tomwalters@0:     return ;
tomwalters@0: }
tomwalters@0: 
tomwalters@0: print_wrapping()
tomwalters@0: {
tomwalters@0:     register struct _head *head = lastAllocated ;
tomwalters@0:     register Pointer wrapped ;
tomwalters@0:     register struct _tail *tail ;
tomwalters@0: 
tomwalters@0:     while( head != (struct _head *) 0 ) {
tomwalters@0: 
tomwalters@0: 	wrapped = (Pointer) ( head + 1 ) ;
tomwalters@0: 
tomwalters@0: 	tail = (struct _tail *) ( (Address) wrapped + ROUNDUP( head->size ) ) ;
tomwalters@0: 
tomwalters@0: printf( "%d bytes \"%s\"\n", head->size, head->where ) ;
tomwalters@0: 	if( tail->size != head->size )
tomwalters@0: 	    wraperr( head->where, head->size, tail->size ) ;
tomwalters@0: 
tomwalters@0: 	head = head->previous ;
tomwalters@0:     }
tomwalters@0: 
tomwalters@0: printf( "\n" ) ;
tomwalters@0: 
tomwalters@0:     return ;
tomwalters@0: }
tomwalters@0: