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Diffstat (limited to 'dmake/dbug/malloc/realloc.c')
| -rw-r--r-- | dmake/dbug/malloc/realloc.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/dmake/dbug/malloc/realloc.c b/dmake/dbug/malloc/realloc.c new file mode 100644 index 000000000000..2801cd86212d --- /dev/null +++ b/dmake/dbug/malloc/realloc.c @@ -0,0 +1,180 @@ +/* + * (c) Copyright 1990 Conor P. Cahill (uunet!virtech!cpcahil). + * You may copy, distribute, and use this software as long as this + * copyright statement is not removed. + */ +#include <stdio.h> +#include "malloc.h" + +/* + * Function: realloc() + * + * Purpose: to re-allocate a data area. + * + * Arguments: cptr - pointer to area to reallocate + * size - size to change area to + * + * Returns: pointer to new area (may be same area) + * + * Narrative: verify pointer is within malloc region + * obtain mlist pointer from cptr + * verify magic number is correct + * verify inuse flag is set + * verify connection to adjoining segments is correct + * save requested size + * round-up size to appropriate boundry + * IF size is bigger than what is in this segment + * try to join next segment to this segment + * IF size is less than what is is this segment + * determine leftover amount of space + * ELSE + * allocate new segment of size bites + * IF allocation failed + * return NULL + * copy previous data to new segment + * free previous segment + * return new pointer + * split of extra space in this segment (if any) + * clear bytes beyound what they had before + * return pointer to data + */ +#ifndef lint +static +char rcs_hdr[] = "$Id: realloc.c,v 1.2 2006-07-25 10:09:48 rt Exp $"; +#endif + +char * +realloc(cptr,size) + char * cptr; + unsigned int size; +{ + void free(); + char * func = "realloc"; + int i; + char * malloc(); + extern int malloc_checking; + extern struct mlist * malloc_end; + extern int malloc_errno; + extern char * malloc_data_end; + extern char * malloc_data_start; + void malloc_join(); + void malloc_memset(); + void malloc_split(); + char * memcpy(); + char * new_cptr; + struct mlist * ptr; + int r_size; + + /* + * IF malloc chain checking is on, go do it. + */ + if( malloc_checking ) + { + (void) malloc_chain_check(1); + } + + /* + * verify that cptr is within the malloc region... + */ + if( cptr < malloc_data_start || cptr > malloc_data_end ) + { + malloc_errno = M_CODE_BAD_PTR; + malloc_warning(func); + return (NULL); + } + + /* + * convert pointer to mlist struct pointer. To do this we must + * move the pointer backwards the correct number of bytes... + */ + + ptr = (struct mlist *) (cptr - M_SIZE); + + if( (ptr->flag&M_MAGIC) != M_MAGIC ) + { + malloc_errno = M_CODE_BAD_MAGIC; + malloc_warning(func); + return(NULL); + } + + if( ! (ptr->flag & M_INUSE) ) + { + malloc_errno = M_CODE_NOT_INUSE ; + malloc_warning(func); + return(NULL); + } + + if( (ptr->prev && (ptr->prev->next != ptr) ) || + (ptr->next && (ptr->next->prev != ptr) ) || + ((ptr->next == NULL) && (ptr->prev == NULL)) ) + { + malloc_errno = M_CODE_BAD_CONNECT; + malloc_warning(func); + return(NULL); + } + + r_size = ++size; + + M_ROUNDUP(size); + + if( size > ptr->s.size ) + { + malloc_join(ptr,ptr->next,1,1); + } + + if( size > ptr->s.size ) + { + /* + * else we can't combine it, so lets allocate a new chunk, + * copy the data and free the old chunk... + */ + new_cptr = malloc(size); + + if( new_cptr == (char *) 0) + { + return(new_cptr); + } + + if( r_size < ptr->r_size ) + { + i = r_size; + } + else + { + i = ptr->r_size; + } + (void)memcpy(new_cptr,ptr->data,i); + free(cptr); + return(new_cptr); + + } /* else... */ + + /* + * save amount of real data in new segment (this will be used in the + * memset later) and then save requested size of this segment. + */ + + if( ptr->r_size < r_size ) + { + i = ptr->r_size; + } + else + { + i = r_size; + } + + ptr->r_size = r_size; + + /* + * split off extra free space at end of this segment, if possible... + */ + + malloc_split(ptr); + + malloc_memset( ptr->data+i, M_FILL, (int) (ptr->s.size - i)); + + return(ptr->data); + +} /* realloc(... */ + + |