/* ========================================================================== */
/* === UMF_realloc ========================================================== */
/* ========================================================================== */

/* -------------------------------------------------------------------------- */
/* UMFPACK Copyright (c) Timothy A. Davis, CISE,                              */
/* Univ. of Florida.  All Rights Reserved.  See ../Doc/License for License.   */
/* web: http://www.cise.ufl.edu/research/sparse/umfpack                       */
/* -------------------------------------------------------------------------- */

/*
    Realloc a block previously allocated by UMF_malloc.
    Return NULL on failure (in which case the block is still allocated, and will
    be kept at is present size).  This routine is only used for Numeric->Memory.
*/

#include "umf_internal.h"

#if defined (UMF_MALLOC_COUNT) || !defined (NDEBUG)
#include "umf_malloc.h"
#endif

GLOBAL void *UMF_realloc
(
    void *p,
    Int n_objects,
    size_t size_of_object
)
{
    size_t size ;
    void *p2 ;

#ifdef UMF_TCOV_TEST
    /* For exhaustive statement coverage testing only! */
    /* Pretend to fail, to test out-of-memory conditions. */
    umf_realloc_fail-- ;
    if (umf_realloc_fail <= umf_realloc_hi &&
	umf_realloc_fail >= umf_realloc_lo)
    {
	return ((void *) NULL) ;
    }
#endif

    /* make sure that we allocate something */
    n_objects = MAX (1, n_objects) ;

    size = (size_t) n_objects ;
    ASSERT (size_of_object > 1) ;
    if (size > Int_MAX / size_of_object)
    {
	/* :: int overflow in umf_realloc :: */
	return ((void *) NULL) ;
    }
    size *= size_of_object ;

    DEBUG0 (("UMF_realloc: "ID" n_objects "ID"  size_of_object "ID"\n",
	(Int) p, n_objects, (Int) size_of_object)) ;

    /* see AMD/Source/amd_global.c for the memory allocator selection */
    p2 = amd_realloc (p, size) ;

#if defined (UMF_MALLOC_COUNT) || !defined (NDEBUG)
    /* If p didn't exist on input, and p2 exists, then a new object has been
     * allocated. */
    if (p == (void *) NULL && p2 != (void *) NULL)
    {
	UMF_malloc_count++ ;
    }
#endif

    DEBUG0 (("UMF_realloc: "ID" new malloc count "ID"\n",
	(Int) p2, UMF_malloc_count)) ;

    return (p2) ;
}