1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
|
/* ========================================================================== */
/* === UMF_mem_alloc_head_block ============================================= */
/* ========================================================================== */
/* -------------------------------------------------------------------------- */
/* UMFPACK Version 4.1 (Apr. 30, 2003), Copyright (c) 2003 by Timothy A. */
/* Davis. All Rights Reserved. See ../README for License. */
/* email: davis@cise.ufl.edu CISE Department, Univ. of Florida. */
/* web: http://www.cise.ufl.edu/research/sparse/umfpack */
/* -------------------------------------------------------------------------- */
/* The UMF_mem_* routines manage the Numeric->Memory memory space. */
/* allocate nunits from head of Numeric->Memory. No header allocated. */
/* Returns the index into Numeric->Memory if successful, or 0 on failure. */
#include "umf_internal.h"
GLOBAL Int UMF_mem_alloc_head_block
(
NumericType *Numeric,
Int nunits
)
{
Int p, usage ;
DEBUG2 (("GET BLOCK: from head, size "ID" ", nunits)) ;
ASSERT (Numeric != (NumericType *) NULL) ;
ASSERT (Numeric->Memory != (Unit *) NULL) ;
#ifndef NDEBUG
if (UMF_allocfail)
{
/* pretend to fail, to test garbage_collection */
DEBUGm2 (("UMF_mem_alloc_head_block: pretend to fail\n")) ;
UMF_allocfail = FALSE ; /* don't fail the next time */
return (0) ;
}
#endif
if (nunits > (Numeric->itail - Numeric->ihead))
{
DEBUG2 ((" failed\n")) ;
return (0) ;
}
/* return p as an offset from Numeric->Memory */
p = Numeric->ihead ;
Numeric->ihead += nunits ;
DEBUG2 (("p: "ID"\n", p)) ;
usage = Numeric->ihead + Numeric->tail_usage ;
Numeric->max_usage = MAX (Numeric->max_usage, usage) ;
return (p) ;
}
|