131 lines
4.1 KiB
C++
131 lines
4.1 KiB
C++
/*************************************************************************
|
|
* *
|
|
* Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. *
|
|
* All rights reserved. Email: russ@q12.org Web: www.q12.org *
|
|
* *
|
|
* This library is free software; you can redistribute it and/or *
|
|
* modify it under the terms of EITHER: *
|
|
* (1) The GNU Lesser General Public License as published by the Free *
|
|
* Software Foundation; either version 2.1 of the License, or (at *
|
|
* your option) any later version. The text of the GNU Lesser *
|
|
* General Public License is included with this library in the *
|
|
* file LICENSE.TXT. *
|
|
* (2) The BSD-style license that is included with this library in *
|
|
* the file LICENSE-BSD.TXT. *
|
|
* *
|
|
* This library is distributed in the hope that it will be useful, *
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files *
|
|
* LICENSE.TXT and LICENSE-BSD.TXT for more details. *
|
|
* *
|
|
*************************************************************************/
|
|
|
|
#include <ode/common.h>
|
|
#include <ode/error.h>
|
|
#include <ode/memory.h>
|
|
#include "obstack.h"
|
|
|
|
//****************************************************************************
|
|
// macros and constants
|
|
|
|
#define ROUND_UP_OFFSET_TO_EFFICIENT_SIZE(arena,ofs) \
|
|
ofs = (size_t) (dEFFICIENT_SIZE( ((intP)(arena)) + ofs ) - ((intP)(arena)) );
|
|
|
|
#define MAX_ALLOC_SIZE \
|
|
((size_t)(dOBSTACK_ARENA_SIZE - sizeof (Arena) - EFFICIENT_ALIGNMENT + 1))
|
|
|
|
//****************************************************************************
|
|
// dObStack
|
|
|
|
dObStack::dObStack()
|
|
{
|
|
first = 0;
|
|
last = 0;
|
|
current_arena = 0;
|
|
current_ofs = 0;
|
|
}
|
|
|
|
|
|
dObStack::~dObStack()
|
|
{
|
|
// free all arenas
|
|
Arena *a,*nexta;
|
|
a = first;
|
|
while (a) {
|
|
nexta = a->next;
|
|
dFree (a,dOBSTACK_ARENA_SIZE);
|
|
a = nexta;
|
|
}
|
|
}
|
|
|
|
|
|
void *dObStack::alloc (int num_bytes)
|
|
{
|
|
if ((size_t)num_bytes > MAX_ALLOC_SIZE) dDebug (0,"num_bytes too large");
|
|
|
|
// allocate or move to a new arena if necessary
|
|
if (!first) {
|
|
// allocate the first arena if necessary
|
|
first = last = (Arena *) dAlloc (dOBSTACK_ARENA_SIZE);
|
|
first->next = 0;
|
|
first->used = sizeof (Arena);
|
|
ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (first,first->used);
|
|
}
|
|
else {
|
|
// we already have one or more arenas, see if a new arena must be used
|
|
if ((last->used + num_bytes) > dOBSTACK_ARENA_SIZE) {
|
|
if (!last->next) {
|
|
last->next = (Arena *) dAlloc (dOBSTACK_ARENA_SIZE);
|
|
last->next->next = 0;
|
|
}
|
|
last = last->next;
|
|
last->used = sizeof (Arena);
|
|
ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (last,last->used);
|
|
}
|
|
}
|
|
|
|
// allocate an area in the arena
|
|
char *c = ((char*) last) + last->used;
|
|
last->used += num_bytes;
|
|
ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (last,last->used);
|
|
return c;
|
|
}
|
|
|
|
|
|
void dObStack::freeAll()
|
|
{
|
|
last = first;
|
|
if (first) {
|
|
first->used = sizeof(Arena);
|
|
ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (first,first->used);
|
|
}
|
|
}
|
|
|
|
|
|
void *dObStack::rewind()
|
|
{
|
|
current_arena = first;
|
|
current_ofs = sizeof (Arena);
|
|
if (current_arena) {
|
|
ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (current_arena,current_ofs)
|
|
return ((char*) current_arena) + current_ofs;
|
|
}
|
|
else return 0;
|
|
}
|
|
|
|
|
|
void *dObStack::next (int num_bytes)
|
|
{
|
|
// this functions like alloc, except that no new storage is ever allocated
|
|
if (!current_arena) return 0;
|
|
current_ofs += num_bytes;
|
|
ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (current_arena,current_ofs);
|
|
if (current_ofs >= current_arena->used) {
|
|
current_arena = current_arena->next;
|
|
if (!current_arena) return 0;
|
|
current_ofs = sizeof (Arena);
|
|
ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (current_arena,current_ofs);
|
|
}
|
|
return ((char*) current_arena) + current_ofs;
|
|
}
|