1/***********************************************************************
2*                                                                      *
3*               This software is part of the ast package               *
4*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5*                      and is licensed under the                       *
6*                 Eclipse Public License, Version 1.0                  *
7*                    by AT&T Intellectual Property                     *
8*                                                                      *
9*                A copy of the License is available at                 *
10*          http://www.eclipse.org/org/documents/epl-v10.html           *
11*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
12*                                                                      *
13*              Information and Software Systems Research               *
14*                            AT&T Research                             *
15*                           Florham Park NJ                            *
16*                                                                      *
17*                 Glenn Fowler <gsf@research.att.com>                  *
18*                  David Korn <dgk@research.att.com>                   *
19*                   Phong Vo <kpv@research.att.com>                    *
20*                                                                      *
21***********************************************************************/
22#pragma prototyped
23/*
24 * standalone mini vmalloc implementation
25 * no resize, no free, no disciplines, no methods
26 */
27
28#include <ast.h>
29#include <vmalloc.h>
30
31Vmalloc_t*	Vmregion;
32
33Vmalloc_t*
34_vm_open(void)
35{
36	Vmalloc_t*	vp;
37
38	if (vp = newof(0, Vmalloc_t, 1, 0))
39	{
40		vp->current = &vp->base;
41		vp->data = vp->current->data;
42		vp->size = sizeof(vp->current->data);
43	}
44	return vp;
45}
46
47int
48_vm_close(register Vmalloc_t* vp)
49{
50	register Vmchunk_t*	cp;
51	register Vmchunk_t*	np;
52
53	if (!vp)
54		return -1;
55	np = vp->base.next;
56	while (cp = np)
57	{
58		np = cp->next;
59		free(cp);
60	}
61	free(vp);
62	return 0;
63}
64
65void*
66_vm_resize(register Vmalloc_t* vp, void* o, unsigned long size)
67{
68	char*		p;
69	unsigned long	n;
70	unsigned long	z;
71
72	z = vp->last;
73	vp->last = size;
74	if (o && size < z)
75		return o;
76	if ((o ? (size - z) : size) > vp->size)
77	{
78		n = (size > sizeof(vp->current->data)) ? (size - sizeof(vp->current->data)) : 0;
79		if (!(vp->current->next = newof(0, Vmchunk_t, 1, n)))
80			return 0;
81		vp->current = vp->current->next;
82		vp->data = vp->current->data;
83		vp->size = n ? 0 : sizeof(vp->current->data);
84		if (o)
85		{
86			memcpy(vp->data, o, z);
87			o = (void*)vp->data;
88		}
89	}
90	else if (o)
91		size -= z;
92	p = vp->data;
93	size = roundof(size, VM_ALIGN);
94	if (size >= vp->size)
95		vp->size = 0;
96	else
97	{
98		vp->size -= size;
99		vp->data += size;
100	}
101	return p;
102}
103