/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2011 AT&T Intellectual Property *
* and is licensed under the *
* Eclipse Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.eclipse.org/org/documents/epl-v10.html *
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* standalone mini vmalloc implementation
* no resize, no free, no disciplines, no methods
*/
#include <ast.h>
#include <vmalloc.h>
Vmalloc_t* Vmregion;
Vmalloc_t*
_vm_open(void)
{
Vmalloc_t* vp;
if (vp = newof(0, Vmalloc_t, 1, 0))
{
vp->current = &vp->base;
vp->data = vp->current->data;
vp->size = sizeof(vp->current->data);
}
return vp;
}
int
_vm_close(register Vmalloc_t* vp)
{
register Vmchunk_t* cp;
register Vmchunk_t* np;
if (!vp)
return -1;
np = vp->base.next;
while (cp = np)
{
np = cp->next;
free(cp);
}
free(vp);
return 0;
}
void*
_vm_resize(register Vmalloc_t* vp, void* o, unsigned long size)
{
char* p;
unsigned long n;
unsigned long z;
z = vp->last;
vp->last = size;
if (o && size < z)
return o;
if ((o ? (size - z) : size) > vp->size)
{
n = (size > sizeof(vp->current->data)) ? (size - sizeof(vp->current->data)) : 0;
if (!(vp->current->next = newof(0, Vmchunk_t, 1, n)))
return 0;
vp->current = vp->current->next;
vp->data = vp->current->data;
vp->size = n ? 0 : sizeof(vp->current->data);
if (o)
{
memcpy(vp->data, o, z);
o = (void*)vp->data;
}
}
else if (o)
size -= z;
p = vp->data;
size = roundof(size, VM_ALIGN);
if (size >= vp->size)
vp->size = 0;
else
{
vp->size -= size;
vp->data += size;
}
return p;
}