oskit/oskit-20020317/lmm/lmm_alloc.c

78 lines
2.0 KiB
C
Executable File

/*
* Copyright (c) 1995-1996, 1998-1999 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit 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 GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
#include "lmm.h"
void *lmm_alloc(lmm_t *lmm, oskit_size_t size, lmm_flags_t flags)
{
struct lmm_region *reg;
assert(lmm != 0);
assert(size > 0);
size = (size + ALIGN_MASK) & ~ALIGN_MASK;
for (reg = lmm->regions; reg; reg = reg->next)
{
struct lmm_node **nodep, *node;
CHECKREGPTR(reg);
if (flags & ~reg->flags)
continue;
for (nodep = &reg->nodes;
(node = *nodep) != 0;
nodep = &node->next)
{
assert(((oskit_addr_t)node & ALIGN_MASK) == 0);
assert(((oskit_addr_t)node->size & ALIGN_MASK) == 0);
assert((node->next == 0) || (node->next > node));
assert((oskit_addr_t)node < reg->max);
if (node->size >= size)
{
if (node->size > size)
{
struct lmm_node *newnode;
/* Split the node and return its head */
newnode = (struct lmm_node*)
((void*)node + size);
newnode->next = node->next;
newnode->size = node->size - size;
*nodep = newnode;
}
else
{
/* Remove and return the entire node. */
*nodep = node->next;
}
/* Adjust the region's free memory counter. */
assert(reg->free >= size);
reg->free -= size;
return (void*)node;
}
}
}
return 0;
}