cdesktopenv/cde/programs/nsgmls/Allocator.C

128 lines
3.0 KiB
C

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these librararies and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/* $XConsortium: Allocator.C /main/1 1996/07/29 16:45:56 cde-hp $ */
// Copyright (c) 1994 James Clark
// See the file COPYING for copying permission.
#include "splib.h"
#include "Allocator.h"
#include "macros.h"
#ifdef SP_NAMESPACE
namespace SP_NAMESPACE {
#endif
Allocator::Allocator(size_t maxSize, unsigned blocksPerSegment)
: objectSize_(maxSize),
blocksPerSegment_(blocksPerSegment),
freeList_(0),
segments_(0)
{
}
Allocator::~Allocator()
{
SegmentHeader *p = segments_;
while (p) {
SegmentHeader *tem = p->next;
if (p->liveCount == 0)
::operator delete(p);
else
p->freeList = 0;
p = tem;
}
}
void *Allocator::alloc(size_t sz)
{
if (sz > objectSize_)
tooBig(sz);
Block *tem = freeList_;
if (tem) {
tem->header.seg->liveCount += 1;
freeList_ = tem->next;
return &(tem->next);
}
else
return alloc1();
}
void *Allocator::allocSimple(size_t sz)
{
BlockHeader *p = (BlockHeader *)::operator new(sz + sizeof(BlockHeader));
p->seg = 0;
return p + 1;
}
void Allocator::free(void *p)
{
BlockHeader *b = ((BlockHeader *)p) - 1;
SegmentHeader *seg = b->seg;
if (seg == 0)
::operator delete(b);
else {
Block **freeList = seg->freeList;
if (freeList == 0) {
seg->liveCount -= 1;
if (seg->liveCount == 0)
::operator delete(seg);
}
else {
((Block *)b)->next = *freeList;
*freeList = (Block *)b;
seg->liveCount -= 1;
}
}
}
void *Allocator::alloc1()
{
SegmentHeader *seg
= (SegmentHeader *)::operator new(sizeof(SegmentHeader)
+ ((objectSize_ + sizeof(BlockHeader))
* blocksPerSegment_));
seg->next = segments_;
segments_ = seg;
seg->liveCount = 1;
seg->freeList = &freeList_;
char *p = (char *)(seg + 1);
Block *head = 0;
for (size_t n = blocksPerSegment_; n > 0; n--) {
((Block *)p)->next = head;
((Block *)p)->header.seg = seg;
head = (Block *)p;
p += sizeof(BlockHeader) + objectSize_;
}
freeList_ = head->next;
return &(head->next);
}
void Allocator::tooBig(size_t sz)
{
ASSERT(sz <= objectSize_);
}
#ifdef SP_NAMESPACE
}
#endif