Show AllocRing.C syntax highlighted
// This may look like C code, but it is really -*- C++ -*-
/*
Copyright (C) 1989 Free Software Foundation
written by Doug Lea (dl@rocky.oswego.edu)
This file is part of the GNU C++ Library. This library is free
software; you can redistribute it and/or modify it under the terms of
the GNU Library General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version. 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 GNU Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef __GNUG__
#pragma implementation
#endif
#include <std.h>
#include <AllocRing.h>
#include <new>
AllocRing::AllocRing(int max)
:n(max), current(0), nodes(new AllocQNode[max])
{
for (int i = 0; i < n; ++i)
{
nodes[i].ptr = 0;
nodes[i].sz = 0;
}
}
int AllocRing::find(void* p)
{
if (p == 0) return -1;
for (int i = 0; i < n; ++i)
if (nodes[i].ptr == p)
return i;
return -1;
}
void AllocRing::clear()
{
for (int i = 0; i < n; ++i)
{
if (nodes[i].ptr != 0)
{
operator delete(nodes[i].ptr);
nodes[i].ptr = 0;
}
nodes[i].sz = 0;
}
current = 0;
}
void AllocRing::free(void* p)
{
int idx = find(p);
if (idx >= 0)
{
operator delete(nodes[idx].ptr);
nodes[idx].ptr = 0;
}
}
AllocRing::~AllocRing()
{
clear();
}
int AllocRing::contains(void* p)
{
return find(p) >= 0;
}
static inline unsigned int good_size(unsigned int s)
{
unsigned int req = s + 4;
unsigned int good = 8;
while (good < req) good <<= 1;
return good - 4;
}
void* AllocRing::alloc(int s)
{
unsigned int size = good_size(s);
void* p;
if (nodes[current].ptr != 0 &&
nodes[current].sz >= int(size) &&
nodes[current].sz < int(4 * size))
p = nodes[current].ptr;
else
{
if (nodes[current].ptr != 0) operator delete (nodes[current].ptr);
p = operator new (size);
nodes[current].ptr = p;
nodes[current].sz = size;
}
++current;
if (current >= n) current = 0;
return p;
}
See more files for this project here