386BSD 0.1 development

Work on file usr/src/lib/libg++/libg++/AllocRing.cc

Co-Authored-By: Lynne Greer Jolitz <ljolitz@cardio.ucsf.edu>
Synthesized-from: 386BSD-0.1

diff --git a/usr/src/lib/libg++/libg++/AllocRing.cc b/usr/src/lib/libg++/libg++/AllocRing.cc
new file mode 100644 (file)
index 0000000..ea57d9f
--- /dev/null
+++ b/usr/src/lib/libg++/libg++/AllocRing.cc
@@ -0,0 +1,121 @@
+// 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 GNU CC.
+
+GNU CC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY.  No author or distributor
+accepts responsibility to anyone for the consequences of using it
+or for whether it serves any particular purpose or works at all,
+unless he says so in writing.  Refer to the GNU CC General Public
+License for full details.
+
+Everyone is granted permission to copy, modify and redistribute
+GNU CC, but only under the conditions described in the
+GNU CC General Public License.   A copy of this license is
+supposed to have been given to you along with GNU CC so you
+can know your rights and responsibilities.  It should be in a
+file named COPYING.  Among other things, the copyright notice
+and this notice must be preserved on all copies.  
+*/
+
+#ifdef __GNUG__
+#pragma implementation
+#endif
+#include <std.h>
+#include <AllocRing.h>
+#include <new.h>
+
+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)
+    {
+      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)
+  {
+    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 >= size && 
+      nodes[current].sz < (4 * size))
+    p = nodes[current].ptr;
+  else
+  {
+    if (nodes[current].ptr != 0) delete nodes[current].ptr;
+    p = new char[size];
+    nodes[current].ptr = p;
+    nodes[current].sz = size;
+  }
+  ++current;
+  if (current >= n) current = 0;
+  return p;
+}
+
+
+    
+#ifdef VMS
+#include "libgxx-fmtq.cc"    // see Obstack.cc for reason for this
+#endif