diff -r 000000000000 -r a61af66fc99e src/share/vm/gc_implementation/shared/gSpaceCounters.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/shared/gSpaceCounters.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2002-2004 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// A GSpaceCounter is a holder class for performance counters
+// that track a space;
+
+class GSpaceCounters: public CHeapObj {
+  friend class VMStructs;
+
+ private:
+  PerfVariable*      _capacity;
+  PerfVariable*      _used;
+
+  // Constant PerfData types don't need to retain a reference.
+  // However, it's a good idea to document them here.
+  // PerfConstant*     _size;
+
+  Generation*       _gen;
+  char*             _name_space;
+
+ public:
+
+  GSpaceCounters(const char* name, int ordinal, size_t max_size, Generation* g,
+                 GenerationCounters* gc, bool sampled=true);
+
+  ~GSpaceCounters() {
+    if (_name_space != NULL) FREE_C_HEAP_ARRAY(char, _name_space);
+  }
+
+  inline void update_capacity() {
+    _capacity->set_value(_gen->capacity());
+  }
+
+  inline void update_used() {
+    _used->set_value(_gen->used());
+  }
+
+  // special version of update_used() to allow the used value to be
+  // passed as a parameter. This method can can be used in cases were
+  // the  utilization is already known and/or when the _gen->used()
+  // method is known to be expensive and we want to avoid unnecessary
+  // calls to it.
+  //
+  inline void update_used(size_t used) {
+    _used->set_value(used);
+  }
+
+  inline void inc_used(size_t size) {
+    _used->inc(size);
+  }
+
+  debug_only(
+    // for security reasons, we do not allow arbitrary reads from
+    // the counters as they may live in shared memory.
+    jlong used() {
+      return _used->get_value();
+    }
+    jlong capacity() {
+      return _used->get_value();
+    }
+  )
+
+  inline void update_all() {
+    update_used();
+    update_capacity();
+  }
+
+  const char* name_space() const        { return _name_space; }
+};
+
+class GenerationUsedHelper : public PerfLongSampleHelper {
+  private:
+    Generation* _gen;
+
+  public:
+    GenerationUsedHelper(Generation* g) : _gen(g) { }
+
+    inline jlong take_sample() {
+      return _gen->used();
+    }
+};