8056240: Investigate increased GC remark time after class unloading changes in CRM Fuse

Reviewed-by: mgerdin, coleenp, bdelsart

hotspot/src/share/vm/utilities/chunkedList.hpp

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_UTILITIES_CHUNKED_LIST_HPP
+#define SHARE_VM_UTILITIES_CHUNKED_LIST_HPP
+
+#include "memory/allocation.hpp"
+#include "utilities/debug.hpp"
+
+template <class T, MEMFLAGS F> class ChunkedList : public CHeapObj<F> {
+  template <class U> friend class TestChunkedList;
+
+  static const size_t BufferSize = 64;
+
+  T  _values[BufferSize];
+  T* _top;
+
+  ChunkedList<T, F>* _next_used;
+  ChunkedList<T, F>* _next_free;
+
+  T const * end() const {
+    return &_values[BufferSize];
+  }
+
+ public:
+  ChunkedList<T, F>() : _top(_values), _next_used(NULL), _next_free(NULL) {}
+
+  bool is_full() const {
+    return _top == end();
+  }
+
+  void clear() {
+    _top = _values;
+    // Don't clear the next pointers since that would interfere
+    // with other threads trying to iterate through the lists.
+  }
+
+  void push(T m) {
+    assert(!is_full(), "Buffer is full");
+    *_top = m;
+    _top++;
+  }
+
+  void set_next_used(ChunkedList<T, F>* buffer) { _next_used = buffer; }
+  void set_next_free(ChunkedList<T, F>* buffer) { _next_free = buffer; }
+
+  ChunkedList<T, F>* next_used() const          { return _next_used; }
+  ChunkedList<T, F>* next_free() const          { return _next_free; }
+
+  size_t size() const {
+    return pointer_delta(_top, _values, sizeof(T));
+  }
+
+  T at(size_t i) {
+    assert(i < size(), err_msg("IOOBE i: " SIZE_FORMAT " size(): " SIZE_FORMAT, i, size()));
+    return _values[i];
+  }
+};
+
+#endif // SHARE_VM_UTILITIES_CHUNKED_LIST_HPP