hotspot/src/share/vm/gc_implementation/g1/heapRegionBounds.hpp
changeset 26840 f3c7613a7bbb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionBounds.hpp	Tue Sep 09 04:48:41 2014 +0200
@@ -0,0 +1,52 @@
+/*
+ * 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_GC_IMPLEMENTATION_G1_HEAPREGIONBOUNDS_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONBOUNDS_HPP
+
+class HeapRegionBounds : public AllStatic {
+private:
+  // Minimum region size; we won't go lower than that.
+  // We might want to decrease this in the future, to deal with small
+  // heaps a bit more efficiently.
+  static const size_t MIN_REGION_SIZE = 1024 * 1024;
+
+  // Maximum region size; we don't go higher than that. There's a good
+  // reason for having an upper bound. We don't want regions to get too
+  // large, otherwise cleanup's effectiveness would decrease as there
+  // will be fewer opportunities to find totally empty regions after
+  // marking.
+  static const size_t MAX_REGION_SIZE = 32 * 1024 * 1024;
+
+  // The automatic region size calculation will try to have around this
+  // many regions in the heap (based on the min heap size).
+  static const size_t TARGET_REGION_NUMBER = 2048;
+
+public:
+  static inline size_t min_size();
+  static inline size_t max_size();
+  static inline size_t target_number();
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONBOUNDS_HPP