src/hotspot/share/gc/g1/g1HeapSizingPolicy.hpp
changeset 47216 71c04702a3d5
parent 37144 b7ae74d4d5d8
child 49806 2d62570a615c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1HeapSizingPolicy.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2016, 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_G1_G1HEAPSIZINGPOLICY_HPP
+#define SHARE_VM_GC_G1_G1HEAPSIZINGPOLICY_HPP
+
+#include "memory/allocation.hpp"
+
+class G1Analytics;
+class G1CollectedHeap;
+
+class G1HeapSizingPolicy: public CHeapObj<mtGC> {
+  // MinOverThresholdForGrowth must be less than the number of recorded
+  // pause times in G1Analytics, representing the minimum number of pause
+  // time ratios that exceed GCTimeRatio before a heap expansion will be triggered.
+  const static uint MinOverThresholdForGrowth = 4;
+
+  const G1CollectedHeap* _g1;
+  const G1Analytics* _analytics;
+
+  const uint _num_prev_pauses_for_heuristics;
+  // Ratio check data for determining if heap growth is necessary.
+  uint _ratio_over_threshold_count;
+  double _ratio_over_threshold_sum;
+  uint _pauses_since_start;
+
+
+protected:
+  G1HeapSizingPolicy(const G1CollectedHeap* g1, const G1Analytics* analytics);
+public:
+
+  // If an expansion would be appropriate, because recent GC overhead had
+  // exceeded the desired limit, return an amount to expand by.
+  virtual size_t expansion_amount();
+
+  // Clear ratio tracking data used by expansion_amount().
+  void clear_ratio_check_data();
+
+  static G1HeapSizingPolicy* create(const G1CollectedHeap* g1, const G1Analytics* analytics);
+};
+
+#endif // SRC_SHARE_VM_GC_G1_G1HEAPSIZINGPOLICY_HPP