--- /dev/null	2019-10-08 16:01:21.069130487 +0800
+++ new/test/hotspot/jtreg/gc/g1/TestSoftMaxHeapSize.java	2020-01-03 17:56:51.551856615 +0800
@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 2012, 2019, 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.
+ */
+
+package gc.g1;
+
+/*
+ * @test TestSoftMaxHeapSize
+ * @bug 8236073
+ * @summary G1: Use SoftMaxHeapSize to guide GC heuristics
+ * @requires vm.gc.G1
+ * @library /test/lib
+ * @modules java.base/jdk.internal.misc
+ *          java.management
+ * @build sun.hotspot.WhiteBox
+ * @run driver ClassFileInstaller sun.hotspot.WhiteBox
+ *                                sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:. gc.g1.TestSoftMaxHeapSize
+ */
+
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.process.ProcessTools;
+import jdk.test.lib.JDKToolLauncher;
+import sun.hotspot.WhiteBox;
+
+public class TestSoftMaxHeapSize {
+
+    private static final int heapSize                       = 128; // MB
+    private static final int heapRegionSize                 = 1;   // MB
+
+    public static final WhiteBox WB = WhiteBox.getWhiteBox();
+
+    public static void main(String[] args) throws Exception {
+        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+            "-XX:+UnlockDiagnosticVMOptions",
+            "-XX:+WhiteBoxAPI",
+            "-Xbootclasspath/a:.",
+            "-XX:+UseG1GC",
+            "-Xms" + heapSize + "m",
+            "-Xmx" + heapSize + "m",
+            "-XX:G1HeapRegionSize=" + heapRegionSize + "m",
+            "-Xlog:gc*=debug",
+            "-Dtest.jdk=" + System.getProperty("test.jdk"),
+            SoftMaxHeapSizeShrinkInYoungGC.class.getName());
+
+        OutputAnalyzer output = new OutputAnalyzer(pb.start());
+        System.out.println(output.getOutput());
+        output.shouldContain("Pause Young");
+        output.shouldContain("Shrink the heap in concurrent. shrinking amount: 100663296B");
+        output.shouldMatch("Pause Young.*32M");
+        // Should have explicit full GC within SoftMaxHeapSize
+        output.shouldMatch("Pause Full.*32M");
+        output.shouldHaveExitValue(0);
+
+        pb = ProcessTools.createJavaProcessBuilder(
+            "-XX:+UnlockDiagnosticVMOptions",
+            "-XX:+WhiteBoxAPI",
+            "-Xbootclasspath/a:.",
+            "-XX:+UseG1GC",
+            "-Xms" + heapSize + "m",
+            "-Xmx" + heapSize + "m",
+            "-XX:G1HeapRegionSize=" + heapRegionSize + "m",
+            "-Xlog:gc*",
+            "-Dtest.jdk=" + System.getProperty("test.jdk"),
+            SoftMaxHeapSizeShrinkAfterMixedGC.class.getName());
+
+        output = new OutputAnalyzer(pb.start());
+        System.out.println(output.getOutput());
+        output.shouldContain("Pause Full");
+        output.shouldContain("Pause Young (Mixed)");
+        output.shouldMatch("Pause Young.*32M");
+        output.shouldHaveExitValue(0);
+
+        pb = ProcessTools.createJavaProcessBuilder(
+            "-XX:+UnlockDiagnosticVMOptions",
+            "-XX:+WhiteBoxAPI",
+            "-Xbootclasspath/a:.",
+            "-XX:+UseG1GC",
+            "-Xms" + heapSize + "m",
+            "-Xmx" + heapSize + "m",
+            "-XX:G1HeapRegionSize=" + heapRegionSize + "m",
+            "-Xlog:gc*",
+            "-Dtest.jdk=" + System.getProperty("test.jdk"),
+            SoftMaxHeapSizeExpansion.class.getName());
+
+        output = new OutputAnalyzer(pb.start());
+        System.out.println(output.getOutput());
+        output.shouldMatch("Pause Young.*32M");
+        // Should expand to Xmx in Full GC
+        output.shouldMatch("Pause Full.*128M");
+        output.shouldContain("java.lang.OutOfMemoryError: Java heap space");
+        output.shouldHaveExitValue(1);
+    }
+
+    public static OutputAnalyzer jinfo(String... toolArgs) throws Exception {
+        JDKToolLauncher launcher = JDKToolLauncher.createUsingTestJDK("jinfo");
+        if (toolArgs != null) {
+            for (String toolArg : toolArgs) {
+                launcher.addToolArg(toolArg);
+            }
+        }
+
+        String pid = Long.toString(ProcessTools.getProcessId());
+        launcher.addToolArg(pid);
+
+        ProcessBuilder processBuilder = new ProcessBuilder();
+        processBuilder.command(launcher.getCommand());
+        OutputAnalyzer output = ProcessTools.executeProcess(processBuilder);
+        return output;
+    }
+
+    static class SoftMaxHeapSizeShrinkInYoungGC {
+
+        public static void main(String [] args) throws Exception {
+            Object[] array = new Object[1024];
+            for (int i = 0; i < 1024; i++) {
+                array[i] = new int[1024];
+            }
+            WB.youngGC();
+            OutputAnalyzer output = TestSoftMaxHeapSize.jinfo("-flag",
+                                                              "SoftMaxHeapSize="
+                                                              + 32 * 1024 * 1024);
+            output.shouldHaveExitValue(0);
+            WB.youngGC();
+            WB.fullGC();
+        }
+    }
+
+    static class SoftMaxHeapSizeShrinkAfterMixedGC {
+
+        public static void main(String [] args) throws Exception {
+            // Create 20MB+ objects
+            Object[] array = new Object[1024*1024];
+            for (int i = 0; i < 1024*1024; i++) {
+                array[i] = new byte[10];
+            }
+            WB.youngGC();
+            WB.fullGC();
+            OutputAnalyzer output = TestSoftMaxHeapSize.jinfo("-flag",
+                                                              "SoftMaxHeapSize="
+                                                              + 32 * 1024 * 1024);
+            output.shouldHaveExitValue(0);
+            for (int i = 0; i < 1024*1024; i++) {
+                array[i] = null;
+            }
+            WB.youngGC(); // Cannot trigger shrink
+            // Make sure the mixed GC and shrink happen
+            WB.youngGC();
+            Thread.sleep(1000);
+            WB.youngGC();
+            Thread.sleep(1000);
+            WB.youngGC();
+            Thread.sleep(1000);
+            WB.youngGC();
+            Thread.sleep(1000);
+            WB.youngGC();
+        }
+    }
+
+    static class SoftMaxHeapSizeExpansion {
+
+        public static void main(String [] args) throws Exception {
+            // Create 20MB+ objects
+            Object[] array = new Object[1024*1024];
+            for (int i = 0; i < 1024; i++) {
+                array[i] = new byte[10];
+            }
+            OutputAnalyzer output = TestSoftMaxHeapSize.jinfo("-flag",
+                                                              "SoftMaxHeapSize="
+                                                              + 32 * 1024 * 1024);
+            WB.youngGC();
+            output.shouldHaveExitValue(0);
+            // Allocate to OOM
+            for (int i = 0; i < 1024*1024; i++) {
+                array[i] = new byte[120];
+            }
+        }
+    }
+
+}