8211123: GC Metaspace printing after full gc

Move GC printing to after usage is calculated

Co-authored-by: Jiapeng Li <nijiaben@perfma.com>
Reviewed-by: tschatzl, stuefe

src/hotspot/share/gc/shared/genCollectedHeap.cpp

@@ -649,9 +649,6 @@ void GenCollectedHeap::do_collection(bool           full,
     // a whole heap collection.
     complete = complete || collected_old;
 
-    print_heap_change(young_prev_used, old_prev_used);
-    MetaspaceUtils::print_metaspace_change(metadata_prev_used);
-
     // Adjust generation sizes.
     if (collected_old) {
       _old_gen->compute_new_size();
@@ -667,6 +664,9 @@ void GenCollectedHeap::do_collection(bool           full,
       update_full_collections_completed();
     }
 
+    print_heap_change(young_prev_used, old_prev_used);
+    MetaspaceUtils::print_metaspace_change(metadata_prev_used);
+
     // Track memory usage and detect low memory after GC finishes
     MemoryService::track_memory_usage();
 

test/hotspot/jtreg/gc/logging/TestMetaSpaceLog.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, Google 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.
+ */
+
+import java.io.File;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.List;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
+import java.util.regex.Matcher;
+
+import jdk.test.lib.Asserts;
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.process.ProcessTools;
+import sun.hotspot.WhiteBox;
+
+/*
+ * @test TestMetaSpaceLog
+ * @bug 8211123
+ * @summary Ensure that the Metaspace is updated in the log
+ * @requires vm.gc=="null"
+ * @key gc
+ * @library /test/lib
+ * @modules java.base/jdk.internal.misc
+ *          java.management
+ *
+ * @compile TestMetaSpaceLog.java
+ * @run driver ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main TestMetaSpaceLog
+ */
+
+public class TestMetaSpaceLog {
+  private static Pattern metaSpaceRegexp;
+
+  static {
+    // Do this once here.
+    metaSpaceRegexp = Pattern.compile(".*Metaspace: ([0-9]+).*->([0-9]+).*");
+  }
+
+  public static void main(String[] args) throws Exception {
+    testMetaSpaceUpdate("UseParallelGC");
+    testMetaSpaceUpdate("UseG1GC");
+    testMetaSpaceUpdate("UseConcMarkSweepGC");
+    testMetaSpaceUpdate("UseSerialGC");
+  }
+
+  private static void verifyContainsMetaSpaceUpdate(OutputAnalyzer output) {
+    Predicate<String> collectedMetaSpace = line -> check(line);
+
+    // At least one metaspace line from GC should show GC being collected.
+    boolean foundCollectedMetaSpace = output.asLines().stream()
+        .filter(s -> s.contains("[gc,metaspace"))
+        .anyMatch(TestMetaSpaceLog::check);
+    Asserts.assertTrue(foundCollectedMetaSpace);
+  }
+
+  private static boolean check(String line) {
+    Matcher m = metaSpaceRegexp.matcher(line);
+    Asserts.assertTrue(m.matches(), "Unexpected line for metaspace logging: " + line);
+    long before = Long.parseLong(m.group(1));
+    long after  = Long.parseLong(m.group(2));
+    return before > after;
+  }
+
+  private static void testMetaSpaceUpdate(String gcFlag) throws Exception {
+    // Propagate test.src for the jar file.
+    String testSrc= "-Dtest.src=" + System.getProperty("test.src", ".");
+
+    System.err.println("Testing with GC Flag: " + gcFlag);
+    ProcessBuilder pb =
+      ProcessTools.createJavaProcessBuilder(
+          "-XX:+" + gcFlag,
+          "-Xlog:gc*",
+          "-Xbootclasspath/a:.",
+          "-XX:+UnlockDiagnosticVMOptions",
+          "-XX:+WhiteBoxAPI",
+          "-Xmx1000M",
+          "-Xms1000M",
+          testSrc, StressMetaSpace.class.getName());
+
+    OutputAnalyzer output = null;
+    try {
+      output = new OutputAnalyzer(pb.start());
+      verifyContainsMetaSpaceUpdate(output);
+    } catch (Exception e) {
+      // For error diagnosis: print and throw.
+      e.printStackTrace();
+      output.reportDiagnosticSummary();
+      throw e;
+    }
+  }
+
+  static class StressMetaSpace {
+    private static URL[] urls = new URL[1];
+
+    static {
+      try {
+        File jarFile = new File(System.getProperty("test.src") + "/testcases.jar");
+        urls[0] = jarFile.toURI().toURL();
+      } catch (Exception e) {
+        e.printStackTrace();
+      }
+    }
+
+    public static void main(String args[]) {
+      WhiteBox wb = WhiteBox.getWhiteBox();
+      for(int i = 0; i < 10000; i++) {
+        loadClass(wb);
+      }
+      wb.fullGC();
+    }
+
+    public static void loadClass(WhiteBox wb) {
+      try {
+        URLClassLoader ucl = new URLClassLoader(urls);
+        Class.forName("case00", false, ucl);
+      } catch (Exception e) {
+        e.printStackTrace();
+      }
+    }
+  }
+}