8035406: Improve data structure for Code Cache remembered sets

Change the code cache remembered sets data structure from a GrowableArray to a chunked list of nmethods. This makes the data structure more amenable to parallelization, and decreases freeing time.

Reviewed-by: mgerdin, brutisso

hotspot/test/gc/g1/TestGCLogMessages.java

@@ -0,0 +1,61 @@
+/*
+ * 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.
+ */
+
+/*
+ * @test TestPrintGCDetails
+ * @bug 8035406
+ * @summary Ensure that the PrintGCDetails output for a minor GC with G1
+ * includes the expected necessary messages.
+ * @key gc
+ * @library /testlibrary
+ */
+
+import com.oracle.java.testlibrary.ProcessTools;
+import com.oracle.java.testlibrary.OutputAnalyzer;
+
+public class TestGCLogMessages {
+  public static void main(String[] args) throws Exception {
+
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-XX:+UseG1GC",
+                                                              "-Xmx10M",
+                                                              "-XX:+PrintGCDetails",
+                                                              GCTest.class.getName());
+
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+    output.shouldContain("[Code Root Purge");
+    output.shouldHaveExitValue(0);
+  }
+
+  static class GCTest {
+    private static byte[] garbage;
+    public static void main(String [] args) {
+      System.out.println("Creating garbage");
+      // create 128MB of garbage. This should result in at least one GC
+      for (int i = 0; i < 1024; i++) {
+        garbage = new byte[128 * 1024];
+      }
+      System.out.println("Done");
+    }
+  }
+}