--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/Thread/TestThreadDumpClassInitMonitor.java Tue Jan 15 16:40:31 2019 -0500
@@ -0,0 +1,195 @@
+/*
+ * Copyright (c) 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.
+ */
+
+/*
+ * @test
+ * @bug 8213397
+ * @summary Check that the thread dump shows when a thread is blocked
+ * on a class initialization monitor
+ *
+ * @library /test/lib
+ * @run main/othervm TestThreadDumpClassInitMonitor
+ */
+
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.JDKToolFinder;
+
+import java.io.IOException;
+import java.util.List;
+
+public class TestThreadDumpClassInitMonitor {
+ // jstack tends to be closely bound to the VM that we are running
+ // so use getTestJDKTool() instead of getCompileJDKTool() or even
+ // getJDKTool() which can fall back to "compile.jdk".
+ final static String JSTACK = JDKToolFinder.getTestJDKTool("jstack");
+ final static String PID = "" + ProcessHandle.current().pid();
+
+ final static Thread current = Thread.currentThread();
+
+ /*
+ * This is the output we're looking for:
+ *
+ * "TestThread" #22 prio=5 os_prio=0 cpu=1.19ms elapsed=0.80s tid=0x00007f8f9405d800 nid=0x568b in Object.wait() [0x00007f8fd94d0000]
+ * java.lang.Thread.State: RUNNABLE
+ * Thread: 0x00007f8f9405d800 [0x568b] State: _at_safepoint _has_called_back 0 _at_poll_safepoint 0
+ * JavaThread state: _thread_blocked
+ * at TestThreadDumpClassInitMonitor$Target$1.run(TestThreadDumpClassInitMonitor.java:69)
+ * - waiting on the Class initialization monitor for TestThreadDumpClassInitMonitor$Target
+ *
+ */
+ final static String TEST_THREAD = "TestThread";
+ final static String TEST_THREAD_ENTRY = "\"" + TEST_THREAD;
+ final static String IN_OBJECT_WAIT = "in Object.wait()";
+ final static String THREAD_STATE = "java.lang.Thread.State: RUNNABLE";
+ final static String THREAD_INFO = "Thread:"; // the details are not important
+ final static String JAVATHREAD_STATE = "JavaThread state: _thread_blocked";
+ final static String CURRENT_METHOD = "at TestThreadDumpClassInitMonitor$Target$1.run";
+ final static String WAIT_INFO = "- waiting on the Class initialization monitor for TestThreadDumpClassInitMonitor$Target";
+
+ volatile static boolean ready = false;
+
+ static List<String> stackDump; // jstack output as lines
+
+ static class Target {
+
+ static int field;
+
+ // The main thread will initialize this class and so
+ // execute the actual test logic here.
+ static {
+ if (Thread.currentThread() != current) {
+ throw new Error("Initialization logic error");
+ }
+ System.out.println("Initializing Target class in main thread");
+
+ Thread t = new Thread() {
+ public void run() {
+ System.out.println("Test thread about to access Target");
+ ready = true; // tell main thread we're close
+ // This will block until the main thread completes
+ // static initialization of target
+ Target.field = 42;
+ System.out.println("Test thread done");
+ }
+ };
+ t.setName(TEST_THREAD);
+ t.start();
+
+ // We want to run jstack once the test thread is blocked but
+ // there's no programmatic way to detect that. So we check the flag
+ // that will be set just before it should block, then by the time
+ // we can exec jstack it should be ready.
+ try {
+ while (!ready) {
+ Thread.sleep(200);
+ }
+ }
+ catch (InterruptedException ie) {
+ throw new Error("Shouldn't happen");
+ }
+
+ // Now run jstack
+ try {
+ ProcessBuilder pb = new ProcessBuilder(JSTACK, PID);
+ OutputAnalyzer output = new OutputAnalyzer(pb.start());
+ output.shouldHaveExitValue(0);
+ stackDump = output.asLines();
+ }
+ catch (IOException ioe) {
+ throw new Error("Launching jstack failed", ioe);
+ }
+ }
+ }
+
+
+ public static void main(String[] args) throws Throwable {
+ // Implicitly run the main test logic
+ Target.field = 21;
+
+ // Now check the output of jstack
+ try {
+ int foundLines = 0;
+ parseStack: for (String line : stackDump) {
+ switch(foundLines) {
+ case 0: {
+ if (!line.startsWith(TEST_THREAD_ENTRY)) {
+ continue;
+ }
+ foundLines++;
+ if (!line.contains(IN_OBJECT_WAIT)) {
+ throw new Error("Unexpected initial stack line: " + line);
+ }
+ continue;
+ }
+ case 1: {
+ if (!line.trim().equals(THREAD_STATE)) {
+ throw new Error("Unexpected thread state line: " + line);
+ }
+ foundLines++;
+ continue;
+ }
+ case 2: {
+ if (!line.startsWith(THREAD_INFO)) {
+ throw new Error("Unexpected thread info line: " + line);
+ }
+ foundLines++;
+ continue;
+ }
+ case 3: {
+ if (!line.trim().equals(JAVATHREAD_STATE)) {
+ throw new Error("Unexpected JavaThread state line: " + line);
+ }
+ foundLines++;
+ continue;
+ }
+ case 4: {
+ if (!line.trim().startsWith(CURRENT_METHOD)) {
+ throw new Error("Unexpected current method line: " + line);
+ }
+ foundLines++;
+ continue;
+ }
+ case 5: {
+ if (!line.trim().equals(WAIT_INFO)) {
+ throw new Error("Unexpected monitor information line: " + line);
+ }
+ break parseStack;
+ }
+ default: throw new Error("Logic error in case statement");
+ }
+ }
+
+ if (foundLines == 0) {
+ throw new Error("Unexpected stack content - did not find line starting with "
+ + TEST_THREAD_ENTRY);
+ }
+ }
+ catch (Error e) {
+ // Dump the full stack trace on error so we can check the content
+ for (String line : stackDump) {
+ System.out.println(line);
+ }
+ throw e;
+ }
+ }
+}