jdk-24/test/hotspot/jtreg/serviceability/monitoring/ThreadInfo/GetLockOwnerName/GetLockOwnerName.java
2021-05-15 13:14:49 +00:00

416 lines
17 KiB
Java

/*
* Copyright (c) 2001, 2021, 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 8167108 8265153
* @summary The test checks that ThreadInfo.getLockOwnerName() returns a
* non-null string for a blocked thread and then makes repeated calls
* to getThreadInfo() and ThreadInfo.getLockOwnerName() until the thread
* has exited.
* @requires vm.jvmti
* @run main/othervm/native -agentlib:GetLockOwnerName GetLockOwnerName
*/
import java.io.PrintStream;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
//
// main blocker contender releaser
// ================= ================ =================== ================
// launch blocker
// <launch returns> blocker running
// launch contender enter threadLock
// <launch returns> wait for notify contender running
// launch releaser : block on threadLock
// <launch returns> : : releaser running
// wait for : : wait for notify
// contended enter : : :
// <ready to test> : : :
// getThreadInfo : : :
// verify contender : : :
// lock owner name : : :
// is "blocker" : : :
// notify releaser : : :
// loop until thread : : wait finishes
// is NULL : : notify blocker
// get thread info wait finishes : releaser exits
// get lock owner exit threadLock : :
// name blocker exits enter threadLock :
// join releaser : exit threadLock <exit finishes>
// <join returns> : contender exits
// join blocker <exit finishes> :
// <join returns> :
// join contender <exit finishes>
// <join returns>
//
public class GetLockOwnerName {
private static final String AGENT_LIB = "GetLockOwnerName";
private static final int DEF_TIME_MAX = 60; // default max # secs to test
private static final int JOIN_MAX = 30; // max # secs to wait for join
public static final int TS_INIT = 1; // initial testState
public static final int TS_BLOCKER_RUNNING = 2; // blocker is running
public static final int TS_CONTENDER_RUNNING = 3; // contender is running
public static final int TS_RELEASER_RUNNING = 4; // releaser is running
public static final int TS_CONTENDER_BLOCKED = 5; // contender is blocked
public static final int TS_READY_TO_RELEASE = 6; // ready to release the blocker
public static final int TS_DONE_BLOCKING = 7; // done blocking threadLock
public static final int TS_CONTENDER_DONE = 8; // contender has run; done
public static Object barrierLaunch = new Object(); // controls thread launch
public static Object barrierBlocker = new Object(); // controls blocker
public static Object barrierReleaser = new Object(); // controls releaser
public static Object threadLock = new Object(); // testing object
public static long count = 0;
public static boolean printDebug = false;
public volatile static int testState;
private static void log(String msg) { System.out.println(msg); }
native static int wait4ContendedEnter(GetLockOwnerNameWorker thr);
public static void main(String[] args) throws Exception {
try {
System.loadLibrary(AGENT_LIB);
log("Loaded library: " + AGENT_LIB);
} catch (UnsatisfiedLinkError ule) {
log("Failed to load library: " + AGENT_LIB);
log("java.library.path: " + System.getProperty("java.library.path"));
throw ule;
}
int timeMax = 0;
if (args.length == 0) {
timeMax = DEF_TIME_MAX;
} else {
int argIndex = 0;
int argsLeft = args.length;
if (args[0].equals("-p")) {
printDebug = true;
argIndex = 1;
argsLeft--;
}
if (argsLeft == 0) {
timeMax = DEF_TIME_MAX;
} else if (argsLeft == 1) {
try {
timeMax = Integer.parseUnsignedInt(args[argIndex]);
} catch (NumberFormatException nfe) {
System.err.println("'" + args[argIndex] +
"': invalid timeMax value.");
usage();
}
} else {
usage();
}
}
int retCode = run(timeMax, System.out);
if (retCode != 0) {
throw new RuntimeException("Test failed with retCode=" + retCode);
}
}
public static void logDebug(String mesg) {
if (printDebug) {
System.err.println(Thread.currentThread().getName() + ": " + mesg);
}
}
public static void usage() {
System.err.println("Usage: " + AGENT_LIB + " [-p][time_max]");
System.err.println("where:");
System.err.println(" -p print debug info");
System.err.println(" time_max max looping time in seconds");
System.err.println(" (default is " + DEF_TIME_MAX +
" seconds)");
System.exit(1);
}
public static int run(int timeMax, PrintStream out) {
return (new GetLockOwnerName()).doWork(timeMax, out);
}
public static void checkTestState(int exp) {
if (testState != exp) {
System.err.println("Failure at " + count + " loops.");
throw new InternalError("Unexpected test state value: "
+ "expected=" + exp + " actual=" + testState);
}
}
public int doWork(int timeMax, PrintStream out) {
ThreadMXBean mbean = ManagementFactory.getThreadMXBean();
GetLockOwnerNameWorker blocker; // blocker thread
GetLockOwnerNameWorker contender; // contender thread
GetLockOwnerNameWorker releaser; // releaser thread
System.out.println("About to execute for " + timeMax + " seconds.");
long start_time = System.currentTimeMillis();
while (System.currentTimeMillis() < start_time + (timeMax * 1000)) {
count++;
testState = TS_INIT; // starting the test loop
// launch the blocker thread
synchronized (barrierLaunch) {
blocker = new GetLockOwnerNameWorker("blocker");
blocker.start();
while (testState != TS_BLOCKER_RUNNING) {
try {
barrierLaunch.wait(); // wait until it is running
} catch (InterruptedException ex) {
}
}
}
// launch the contender thread
synchronized (barrierLaunch) {
contender = new GetLockOwnerNameWorker("contender");
contender.start();
while (testState != TS_CONTENDER_RUNNING) {
try {
barrierLaunch.wait(); // wait until it is running
} catch (InterruptedException ex) {
}
}
}
// launch the releaser thread
synchronized (barrierLaunch) {
releaser = new GetLockOwnerNameWorker("releaser");
releaser.start();
while (testState != TS_RELEASER_RUNNING) {
try {
barrierLaunch.wait(); // wait until it is running
} catch (InterruptedException ex) {
}
}
}
// wait for the contender thread to block
logDebug("before contended enter wait");
int retCode = wait4ContendedEnter(contender);
if (retCode != 0) {
throw new RuntimeException("error in JVMTI GetThreadState " +
"or GetCurrentContendedMonitor " +
"retCode=" + retCode);
}
testState = TS_CONTENDER_BLOCKED;
logDebug("done contended enter wait");
//
// At this point, all of the child threads are running
// and we can get to meat of the test:
//
// - query the contender thread and verify that it is blocked
// by the blocker thread
// - tell the releaser thread to release the blocker thread
// - continue to query the contender thread until it exits
//
long id = 0;
ThreadInfo info = null;
int lateCount = 0;
checkTestState(TS_CONTENDER_BLOCKED);
id = contender.getId();
info = mbean.getThreadInfo(id, 0);
String name = info.getLockOwnerName();
if (name == null) {
out.println("Failure at " + count + " loops.");
throw new RuntimeException("ThreadInfo.GetLockOwnerName() "
+ "returned null name for "
+ "contender.");
} else if (!name.equals("blocker")) {
out.println("Failure at " + count + " loops.");
throw new RuntimeException("name='" + name + "': name "
+ "should be blocker.");
} else {
logDebug("ThreadInfo.GetLockOwnerName() returned blocker.");
}
synchronized (barrierReleaser) {
// tell releaser thread to release the blocker thread
testState = TS_READY_TO_RELEASE;
barrierReleaser.notify();
}
while (true) {
// maxDepth == 0 requires no safepoint so alternate.
int maxDepth = ((count % 1) == 1) ? Integer.MAX_VALUE : 0;
info = mbean.getThreadInfo(id, maxDepth);
if (info == null) {
// the contender has exited
break;
}
name = info.getLockOwnerName();
// We can't verify that name == null here because contender
// might be slow leaving the threadLock monitor.
lateCount++;
}
logDebug("made " + lateCount + " late calls to getThreadInfo() " +
"and info.getLockOwnerName().");
try {
releaser.join(JOIN_MAX * 1000);
if (releaser.isAlive()) {
System.err.println("Failure at " + count + " loops.");
throw new InternalError("releaser thread is stuck");
}
blocker.join(JOIN_MAX * 1000);
if (blocker.isAlive()) {
System.err.println("Failure at " + count + " loops.");
throw new InternalError("blocker thread is stuck");
}
contender.join(JOIN_MAX * 1000);
if (contender.isAlive()) {
System.err.println("Failure at " + count + " loops.");
throw new InternalError("contender thread is stuck");
}
} catch (InterruptedException ex) {
}
checkTestState(TS_CONTENDER_DONE);
}
System.out.println("Executed " + count + " loops in " + timeMax +
" seconds.");
return 0;
}
}
class GetLockOwnerNameWorker extends Thread {
public GetLockOwnerNameWorker(String name) {
super(name);
}
public void run() {
GetLockOwnerName.logDebug("thread running");
//
// The blocker thread:
// - grabs threadLock
// - holds threadLock until we tell it let go
// - releases threadLock
//
if (getName().equals("blocker")) {
// grab threadLock before we tell main we are running
GetLockOwnerName.logDebug("before enter threadLock");
synchronized(GetLockOwnerName.threadLock) {
GetLockOwnerName.logDebug("enter threadLock");
GetLockOwnerName.checkTestState(GetLockOwnerName.TS_INIT);
synchronized(GetLockOwnerName.barrierBlocker) {
synchronized(GetLockOwnerName.barrierLaunch) {
// tell main we are running
GetLockOwnerName.testState = GetLockOwnerName.TS_BLOCKER_RUNNING;
GetLockOwnerName.barrierLaunch.notify();
}
GetLockOwnerName.logDebug("thread waiting");
while (GetLockOwnerName.testState != GetLockOwnerName.TS_DONE_BLOCKING) {
try {
// wait for main to tell us when to exit threadLock
GetLockOwnerName.barrierBlocker.wait();
} catch (InterruptedException ex) {
}
}
}
GetLockOwnerName.logDebug("exit threadLock");
}
}
//
// The contender thread:
// - tries to grab the threadLock
// - grabs threadLock
// - releases threadLock
//
else if (getName().equals("contender")) {
synchronized(GetLockOwnerName.barrierLaunch) {
// tell main we are running
GetLockOwnerName.testState = GetLockOwnerName.TS_CONTENDER_RUNNING;
GetLockOwnerName.barrierLaunch.notify();
}
GetLockOwnerName.logDebug("before enter threadLock");
synchronized(GetLockOwnerName.threadLock) {
GetLockOwnerName.logDebug("enter threadLock");
GetLockOwnerName.checkTestState(GetLockOwnerName.TS_DONE_BLOCKING);
GetLockOwnerName.testState = GetLockOwnerName.TS_CONTENDER_DONE;
GetLockOwnerName.logDebug("exit threadLock");
}
}
//
// The releaser thread:
// - tries to grab the barrierBlocker (should not block!)
// - grabs barrierBlocker
// - releases the blocker thread
// - releases barrierBlocker
//
else if (getName().equals("releaser")) {
synchronized(GetLockOwnerName.barrierReleaser) {
synchronized(GetLockOwnerName.barrierLaunch) {
// tell main we are running
GetLockOwnerName.testState = GetLockOwnerName.TS_RELEASER_RUNNING;
GetLockOwnerName.barrierLaunch.notify();
}
GetLockOwnerName.logDebug("thread waiting");
while (GetLockOwnerName.testState != GetLockOwnerName.TS_READY_TO_RELEASE) {
try {
// wait for main to tell us when to continue
GetLockOwnerName.barrierReleaser.wait();
} catch (InterruptedException ex) {
}
}
}
GetLockOwnerName.logDebug("before enter barrierBlocker");
synchronized (GetLockOwnerName.barrierBlocker) {
GetLockOwnerName.logDebug("enter barrierBlocker");
// tell blocker thread to exit threadLock
GetLockOwnerName.testState = GetLockOwnerName.TS_DONE_BLOCKING;
GetLockOwnerName.barrierBlocker.notify();
GetLockOwnerName.logDebug("released blocker thread");
GetLockOwnerName.logDebug("exit barrierBlocker");
}
}
}
}