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Posted to issues@commons.apache.org by "Dmitri Blinov (JIRA)" <ji...@apache.org> on 2016/07/12 13:32:20 UTC
[jira] [Updated] (JEXL-206) testCallableCancel() test hangs
sporadically
[ https://issues.apache.org/jira/browse/JEXL-206?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Dmitri Blinov updated JEXL-206:
-------------------------------
Description:
I'm struggling with strange behaviour of the building process, it seems that time after time the process hangs somewhere in the middle of the tests stage. First I thought it was somehow related to memory problems so I changed fork mode of the test plugin by adding <forkMode>pertest</forkMode> to maven-surefire-plugin configuration. But that helped for a couple of times to cleanly build jexl and run all tests successfully. The other times it simply hanged on test stage. I have managed to detect that it is the testCallableCancel() test that hangs. One of its worker threads has a stack trace as follows:
{code}
org.apache.commons.jexl3.internal.Interpreter.visit(Interpreter.java:893)
org.apache.commons.jexl3.parser.ASTWhileStatement.jjtAccept(ASTWhileStatement.java:18)
org.apache.commons.jexl3.internal.Interpreter.visit(Interpreter.java:1119)
org.apache.commons.jexl3.parser.ASTJexlScript.jjtAccept(ASTJexlScript.java:55)
org.apache.commons.jexl3.internal.Interpreter.interpret(Interpreter.java:210)
org.apache.commons.jexl3.internal.Script$Callable.interpret(Script.java:364)
org.apache.commons.jexl3.internal.Script$Callable.call(Script.java:372)
- locked org.apache.commons.jexl3.internal.Script$Callable@18399f62
java.util.concurrent.FutureTask.run(FutureTask.java:262)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
java.lang.Thread.run(Thread.java:745)
{code}
I have adjusted the test code with prinln() to dig further what is going on:
{code}
@Test
public void testCallableCancel() throws Exception {
System.out.println("testCallableCancel(): started");
JexlScript e = JEXL.createScript("while(true);");
final Script.Callable c = (Script.Callable) e.callable(null);
Object t = 42;
Callable<Object> kc = new Callable<Object>() {
@Override
public Object call() throws Exception {
System.out.println("testCallableCancel(): cancel() is called");
return c.cancel();
}
};
Callable<Object> xkc = new Callable<Object>() {
@Override
public Object call() throws Exception {
System.out.println("testCallableCancel(): run() is called");
return c.call();
}
};
ExecutorService executor = Executors.newFixedThreadPool(2);
Future<?> future = executor.submit(xkc);
Future<?> kfc = executor.submit(kc);
try {
Assert.assertTrue((Boolean) kfc.get());
System.out.println("testCallableCancel(): canceled()");
t = future.get();
Assert.fail("should have been cancelled");
} catch (ExecutionException xexec) {
// ok, ignore
Assert.assertTrue(xexec.getCause() instanceof JexlException.Cancel);
} finally {
executor.shutdown();
}
Assert.assertTrue(c.isCancelled());
System.out.println("testCallableCancel(): finished");
}
{code}
If the test hangs it prints the following:
{panel}
testCallableCancel(): started
testCallableCancel(): run() is called
testCallableCancel(): cancel() is called
testCallableCancel(): canceled()
{panel}
If the test runs as normal and does not hang it prints the following:
{panel}
testCallableCancel(): started
testCallableCancel(): run() is called
testCallableCancel(): cancel() is called
testCallableCancel(): canceled()
testCallableCancel(): finished
{panel}
was:
I'm struggling with strange behaviour of the building process, it seems that time after time the process hangs somewhere in the middle of the tests stage. First I thought it was somehow related to memory problems so I changed fork mode of the test plugin by adding <forkMode>pertest</forkMode> to maven-surefire-plugin configuration. But that helped for a couple of times to cleanly build jexl and run all tests successfully. The other times it simply hanged on test stage. I have managed to detect that it is the testCancelLoopWait() test that hangs. It writes to the console the message
{panel}
WARNING: org.apache.commons.jexl3.ScriptCallableTest.testCancelLoopWait@1:20 execution cancelled
{panel}
and hangs with its stack trace as follows:
{code}
org.apache.commons.jexl3.internal.Interpreter.visit(Interpreter.java:893)
org.apache.commons.jexl3.parser.ASTWhileStatement.jjtAccept(ASTWhileStatement.java:18)
org.apache.commons.jexl3.internal.Interpreter.visit(Interpreter.java:1119)
org.apache.commons.jexl3.parser.ASTJexlScript.jjtAccept(ASTJexlScript.java:55)
org.apache.commons.jexl3.internal.Interpreter.interpret(Interpreter.java:210)
org.apache.commons.jexl3.internal.Script$Callable.interpret(Script.java:364)
org.apache.commons.jexl3.internal.Script$Callable.call(Script.java:372)
- locked org.apache.commons.jexl3.internal.Script$Callable@18399f62
java.util.concurrent.FutureTask.run(FutureTask.java:262)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
java.lang.Thread.run(Thread.java:745)
{code}
The problem started manifesting itself right after I had added ScriptInterruptableTest.java (see JEXL-204) but as I understand this test script is completely unrelated to ScriptCallableTest.java so I think it's merely a conicidence. I could not write anything in ScriptInterruptableTest and screw up ScriptCallableTest, right?
PS. I have managed to catch this exactly behavior after removing ScriptInterruptableTest.java completely and making clean build, so I'm 100% sure there is something wrong with the original code, may be race condition or something.
If the test runs as normal and does not hang it prints the following:
{panel}
WARNING: org.apache.commons.jexl3.ScriptCallableTest.testCancelLoopWait@1:20 execution cancelled
...12, 2016 3:31:50 PM org.apache.commons.jexl3.JexlEngine invocationFailed
{panel}
Summary: testCallableCancel() test hangs sporadically (was: testCancelLoopWait() test hangs sporadically?)
Sorry for previous misinformation about testCancelLoopWait(), it turned out that was not testCancelLoopWait() that hanged but the one that was run after it.
> testCallableCancel() test hangs sporadically
> --------------------------------------------
>
> Key: JEXL-206
> URL: https://issues.apache.org/jira/browse/JEXL-206
> Project: Commons JEXL
> Issue Type: Bug
> Affects Versions: 3.0
> Reporter: Dmitri Blinov
>
> I'm struggling with strange behaviour of the building process, it seems that time after time the process hangs somewhere in the middle of the tests stage. First I thought it was somehow related to memory problems so I changed fork mode of the test plugin by adding <forkMode>pertest</forkMode> to maven-surefire-plugin configuration. But that helped for a couple of times to cleanly build jexl and run all tests successfully. The other times it simply hanged on test stage. I have managed to detect that it is the testCallableCancel() test that hangs. One of its worker threads has a stack trace as follows:
> {code}
> org.apache.commons.jexl3.internal.Interpreter.visit(Interpreter.java:893)
> org.apache.commons.jexl3.parser.ASTWhileStatement.jjtAccept(ASTWhileStatement.java:18)
> org.apache.commons.jexl3.internal.Interpreter.visit(Interpreter.java:1119)
> org.apache.commons.jexl3.parser.ASTJexlScript.jjtAccept(ASTJexlScript.java:55)
> org.apache.commons.jexl3.internal.Interpreter.interpret(Interpreter.java:210)
> org.apache.commons.jexl3.internal.Script$Callable.interpret(Script.java:364)
> org.apache.commons.jexl3.internal.Script$Callable.call(Script.java:372)
> - locked org.apache.commons.jexl3.internal.Script$Callable@18399f62
> java.util.concurrent.FutureTask.run(FutureTask.java:262)
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> java.lang.Thread.run(Thread.java:745)
> {code}
> I have adjusted the test code with prinln() to dig further what is going on:
> {code}
> @Test
> public void testCallableCancel() throws Exception {
> System.out.println("testCallableCancel(): started");
> JexlScript e = JEXL.createScript("while(true);");
> final Script.Callable c = (Script.Callable) e.callable(null);
> Object t = 42;
> Callable<Object> kc = new Callable<Object>() {
> @Override
> public Object call() throws Exception {
> System.out.println("testCallableCancel(): cancel() is called");
> return c.cancel();
> }
> };
> Callable<Object> xkc = new Callable<Object>() {
> @Override
> public Object call() throws Exception {
> System.out.println("testCallableCancel(): run() is called");
> return c.call();
> }
> };
> ExecutorService executor = Executors.newFixedThreadPool(2);
> Future<?> future = executor.submit(xkc);
> Future<?> kfc = executor.submit(kc);
> try {
> Assert.assertTrue((Boolean) kfc.get());
> System.out.println("testCallableCancel(): canceled()");
> t = future.get();
> Assert.fail("should have been cancelled");
> } catch (ExecutionException xexec) {
> // ok, ignore
> Assert.assertTrue(xexec.getCause() instanceof JexlException.Cancel);
> } finally {
> executor.shutdown();
> }
> Assert.assertTrue(c.isCancelled());
> System.out.println("testCallableCancel(): finished");
> }
> {code}
> If the test hangs it prints the following:
> {panel}
> testCallableCancel(): started
> testCallableCancel(): run() is called
> testCallableCancel(): cancel() is called
> testCallableCancel(): canceled()
> {panel}
> If the test runs as normal and does not hang it prints the following:
> {panel}
> testCallableCancel(): started
> testCallableCancel(): run() is called
> testCallableCancel(): cancel() is called
> testCallableCancel(): canceled()
> testCallableCancel(): finished
> {panel}
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