TEST_BUG: Race conditions in PingPong.java

Name: vsR10238 Date: 09/03/2003


Filed By : J2SE-SQA [###@###.###
JDK : JDK1.5.0
Testbase : Regression-cte
Platform[s] : Solaris 10 (x86) (CDE)
Falling test[s]:
         CTE_REGTEST/Generic/4514097/PingPong.java

Regression-CTE test CTE_REGTEST/Generic/4514097/PingPong.java from the test suite for JDK1.5.0
fails with JDK1.5.0, JDK1.4.2 due to races in the test.

Below is an excerpt from the PingPong.main method (PingPong.java):

             PingPong[] rest = new PingPong[count];
             for (int i = 0; i < count; i++)
             {
                 rest[i] = new PingPong("" + i, 0);
             }

             System.out.println(" Main sleeping for 1 second..");

             try {
                               sleep(1000);
             }
             catch (InterruptedException e)
             {
             }
             for (int i = 0; i < count; i++)
             {
                 rest[i].start();
             }
              PingPong one = new PingPong("FirstOne", 0); // Code modified so that it can notify all waiting threads..
             one.start();

There is no delay between starting the waiting threads and the notifying one.
It seems like sleep(1000) was placed a little bit higher than was intended. It should be placed
after the loop with rest[i].start.

As a result the PingPong thread named "one" notified the "rest" threads before they had even started,
which caused the failure and the following output in test.out from the test and the JVM profiler:

------------------------------------------------------------------
  Main sleeping for 1 second..
Sleeping for 1 Second ....

Notifying all ....

FirstOne
It is not "FirstOne" ... Hence waiting on Integer ...

It is not "FirstOne" ... Hence waiting on Integer ...

It is not "FirstOne" ... Hence waiting on Integer ...

Event ID : 80fbdb8: THREAD_START: Thread Name: Finalizer
Event ID : 80fb3a8: THREAD_START: Thread Name: Reference Handler
Event ID : 806b0a8: THREAD_START: Thread Name: main
Event ID : 81044b0: THREAD_START: Thread Name: Signal Dispatcher
Event ID : 811d120: THREAD_START: Thread Name: Thread-3
Event ID : 811c6e0: THREAD_START: Thread Name: Thread-2
Event ID : 811bca0: THREAD_START: Thread Name: Thread-1
Event ID : 811bb08: THREAD_START: Thread Name: Thread-0
Event ID : 811bb08: MONITOR_WAIT: Object : d041dd30, Timeout : 0
Event ID : 811bca0: MONITOR_WAIT: Object : d041dd30, Timeout : 0
Event ID : 811c6e0: MONITOR_WAIT: Object : d041dd30, Timeout : 0

------------------------------------------------------------------

After I modified the code as follows the test passed.

             for (int i = 0; i < count; i++)
             {
                 rest[i].start();
             }

             System.out.println(" Main sleeping for 1 second..");

             try {
                               sleep(1000);
             }
             catch (InterruptedException e)
             {
             }


              PingPong one = new PingPong("FirstOne", 0); // Code modified so that it can notify all waiting threads..
             one.start();


It is not so easy to reproduce the failure.
For example, the test stable fails only on our Solaris 10 (x86) computer
when I run it using JavaTest on its display.
But the test always passes when I run it via rsh on the same computer.


Test source location:
=====================
/net/jdk/export/jpse04/Regression/1.5.0/test/CTE_REGTEST/Generic/4514097/PingPong.java

jtr file location:
==================
/net/jtgb4u4c.sfbay/export/sail15/results.2/tiger/b17/regtest/x86/sol10_x86_gnome_linux-18/workDir/cte/CTE_REGTEST/Generic/4514097/PingPong.jtr

How to reproduce:
=================
Run the following script (you may need to change its variables)

--- script start ---
#!/bin/sh
RESULT_DIR=`pwd`
WORK_DIR=$RESULT_DIR/workDir/test
REPORT_DIR=$RESULT_DIR/reportDir
JT_HOME="/net/linux-15/export/home/java/jct"
JAVA_HOME="/net/linux-15/export/home/java/jdk1.5.0/x86"
TEST_BASE_PATH="/net/linux-15/export/home/java/regtest.tiger/cte"
TESTVMOPTS="-client"
CLASSPATH="$JT_HOME/classes:$JT_HOME/lib/javatest.jar:$JT_HOME/lib/jtreg.jar"

TEST="CTE_REGTEST/Generic/4514097/PingPong.java"

mkdir -p $WORK_DIR/scratch 2>&1
mkdir -p $WORK_DIR/jtData 2>&1
mkdir -p $REPORT_DIR 2>&1

#rm $WORK_DIR/jtData/ResultCache.jtw 2>&1

cd $WORK_DIR/scratch

$JAVA_HOME/bin/java -server -cp $CLASSPATH -DenvVars=TESTJAVAHOME=$JAVA_HOME,TESTVMOPTS=$TESTVMOPTS,DISPLAY=:0,HOME=$HOME/.regtest,PATH=/bin:/usr/bin,CPAPPEND=$JT_HOME/jemmy/jemmy.jar,TZ=,LC_ALL=en_US,LC_CTYPE=en_US,LANG=en_US,LPDEST= -DDISPLAY=:0 -DlocalHost="linux-18" -Dprogram=jtreg com.sun.javatest.regtest.Main -a -v default -batch -params -w "$WORK_DIR" -r "$REPORT_DIR" -t "$TEST_BASE_PATH" "$TEST_BASE_PATH/$TEST"

--- script end ---

Script output:
==============

Test output (jtr part):
=======================
----------System.out:(5/129)----------
  inflated: i386-libdev1.so
  inflated: Linux-libdev1.so
  inflated: sparc-libdev1.so
  inflated: dev1.dll
Invalid output, check it.
----------System.err:(1/35)----------
java full version "1.5.0-beta-b17"
result: Failed. Execution failed: exit code 1


test result: Failed. Execution failed: exit code 1


Specific machine info:
======================
Hostname: linux-18
OS: Solaris 10 (x86) (CDE)



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