Re: 1.3, kernel 2.6, signals

nicole <[email protected]> Wed, 17 Mar 2004 19:33:46 -0800 (PST)

Newsgroups	gmane.comp.java.linux.general
Message-ID	<[email protected]>

Ah, the IBM JDK was holding the signals for the JVM, that explains why
that didn't work (had to use -Xrs).

Works with 2.6:
IBM 1.3.1-6 (with -Xrs)
Sun 1.4.2_03 (no -Xrs)

Does Not Work with 2.6:
Blackdown 1.3.1
Sun 1.3.1_10
Sun 1.3.1_11

Untested:
Blackdown 1.4.x
IBM 1.4.x

Everything tested works fine on a 2.4 kernel.

Attached is the test code that I am using to test the signals.

Feedback welcome... otherwise I am most likely going to test and switch to
the IBM 1.3.1-6 JRE.

Thanks!
-nicole

At 16:52 on Mar 17, nicole shook the earth with:

> The IBM JRE did not appear to catch the signals at all, they get passed
> right through and kill the application.
>
> Once I have something that tests the signals exclusively, hopefully I can
> test all three of the JVMs and see what happens.
>
> At 12:13 on Mar 16, Tony Reix shook the earth with:
>
> > Hi Nicole,
> >
> > { ...
> > { I will be constructing a basic application that just does the signal
> > { handling similar to my application so I can use it to test.
> >
> > Seems your problem is not easy to understand ...
> > Let us know when you have built such a basic application. At that
> > time we'll try to reproduce it there, probably with the Sun or IBM JVMs.
> > Did you try with IBM JVM ?
> >
> > Thanks for helping stabilizing NPTL.

SignalTest.java (text/x-java, 2.3 KB)

package test;
import sun.misc.Signal;
import sun.misc.SignalHandler;
import java.io.*;

public class SignalTest implements SignalHandler
{
  public SignalTest()
  {
  }
  public static void main(String[] args)
  {
    SignalTest st = new SignalTest();
    st.run();
  }

  public void run()
  {
    System.out.println("Initializing Signals...");
    initSignals();
    System.out.println("Signals Initialized.");
    System.out.println("I'm going to sit here now while you try to kill me"
      + " (type exit to force quit)");

    BufferedReader _input = new BufferedReader(new InputStreamReader(System.in));
    String s = "foo";

    while(!(s.equals("exit")))
    {
      try
      {
          s = _input.readLine();
          s = s.trim();
      }
      catch(java.io.IOException e)
      {
           System.out.println("oops, I didn't expect that: " + e.toString());
      }
    }

    System.out.println("Exiting on user request.");
    System.exit(0);
  }

  protected void initSignals()
  {
    try
    {
      System.out.println("Initializing sig INT");
      Signal.handle(new Signal("INT"), this);
    }
    catch(IllegalArgumentException e)
    {
      // failed
      System.out.println("Signals Caught:" + e.toString());
    }

    try
    {
      System.out.println("Initializing sig HUP");
      Signal.handle(new Signal("HUP"), this);
    }
    catch(IllegalArgumentException e)
    {
      // failed
      System.out.println("Signals Caught:" + e.toString());
    }
    try
    {
      System.out.println("Initializing sig TERM");
      Signal.handle(new Signal("TERM"), this);
    }
    catch(IllegalArgumentException e)
    {
      // failed
      System.out.println("Signals Caught: " + e.toString());
    }

    try
    {
      System.out.println("Initializing sig USR1");
      Signal.handle(new Signal("USR1"), this);
    }
    catch(IllegalArgumentException e)
    {
      // failed
      System.out.println("Signals Caught: " + e.toString());
    }
  }

  public void handle(Signal sig)
  {
    System.out.println("Caught " + sig.toString() + " ("+sig.getNumber()+")");
    if(sig.toString().equals("SIGTERM"))
    {
      System.out.println("Caught sig TERM, exiting");
      System.exit(-1);
    }
  }
}