[Sablevm-developer] Fixed(?) problem with exec()

[Grzegorz B. P. <ga...@de...>]

Hi all,

I need a confirmation, as I haven't touched this stuff yet and
I might be just missing something.

exec() is broken in current staging and 1.1.0. If you tried to run
such a simple program:

public class ExecTest {
  public static void main(String []args) {
    try {
      Process child = Runtime.getRuntime().exec("/bin/sleep 1");
      child.waitFor();
    }
    catch(Exception e) {
      System.out.println("Execution exception catched");
    }
    System.out.println("Execution finished");
  }
}

$ sablevm -Y ExecTest
Java_java_lang_ProcessImpl_nativeWaitFor: No child processes
Child did not exit normally.

strace showed that waitpid() is called twice, second time after
the child exited. So I scratched my head and after 3 minutes in
src/libsablevm/java_lang_ProcessImpl.c in ..._nativeWaitFor
i saw more less such thing:

waitpid(pid, &status, 0);

if (nonblocking) {
  waitpid(pid, &status, WNOHANG);
} else {
  waitpid(pid, &status, 0);
}

Existence of the first waitpid makes no sense to me. I commented
it out in just-uploaded sablevm Debian packages as it seemed to
solve the problem.

Am I missing anything or should it get to staging too?

It's quite "grave" thing, I'd say. If it wasn't me who'd have to
make the next release, I'd push for 1.1.1 ASAP :-/

Cheers,

				Grzegorz B. Prokopski

-- 
Grzegorz B. Prokopski <ga...@de...>
Debian GNU/Linux      http://www.debian.org
SableVM - LGPLed JVM  http://www.sablevm.org
Why SableVM ?!?       http://devel.sablevm.org/wiki/WhySableVM