The following test program creates 10 threads, each thread then executes
1000 times "/bin/ls". It can run successfully on Solaris but will
hang on Linux with JDK 1.3.1 or 1.4-beta.

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public class ExecTest
{
    public static void main(String[] argv)
    {
        for (int i = 1; i < 10; i++) {
            final int ii = i;
            new Thread() {
                public void run()
                {
                    ExecTest c = new ExecTest(ii);
                }
            }.start();
        }
    }

    ExecTest(int i)
    {
        doExecs(i);
    }

    private void doExecs(int ii)
    {
        int i = 0;
        while (true) {
            try {
                Runtime rt = Runtime.getRuntime();
                Process p = rt.exec("/bin/ls");
                p.waitFor();
                System.err.println("Thread " + ii + " created " +
                                   ++i + " processes so far");
                if (i >= 1000) {
                    System.err.println("Thread " + ii + "finished.");
                    break;
                }
            } catch (Exception e) {
                System.out.println(e.getMessage());
                e.printStackTrace();
                System.exit(1);
            }
        }
    }
}
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