Re: [cp-patches] RFC: VMThread.sleep mauve fix

[Christian Thalinger]

On Tue, 2005-11-01 at 18:31 +0100, Mark Wielaard wrote:
> The round up probably comes from join() which uses a similar way to
> wait. And according to the bug pointed to in the comment apparently some
> VMs mishandle a zero ms argument (we also had that bug in the past).

It seems that sun also does some rounding in join.  With ns >= 500000
you get an:

java.lang.IllegalArgumentException: timeout value is negative

Maybe we should also behave like this and write some mauve tests for?

> Should we add a ns = 0 after wait() returns here? Whether or not you
> think that change is necessary, please feel free to commit this.

Yes, i already thought about that.  I'll commit the patch like this:

Index: vm/reference/java/lang/VMThread.java
===================================================================
RCS file: /cvsroot/classpath/classpath/vm/reference/java/lang/VMThread.java,v
retrieving revision 1.8
diff -u -3 -p -r1.8 VMThread.java
--- vm/reference/java/lang/VMThread.java        2 Jul 2005 20:33:08 -0000       
1.8
+++ vm/reference/java/lang/VMThread.java        1 Nov 2005 18:17:46 -0000
@@ -376,15 +376,11 @@ final class VMThread
      */
     static void sleep(long ms, int ns) throws InterruptedException
     {
-
-      // Round up
-      ms += (ns != 0) ? 1 : 0;
-
       // Note: JDK treats a zero length sleep is like Thread.yield(),
       // without checking the interrupted status of the thread.
       // It's unclear if this is a bug in the implementation or the spec.
       // See http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6213203
-      if (ms == 0)
+      if (ms == 0 && ns == 0)
        {
          if (Thread.interrupted())
            throw new InterruptedException();
@@ -404,11 +400,12 @@ final class VMThread
        {
          while (true)
            {
-             vt.wait(ms);
+             vt.wait(ms, ns);
              now = System.currentTimeMillis();
              if (now >= end)
                break;
              ms = end - now;
+             ns = 0;
            }
        }
     }