On 13.5.2015 19:40, Martin Buchholz wrote:
toString()should never return null, I think.

It doesn't matter much here. The test would fail with an NPE and it would be right to do so. None of the suppliers should ever return null.


   52         @Override
   53         public String toString() {
   54             T resolved = val.get();
   55             return resolved != null ? resolved.toString() : null;
   56         }


I expected methods like waitForCondition to include a timeout with
failure.  I like 10 seconds, being large enough to never be hit
spuriously in tests.

It's difficult to find a value 'large enough'. Imagine the test running on a small embedded device and fastdebug build. I had my fun fixing tests failing intermittently because it was thought that the original timeout was large enough. I better leave it to the harness.


Why not
() -> (long) mbean.getThreadCount(),

Because curLiveThreadCount needs to be set to mbean.getThreadCount() value.


  169             ()->{
  170                 curLiveThreadCount = mbean.getThreadCount();
  171                 return (long)curLiveThreadCount;
  172             },


I worry that
mbean.getThreadCount()
is hard to test since the "system" may spin up and shut down utility
threads at any time.

The 'system' threads are not reported by this method. And the current understanding is that once VM is fully initialized no user-observable threads are randomly started on behalf of the system.

-JB-


On Wed, May 13, 2015 at 4:46 AM, Jaroslav Bachorik
<jaroslav.bacho...@oracle.com <mailto:jaroslav.bacho...@oracle.com>> wrote:

    On 1.5.2015 21:55, Martin Buchholz wrote:



        On Thu, Apr 30, 2015 at 11:27 AM, Jaroslav Bachorik
        <jaroslav.bacho...@oracle.com
        <mailto:jaroslav.bacho...@oracle.com>
        <mailto:jaroslav.bacho...@oracle.com
        <mailto:jaroslav.bacho...@oracle.com>>> wrote:

             On 30.4.2015 19:18, Martin Buchholz wrote:

                 Tests that sleep can almost always be better written
        some other way.
                 In this case, I would prefer busy-waiting with timeout
        until the
                 expected condition becomes true.


             The thing is that in case of a real issue with the thread
        counters we
             a/ would be busy-waiting till the test times out (using an
        arbitrary
             delay is also problematic due to different performance of
        different
             machines running with different configurations)


        Far less problematic (performance-wise and reliability-wise)
        than the
        fixed sleep.

             b/ would get a rather confusing message about the test
        timing out at
             the end


        You can easily improve the error message.


    Well, not that easily. It is not possible to get a notification when
    JTREG decides to timeout the test. So you will get the standard
    JTREG message and that's all.

    I was able to modify the test to wait for a given condition and
    provide useful messages in case of mismatch and retry. For the price
    of an increased complexity. On the other hand, the test should be
    much more resilient to timing errors caused by slow setups.

    Updated webrev: http://cr.openjdk.java.net/~jbachorik/8078143/webrev.01

    Thanks,

    -JB-



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