RFR 8208715: Conversion of milliseconds to nanoseconds in UNIXProcess contains bug (original) (raw)

Martin Buchholz martinrb at google.com
Tue Aug 14 17:22:17 UTC 2018

Thanks, Roger. I approve this version, although as always I have comments.

520 private static native void waitForTimeoutInterruptibly( 521 long handle, long timeout);

The units being used should be obvious from the signature - rename timeout to timeoutMillis. But even better is to push the support for nanos into the utility method, so change this native method to accept a timeoutNanos.

2465 Thread.sleep(1000);

I hate sleeps, and I would just delete this one - I don't think the test relies on it (and if it did, one second is not long enough!).

2454 try { 2455 aboutToWaitFor.countDown(); 2456 boolean result = p.waitFor(Long.MAX_VALUE, TimeUnit.MILLISECONDS); 2457 fail("waitFor() wasn't interrupted, its return value was: " + result); 2458 } catch (InterruptedException success) { 2459 } catch (Throwable t) { unexpected(t); }

It's easy to add a self-interrupt variant inside the run method

Thread.currentThread().interrupt(); ...

(TODO: Basic.java is in need of a re-write - mea culpa ...)

On Tue, Aug 14, 2018 at 9:48 AM, Roger Riggs <Roger.Riggs at oracle.com> wrote:

Hi Martin,

I updated the webrev with the suggestions. On 8/14/2018 10:47 AM, Martin Buchholz wrote: hi Roger, 509 if (deadline <= 0) { 510 deadline = Long.MAXVALUE; 511 }

This must be wrong. Nanotime wraparound is normal in this sort of code. ok, this reader didn't make that assumption --- We ought to be able to delegate the fiddling with nanos to TimeUnit.timedWait. Does it work to simply call NANOSECONDS.timedWait(remainingNanos) ? If not, is there a bug in TimeUnit.timedWait? That works except on Windows, that does not use wait(). It's good to add a test for this. I've tried hard in similar tests to avoid sleep and to add variants where the target thread is interrupted before and after starting to wait. Testing pre-interrupt is easy - the thread can interrupt itself. BlockingQueueTest.testTimedPollWithOffer is an example. I added a test, using the same logic as the existing tests for the Long.MAXVALUE case Thanks, Roger

On Tue, Aug 14, 2018 at 7:00 AM, Roger Riggs <Roger.Riggs at oracle.com> wrote: Please review a fix for Process.waitFor(Long.MAXVALUE,MILLIS). Catch wrap around in very large wait times and saturate at Long.MAXVALUE. Webrev: http://cr.openjdk.java.net/~rriggs/webrev-timeout-8208715/ Issue: https://bugs.openjdk.java.net/browse/JDK-8208715 Thanks, Roger

More information about the core-libs-dev mailing list