[jira] [Created] (THRIFT-4469) isServing is not thread safe

["Robert Joseph Evans (JIRA)" <ji...@apache.org>]

Robert Joseph Evans created THRIFT-4469:
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             Summary: isServing is not thread safe
                 Key: THRIFT-4469
                 URL: https://issues.apache.org/jira/browse/THRIFT-4469
             Project: Thrift
          Issue Type: Bug
          Components: Java - Library
    Affects Versions: 0.11.0, 0.10.0, 0.9.3, 0.12.0, 1.0
            Reporter: Robert Joseph Evans


We have some integration tests in storm were we create a TServer and call serve on it in a background thread, because it is a blocking call.

Then in the main thread we wait for up to 10 seconds for isServing to return success with a 100ms sleep in between each call.

I don't know if this is a java bug or what, but in some not so rare cases isServing does not return true during the entire 10 seconds and the test fails.  The test prints out a stack trace when this happens and the background thread running the server is always at

https://github.com/apache/thrift/blob/b636ffb613ab49e0f037fbe696d28a4b17a72c5f/lib/java/src/org/apache/thrift/server/AbstractNonblockingServer.java#L95

happily serving.

So either we got very unlucky many times and it takes just a few ms longer than 10 seconds to come up some times, and < 1 sec other times, or java is doing something strange some of the time, and because Server.isServing is not volatile the checking thread caches a copy of it in a register and never updates it during the 10 seconds of the test run.

Even if it is a java bug, which I could argue probably is, it would be good to make isServing volatile.



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