[9] RFR(S): 8150441: CompileTask::print_impl() is broken after JDK-8146905

[David Holmes]

Hi Tobias,

On 23/02/2016 8:19 PM, Tobias Hartmann wrote:
> Hi,
>
> please review the following patch.
>
> https://bugs.openjdk.java.net/browse/JDK-8150441
> http://cr.openjdk.java.net/~thartmann/8150441/webrev.00/
>
> The fix for JDK-8146905 [1] removed staticBufferStream and instead passes VMError::out/log to CompileTask::print_line_on_error() to print the current compile task if an error occurs. The problem is that fdStream VMError::out/log does not initialize the TimeStamp outputStream::_stamp and we hit the "must not be clear" assert in TimeStamp::milliseconds() which is called from CompileTask::print_impl(). Before, the TimeStamp was initialized in the staticBufferStream constructor [2].

I find the original code difficult to follow. The staticBufferStream did 
initialize its own stamp, but AFAICS that stamp is never used in 
relation to the wrapped outer-stream, so somehow that stamp must have 
been exposed through one of the methods that didn't delegate to the 
outer stream ??

> The time stamps should be explicitly initialized like we do in ostream_init(). I verified that my patch solves the problem.

Why is the timestamp of a stream not initialized when the stream is 
constructed? Why are we deferring it until report_and_die() ?

Thanks,
David

> Thanks,
> Tobias
>
> [1] http://hg.openjdk.java.net/jdk9/hs-rt/hotspot/rev/64ba9950558b
> [2] http://hg.openjdk.java.net/jdk9/hs-rt/hotspot/rev/64ba9950558b#l1.102
>