RFR (S): 8139801: Error message from validation check has wrong order on Windows (original) (raw)

Chris Plummer chris.plummer at oracle.com
Tue Oct 20 23:35:22 UTC 2015

Hi Sangheon,

Thanks for doing this. A few comments/suggestions:

I don't think the #ifdef WIN32 should be needed. Although we are doing the fflush mainly to address issues we only currently see on win32, there's no reason why the fflush can't be done on all platforms. I think that will help keep the code cleaner.

In jni.cpp, is there a reason not to flush unconditionally (outside the if/else)?

Please make sure your commit comment references all 3 CRs this fix is addressing:

8139374 TlabSize.java argument test fails 8078328 AppCDS jtreg test result missing expected error message in stderr 8139801 Error message from validation check has wrong order on Windows

I'm not a "R"eviewer.

thanks,

Chris

On 10/20/15 3:03 PM, sangheon.kim wrote:

Hi all,

Initially I only tested validation error messages but later I noticed that other error messages also have same problem on Windows. (thanks to Chris Plummer for the discussion) When we fail to create VM, we end with 1) returning to the caller or 2) call vmabort(). For the 1) case, all error messages have wrong order on Windows. eg) an error message on Windows. (this is NG) $ java -XX:VMOptionsFile=foo -XX:VMOptionsFile=bar Error: Could not create the Java Virtual Machine. Error: A fatal exception has occurred. Program will exit. Only one VM Options file is supported on the command line <- this should be printed first. We can see easily this wrong order on Windows but the problem is there's no guarantee that 'stdout/stderr' will be flushed on that situation. As a solution I added fflush(stdout) and fflush(stderr) for above two cases. CR: https://bugs.openjdk.java.net/browse/JDK-8139801 Webrev: http://cr.openjdk.java.net/%7Esangheki/8139801/webrev.01/ Testing: JPRT Thanks, Sangheon

On 10/19/2015 01:00 PM, sangheon.kim wrote: Hi all again,

Let me cancel this patch as this kind of problem seems general on Windows. Thanks, Sangheon

On 10/19/2015 08:56 AM, sangheon.kim wrote: Hi all, Can I get some reviews for this change of adding 'fflush()' on validation message print? The order of 'validation error message' and 'vm exit message' is wrong on Windows. - Windows is buffering the validation error message which is sent to 'stderr'. - 'stderr' from 'jvm.dll' is flushed later than 'stderr' from the caller of 'jvm.dll'. eg) Expected message order (all other platforms except Windows) $ java -XX:MinTLABSize=1 -version 1) MinTLABSize (1) must be greater than or equal to reserved area in TLAB (16) 2) Error: Could not create the Java Virtual Machine. \n Error: A fatal exception has occurred. Program will exit. On Windows: $ java -XX:MinTLABSize=1 -version 2) Error: Could not create the Java Virtual Machine. \n Error: A fatal exception has occurred. Program will exit. 1) MinTLABSize (1) must be greater than or equal to reserved area in TLAB (16) As a solution, I added 'fflush()' on print function of validation check (CommandLineError::print). And any other functions that are printing to 'stderr' would have similar fix for Windows. CR: https://bugs.openjdk.java.net/browse/JDK-8139801 Webrev: http://cr.openjdk.java.net/~sangheki/8139801/webrev.00/ Testing: JPRT Thanks, Sangheon

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