RFR: 8150103: Convert TraceClassPaths to Unified Logging

David Holmes david.holmes at oracle.com
Thu Feb 18 12:28:05 UTC 2016

Hi Max,

This conversion is not straight-forward, and not complete.

On 18/02/2016 8:19 AM, Max Ockner wrote:
> Hello everyone,
> Please review this conversion of TraceClassPaths to UL.
> Bug: https://bugs.openjdk.java.net/browse/JDK-8150103
> Webrev: http://cr.openjdk.java.net/~mockner/classpath.03/


This call:

  477     trace_class_path(tty, "[Bootstrap loader class path=", 

shouldn't be passing tty but should be the outputstream for the "info" log.



Same here:

   if (!PrintSharedArchiveAndExit) {
     ClassLoader::trace_class_path(tty, "[classpath: ", 



You didn't modify this file but you need to change the 2-arg 
trace_class_path() to not use the tty.

This conversion seems a bit problematic to me. trace_class_path was 
enabled/disabled via TraceClassPaths, but it could write to different 
output streams. With UL you would always want it to write to the single 
UL related stream - which means the API really needs to change, and the 
extraction of the correct log stream can then be internalized. But there 
may be some compatibility issues in doing that for the place(s) where it 
may not be writing to tty.

I don't see a simple conversion process here. I think all 
trace_class_path calls should be the two-arg forms with no stream arg, 
and that version then inlines the current 3-arg version but always 
writes to the info log stream. But then you also have print_path which 
wraps a call to trace_class_path ... to be honest I don't see what 
purpose print_path serves, it just seems to be complicating things.


> Summary:  TraceClassPaths flag has been reimplemented using the
> classpath tag with Info level.  TraceClassPaths has been added to the
> logging alias table.
> There is some related output that was never guarded by "if
> (TraceClassPaths)", so it has not been included in this conversion.
> Testing: jtreg runtime tests. Added basic test case at
> test/runtime/logging/ClassPathTest.java
> Thanks,
> Max

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