RFR: 8150103: Convert TraceClassPaths to Unified Logging
Max Ockner
max.ockner at oracle.com
Fri Feb 19 20:11:12 UTC 2016
I have responded to these suggestions.
New webrev: http://cr.openjdk.java.net/~mockner/classpath.05/
- ClassLoader::trace_class_path() no longer takes a stream argument.
Because the body of trace_class_path is guarded by the classpath tag
(formerly TraceClassPaths), the output should always go to
LogHandle(classpath)::info_stream().
- SharedPathMiscInfo::trace_class_path() has been removed since it is
now redundant. Its only purpose was to call trace_class_path on tty.
ClassLoader::trace_class_path is now called in its place.
- print_path() no longer takes a stream argument. It now prints to
LogHandle(classpath)::info_stream().
- Accessing LogHandle(classpath)::info_stream() was causing issues
with the nonexistant current thread in arguments.cpp, so the single
logging statement in arguments.cpp was moved to classLoader.cpp.
Thanks,
Max
On 2/18/2016 7:28 AM, David Holmes wrote:
> 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/
>
> src/share/vm/classfile/classLoader.cpp
>
> This call:
>
> 477 trace_class_path(tty, "[Bootstrap loader class path=",
> sys_class_path);
>
> shouldn't be passing tty but should be the outputstream for the "info"
> log.
>
> ---
>
> src/share/vm/runtime/arguments.cpp
>
> Same here:
>
> if (!PrintSharedArchiveAndExit) {
> ClassLoader::trace_class_path(tty, "[classpath: ",
> _java_class_path->value());
> }
>
> ---
>
> src/share/vm/classfile/sharedPathsMiscInfo.hpp
>
> 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.
>
> David
> ----
>
>
>> 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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