Bug ID: JDK-8257118 Obsolete the long term deprecated and aliased Trace flags

Type: CSR
Component: hotspot
Sub-Component: runtime

Priority: P4
Status: Closed
Resolution: Approved
Fix Versions: 16

Submitted: 2020-11-25
Updated: 2020-12-04
Resolved: 2020-11-30

Summary
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The following trace flags were deprecated in previous releases and should be obsolesced in JDK-16.  Users can get the same tracing information that was provided by these flags by using unified logging flags.

Trace flags deprecated in JDK-9:

 - TraceExceptions
 - TraceClassLoading
 - TraceClassLoadingPreorder
 - TraceClassUnloading
 - TraceClassPaths
 - TraceClassResolution
 - TraceLoaderConstraints
 - TraceSafepointCleanupTime
 - TraceBiasedLocking
 - TraceMonitorInflation
 - TraceRedefineClasses
 - TraceJVMTIObjectTagging

Trace flag PrintSharedSpaces was deprecated in JDK-10, PrintJNIResolving in JDK-14, and TraceInvokeDynamic and TraceMethodHandles in JDK-15.

Problem
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JVM trace flags that were deprecated in previous releases should be obsolesced in JDK-16.

Solution
--------

By obsoleting these flags, the JVM will no longer translate the flags into their unified logging alternative.  Instead, the JVM will ignore these flags.

Specification
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The descriptions of the above flags will be moved from the Deprecated Java Options section of the Java man page to the Obsolete Java Options section.

Re-affirming Approval after change in proposal.
04-12-2020
Because of objections during the code review, the 'obsoleted' messages for these flags will not say which -Xlog:... flags to use in place of the obsoleted trace flags.
03-12-2020
Moving to Approved.
30-11-2020
Thanks Coleen. I added release note sub-task: https://bugs.openjdk.java.net/browse/JDK-8257429
30-11-2020
I think there should be a release note for -XX:+TraceClassLoading, -XX:+TraceClassUnloading and -XX:+TraceExceptions though. People have used those.
30-11-2020