Bug ID: JDK-8191331 Deprecate DeferThrSuspendLoopCount and start removal

Type: CSR
Component: hotspot
Sub-Component: runtime

Priority: P4
Status: Closed
Resolution: Approved
Fix Versions: 10

Submitted: 2017-11-15
Updated: 2017-11-21
Resolved: 2017-11-16

Summary
-------

Deprecate the unstable HotSpot option -XX:DeferThrSuspendLoopCount=??.

Problem
-------

The option will have no effect once we implement thread suspend with Thread-local handshakes.
A user should not try to change this option, hence unstable.

Solution
--------

Deprecate the flag.

Specification
-------------

    --- a/src/hotspot/share/runtime/arguments.cpp	Wed Nov 15 15:38:36 2017 +0100
    +++ b/src/hotspot/share/runtime/arguments.cpp	Wed Nov 15 16:24:54 2017 +0100
    @@ -388,2 +388,3 @@
       { "SafepointSpinBeforeYield",     JDK_Version::jdk(10), JDK_Version::jdk(11), JDK_Version::jdk(12) },
    +  { "DeferThrSuspendLoopCount",     JDK_Version::jdk(10), JDK_Version::jdk(11), JDK_Version::jdk(12) },
       { "IgnoreUnverifiableClassesDuringDump", JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
    diff -r fc697acd5cad src/hotspot/share/runtime/globals.hpp
    --- a/src/hotspot/share/runtime/globals.hpp	Wed Nov 15 15:38:36 2017 +0100
    +++ b/src/hotspot/share/runtime/globals.hpp	Wed Nov 15 16:24:54 2017 +0100
    @@ -3269,3 +3269,4 @@
       product(intx, DeferThrSuspendLoopCount,     4000,                         \
    -          "(Unstable) Number of times to iterate in safepoint loop "        \
    +          "(Unstable, Deprecated) "                                         \
    +          "Number of times to iterate in safepoint loop "                   \
               "before blocking VM threads ")                                    \

Presumably the release note intended in JDK-8191423 will cover all the related options being deprecated. Moving to approved.

16-11-2017

I assume that a release note will be created for this.

16-11-2017