Summary
-------
Deprecate the unstable HotSpot option -XX:SafepointSpinBeforeYield=??.
Problem
-------
The option have no information to user to what it does except "(Unstable)".
A user should not try to change this option, hence unstable.
The method SafepointSynchronize::begin have become really large and complicated.
For future refactoring of this method we should now deprecate this options.
Solution
--------
Deprecate the flag.
Specification
-------------
diff -r 7092940fbaff src/hotspot/share/runtime/arguments.cpp
--- a/src/hotspot/share/runtime/arguments.cpp Wed Nov 15 08:25:28 2017 -0500
+++ b/src/hotspot/share/runtime/arguments.cpp Wed Nov 15 15:38:43 2017 +0100
@@ -387,2 +387,3 @@
{ "FastTLABRefill", JDK_Version::jdk(10), JDK_Version::jdk(11), JDK_Version::jdk(12) },
+ { "SafepointSpinBeforeYield", 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 7092940fbaff src/hotspot/share/runtime/globals.hpp
--- a/src/hotspot/share/runtime/globals.hpp Wed Nov 15 08:25:28 2017 -0500
+++ b/src/hotspot/share/runtime/globals.hpp Wed Nov 15 15:38:43 2017 +0100
@@ -3278,3 +3278,3 @@
\
- product(intx, SafepointSpinBeforeYield, 2000, "(Unstable)") \
+ product(intx, SafepointSpinBeforeYield, 2000, "(Unstable, Deprecated)") \
range(0, max_intx) \