Summary

Obsolete the VM product option RefDiscoveryPolicy due to removal of the corresponding functionality.

Problem

RefDiscoveryPolicy accepts two values:

• 0: ReferenceBasedDiscovery (default)
• 1: ReferentBasedDiscovery

The non-default one is incorrectly implemented, but properly supporting it in Serial/Parallel/G1 is non-trivial. Since the default policy works fine and there is no observed inefficiency in reference-discovery using various benchmarks, it's best to remove the defective policy for now.

Solution

Obsolete RefDiscoveryPolicy without any deprecation period.

Specification

-  product(intx, RefDiscoveryPolicy, 0,                                      \
-          "Select type of reference discovery policy: "                     \
-          "reference-based(0) or referent-based(1)")                        \
-          range(ReferenceProcessor::DiscoveryPolicyMin,                     \
-                ReferenceProcessor::DiscoveryPolicyMax)                     \
-                                                                            \