8201646: Introduce ReferenceDiscoverer interface Reviewed-by: stefank, tschatzl, rkennke

8196071: Change G1 Full GC heap and thread sizing ergonomics Reviewed-by: tschatzl, sangheki

8200450: Root cause analysis for JDK-8200366 Summary: add safeguard checks to make sure CodeBlob if fully initialized Reviewed-by: kvn

8201556: Disallow reading oops in ClassLoaderData if unloading Summary: Move class_loader oop to an OopHandle, and assert that holder is alive when getting class_loader. Reviewed-by: kbarrett, adinn

8184693: add Pattern.isEmpty Summary: added method Pattern.isEmpty Reviewed-by: forax, chegar, smarks, psandoz, rriggs

8196433: use the new error diagnostic approach at javac.Main Reviewed-by: jjg

8201537: Remove is_alive closure from Klass::is_loader_alive() Summary: remove is_alive closure from callers of Klass::is_loader_alive so that cleaning metadata doesn't require GC closure. Reviewed-by: adinn, stefank

8201766: Mark TimSortStackSize2.java as intermittently failing Reviewed-by: dholmes

8201527: Bump default value of G1RefProcDrainInterval Summary: Due to high startup cost of marking, lower the frequency of draining the mark stack generated by reference processing. Reviewed-by: sangheki, sjohanss

8201505: Use WeakHandle for ProtectionDomainCacheTable and ResolvedMethodTable 8193524: Redefining a method that removes use of 1 or more lambda expressions causes the JVM to hang Summary: Remove oop pointers from runtime data structures. Reviewed-by: lfoltan, stefank Contributed-by: coleen.phillimore@oracle.com, lois.foltan@oracle.com

8201369: Inet4AddressImpl_getLocalHostName reverse lookup on Solaris only Reviewed-by: clanger, chegar Contributed-by: sshamaia@in.ibm.com

8200555: OopHandle should use Access API Summary: Add RootAccess<> to OopHandle.resolve() in runtime and interpreter code. Add comments for compiler code for later. Reviewed-by: eosterlund, stefank

8201794: [Graal] fix regressions from JDK-8187490 Reviewed-by: alanb, mchung

8198793: Add launcher support for preview features Reviewed-by: mchung, sundar

8201616: Hotspot crashes on linux-sparc after 8189941 Reviewed-by: kvn, stuefe

8201799: Build failures after JDK-8195099 (Concurrent safe-memory-reclamation mechanism) Reviewed-by: dholmes, tschatzl, eosterlund

8201172: Parallelize Remset Tracking Update Before Rebuild phase Reviewed-by: sangheki, sjohanss

8201596: java.lang.ref.Reference processing total time logging broken Summary: Fix "Reference Processing" and add "Weak Processing" time Reviewed-by: kbarrett, sangheki

8201490: Improve concurrent mark keep alive closure performance Summary: Avoid doing marking work unless absolutely required. Reviewed-by: sjohanss, kbarrett

8201487: Do not rebalance reference processing queues if not doing parallel reference processing Reviewed-by: sangheki, kbarrett

8200730: Fix debug=gc+phases time tracking in Remark and Cleanup Summary: Timing in Remark and Cleanup pauses did not use instance variables for the scoped timing objects, so these durations were always zero. Reviewed-by: sangheki, sjohanss

8200426: Make G1 code use _g1h members Summary: Consistently use _g1h member names for cached G1CollectedHeap* variables. Reviewed-by: sangheki, sjohanss

8200723: Suppress rs_length and predicted_cards sampling during mixed gcs Summary: Due to the impact of these measurements on pause time, their high difference to other collections during mixed collections, and their non-use during mixed collections, do not use rs_length and predicted_cards measurements done during mixed gc for the predictor. This avoids the young gen sizing after the mixed phase to be negatively affected by mixed collections. Reviewed-by: kbarrett, sjohanss

8154528: Reclaim regions emptied by marking in Remark pause Reviewed-by: shade, sjohanss