--- old/src/hotspot/share/gc/shenandoah/shenandoahRootProcessor.cpp	2020-06-01 12:25:22.525029055 +0200
+++ new/src/hotspot/share/gc/shenandoah/shenandoahRootProcessor.cpp	2020-06-01 12:25:22.213029460 +0200
@@ -202,7 +202,7 @@
   _code_roots(phase),
   _vm_roots(phase),
   _dedup_roots(phase),
-  _cld_roots(phase) {
+  _cld_roots(phase, n_workers) {
 }
 
 void ShenandoahRootScanner::roots_do(uint worker_id, OopClosure* oops) {
@@ -234,9 +234,9 @@
    // Process light-weight/limited parallel roots then
   _vm_roots.oops_do(oops, worker_id);
   _dedup_roots.oops_do(&always_true, oops, worker_id);
+  _cld_roots.cld_do(clds, worker_id);
 
   // Process heavy-weight/fully parallel roots the last
-  _cld_roots.cld_do(clds, worker_id);
   _thread_roots.threads_do(&tc_cl, worker_id);
 }
 
@@ -251,9 +251,9 @@
 
   // Process light-weight/limited parallel roots then
   _vm_roots.oops_do(oops, worker_id);
+  _cld_roots.always_strong_cld_do(clds, worker_id);
 
   // Process heavy-weight/fully parallel roots the last
-  _cld_roots.always_strong_cld_do(clds, worker_id);
   _thread_roots.threads_do(&tc_cl, worker_id);
 }
 
@@ -264,7 +264,7 @@
   ShenandoahRootProcessor(phase),
   _serial_roots(phase),
   _vm_roots(phase),
-  _cld_roots(phase),
+  _cld_roots(phase, n_workers),
   _thread_roots(phase, n_workers > 1),
   _serial_weak_roots(phase),
   _weak_roots(phase),
@@ -292,11 +292,13 @@
     _weak_roots.oops_do<OopClosure>(oops, worker_id);
     _dedup_roots.oops_do(&always_true, oops, worker_id);
   }
-
-  // Process heavy-weight/fully parallel roots the last
   if (_stw_class_unloading) {
     CLDToOopClosure clds(oops, ClassLoaderData::_claim_strong);
     _cld_roots.cld_do(&clds, worker_id);
+  }
+
+  // Process heavy-weight/fully parallel roots the last
+  if (_stw_class_unloading) {
     _code_roots.code_blobs_do(codes_cl, worker_id);
     _thread_roots.oops_do(oops, NULL, worker_id);
   } else {
@@ -308,7 +310,7 @@
   ShenandoahRootProcessor(phase),
   _serial_roots(phase),
   _vm_roots(phase),
-  _cld_roots(phase),
+  _cld_roots(phase, n_workers),
   _thread_roots(phase, n_workers > 1),
   _serial_weak_roots(phase),
   _weak_roots(phase),
@@ -320,7 +322,7 @@
   ShenandoahRootProcessor(phase),
   _serial_roots(phase),
   _vm_roots(phase),
-  _cld_roots(phase),
+  _cld_roots(phase, n_workers),
   _thread_roots(phase, n_workers > 1),
   _serial_weak_roots(phase),
   _weak_roots(phase),
@@ -346,9 +348,9 @@
   _vm_roots.oops_do(oops, worker_id);
   _weak_roots.oops_do<OopClosure>(oops, worker_id);
   _dedup_roots.oops_do(&always_true, oops, worker_id);
+  _cld_roots.cld_do(&adjust_cld_closure, worker_id);
 
   // Process heavy-weight/fully parallel roots the last
-  _cld_roots.cld_do(&adjust_cld_closure, worker_id);
   _code_roots.code_blobs_do(adjust_code_closure, worker_id);
   _thread_roots.oops_do(oops, NULL, worker_id);
 }
@@ -358,7 +360,7 @@
    _serial_roots(ShenandoahPhaseTimings::heap_iteration_roots),
    _thread_roots(ShenandoahPhaseTimings::heap_iteration_roots, false /*is par*/),
    _vm_roots(ShenandoahPhaseTimings::heap_iteration_roots),
-   _cld_roots(ShenandoahPhaseTimings::heap_iteration_roots),
+   _cld_roots(ShenandoahPhaseTimings::heap_iteration_roots, 1),
    _serial_weak_roots(ShenandoahPhaseTimings::heap_iteration_roots),
    _weak_roots(ShenandoahPhaseTimings::heap_iteration_roots),
    _code_roots(ShenandoahPhaseTimings::heap_iteration_roots) {
@@ -382,9 +384,9 @@
    _vm_roots.oops_do(oops, 0);
    _weak_roots.oops_do<OopClosure>(oops, 0);
    _dedup_roots.oops_do(&always_true, oops, 0);
+   _cld_roots.cld_do(&clds, 0);
 
    // Process heavy-weight/fully parallel roots the last
-   _cld_roots.cld_do(&clds, 0);
    _code_roots.code_blobs_do(&code, 0);
    _thread_roots.threads_do(&tc_cl, 0);
  }