98     if (_generation->is_young()) {
 99       // But only scan the remembered set for young generation.
100       _generation->scan_remembered_set(false /* is_concurrent */);
101     }
102 
103     ShenandoahSTWMarkTask task(this);
104     heap->workers()->run_task(&task);
105 
106     assert(task_queues()->is_empty(), "Should be empty");
107 
108     if (!generation()->is_old()) {
109       // Lastly, ensure all the invisible roots are marked.
110       ShenandoahInvisibleRootsMarkClosure cl;
111       Threads::java_threads_do(&cl);
112     }
113   }
114 
115   _generation->set_mark_complete();
116   end_mark();
117 
118   // Mark is finished, can disarm the nmethods now.
119   ShenandoahCodeRoots::disarm_nmethods();
120 
121   assert(task_queues()->is_empty(), "Should be empty");
122   TASKQUEUE_STATS_ONLY(task_queues()->print_and_reset_taskqueue_stats(""));
123 }
124 
125 void ShenandoahSTWMark::mark_roots(uint worker_id) {
126   ShenandoahReferenceProcessor* rp = _generation->ref_processor();
127   auto queue = task_queues()->queue(worker_id);
128   switch (_generation->type()) {
129     case NON_GEN: {
130       ShenandoahMarkRefsClosure<NON_GEN> init_mark(queue, rp, nullptr);
131       _root_scanner.roots_do(&init_mark, worker_id);
132       break;
133     }
134     case GLOBAL: {
135       ShenandoahMarkRefsClosure<GLOBAL> init_mark(queue, rp, nullptr);
136       _root_scanner.roots_do(&init_mark, worker_id);
137       break;
138     }
139     case YOUNG: {
140       ShenandoahMarkRefsClosure<YOUNG> init_mark(queue, rp, nullptr);

 98     if (_generation->is_young()) {
 99       // But only scan the remembered set for young generation.
100       _generation->scan_remembered_set(false /* is_concurrent */);
101     }
102 
103     ShenandoahSTWMarkTask task(this);
104     heap->workers()->run_task(&task);
105 
106     assert(task_queues()->is_empty(), "Should be empty");
107 
108     if (!generation()->is_old()) {
109       // Lastly, ensure all the invisible roots are marked.
110       ShenandoahInvisibleRootsMarkClosure cl;
111       Threads::java_threads_do(&cl);
112     }
113   }
114 
115   _generation->set_mark_complete();
116   end_mark();
117 



118   assert(task_queues()->is_empty(), "Should be empty");
119   TASKQUEUE_STATS_ONLY(task_queues()->print_and_reset_taskqueue_stats(""));
120 }
121 
122 void ShenandoahSTWMark::mark_roots(uint worker_id) {
123   ShenandoahReferenceProcessor* rp = _generation->ref_processor();
124   auto queue = task_queues()->queue(worker_id);
125   switch (_generation->type()) {
126     case NON_GEN: {
127       ShenandoahMarkRefsClosure<NON_GEN> init_mark(queue, rp, nullptr);
128       _root_scanner.roots_do(&init_mark, worker_id);
129       break;
130     }
131     case GLOBAL: {
132       ShenandoahMarkRefsClosure<GLOBAL> init_mark(queue, rp, nullptr);
133       _root_scanner.roots_do(&init_mark, worker_id);
134       break;
135     }
136     case YOUNG: {
137       ShenandoahMarkRefsClosure<YOUNG> init_mark(queue, rp, nullptr);