--- old/src/hotspot/share/gc/g1/dirtyCardQueue.cpp	2019-01-08 20:21:33.360154114 -0500
+++ new/src/hotspot/share/gc/g1/dirtyCardQueue.cpp	2019-01-08 20:21:33.108140820 -0500
@@ -79,6 +79,10 @@
   _all_active = true;
 }
 
+DirtyCardQueueSet::~DirtyCardQueueSet() {
+  delete _free_ids;
+}
+
 // Determines how many mutator threads can process the buffers in parallel.
 uint DirtyCardQueueSet::num_par_ids() {
   return (uint)os::initial_active_processor_count();
--- old/src/hotspot/share/gc/g1/dirtyCardQueue.hpp	2019-01-08 20:21:34.216199270 -0500
+++ new/src/hotspot/share/gc/g1/dirtyCardQueue.hpp	2019-01-08 20:21:33.968186187 -0500
@@ -117,6 +117,7 @@
 
 public:
   DirtyCardQueueSet(bool notify_when_complete = true);
+  ~DirtyCardQueueSet();
 
   void initialize(Monitor* cbl_mon,
                   BufferNode::Allocator* allocator,
--- old/src/hotspot/share/gc/g1/g1FreeIdSet.cpp	2019-01-08 20:21:35.120246957 -0500
+++ new/src/hotspot/share/gc/g1/g1FreeIdSet.cpp	2019-01-08 20:21:34.868233664 -0500
@@ -30,8 +30,6 @@
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/macros.hpp"
 
-const uint claimed = UINT_MAX;
-
 G1FreeIdSet::G1FreeIdSet(uint start, uint size) :
   _sem(size),          // counting semaphore for available ids
   _next(NULL),         // array of "next" indices
@@ -68,6 +66,8 @@
   return index | ((old_head & ~_head_index_mask) + 1 + _head_index_mask);
 }
 
+const uint Claimed = UINT_MAX;
+
 uint G1FreeIdSet::claim_par_id() {
   _sem.wait();
   // Semaphore gate permits passage by no more than the number of
@@ -83,14 +83,14 @@
     if (new_head == old_head) break;
     old_head = new_head;
   }
-  DEBUG_ONLY(_next[index] = claimed;)
+  DEBUG_ONLY(_next[index] = Claimed;)
   return _start + index;
 }
 
 void G1FreeIdSet::release_par_id(uint id) {
   uint index = id - _start;
   assert(index < _size, "invalid id %u", id);
-  assert(_next[index] == claimed, "precondition");
+  assert(_next[index] == Claimed, "precondition");
   uintx old_head = Atomic::load(&_head);
   while (true) {
     _next[index] = head_index(old_head);
--- old/src/hotspot/share/gc/g1/g1FreeIdSet.hpp	2019-01-08 20:21:36.104298865 -0500
+++ new/src/hotspot/share/gc/g1/g1FreeIdSet.hpp	2019-01-08 20:21:35.816283673 -0500
@@ -29,7 +29,11 @@
 #include "runtime/semaphore.hpp"
 #include "utilities/globalDefinitions.hpp"
 
-// Represents a set of free small integer ids.
+// Represents a set of small integer ids, from which elements can be
+// temporarily allocated for exclusive use.  The ids are in a
+// contiguous range from 'start' to 'start + size'.  Used to obtain a
+// distinct worker_id value for a mutator thread that doesn't normally
+// have such an id.
 class G1FreeIdSet : public CHeapObj<mtGC> {
   Semaphore _sem;
   uint* _next;