diff a/src/hotspot/os/windows/os_perf_windows.cpp b/src/hotspot/os/windows/os_perf_windows.cpp
--- a/src/hotspot/os/windows/os_perf_windows.cpp
+++ b/src/hotspot/os/windows/os_perf_windows.cpp
@@ -223,13 +223,13 @@
   assert(process_query != NULL, "invariant");
   return allocate_counters(&process_query->set, nofCounters);
 }
 
 static void deallocate_counters(MultiCounterQueryP query) {
-    FREE_C_HEAP_ARRAY(char, query->counters);
-    query->counters = NULL;
-    query->noOfCounters = 0;
+  FREE_C_HEAP_ARRAY(char, query->counters);
+  query->counters = NULL;
+  query->noOfCounters = 0;
 }
 
 static OSReturn add_counter(UpdateQueryP query, HCOUNTER* counter, const char* path, bool first_sample_on_init) {
   assert(query != NULL, "invariant");
   assert(counter != NULL, "invariant");
diff a/src/hotspot/share/classfile/classLoader.cpp b/src/hotspot/share/classfile/classLoader.cpp
--- a/src/hotspot/share/classfile/classLoader.cpp
+++ b/src/hotspot/share/classfile/classLoader.cpp
@@ -381,13 +381,11 @@
 
 ClassPathImageEntry::~ClassPathImageEntry() {
   assert(_singleton == this, "must be");
   DEBUG_ONLY(_singleton = NULL);
 
-
   FREE_C_HEAP_ARRAY(const char, _name);
-  _name = NULL;
 
   if (_jimage != NULL) {
     (*JImageClose)(_jimage);
     _jimage = NULL;
   }
diff a/src/hotspot/share/gc/g1/sparsePRT.cpp b/src/hotspot/share/gc/g1/sparsePRT.cpp
--- a/src/hotspot/share/gc/g1/sparsePRT.cpp
+++ b/src/hotspot/share/gc/g1/sparsePRT.cpp
@@ -103,13 +103,11 @@
   clear();
 }
 
 RSHashTable::~RSHashTable() {
   FREE_C_HEAP_ARRAY(SparsePRTEntry, _entries);
-  _entries = NULL;
   FREE_C_HEAP_ARRAY(int, _buckets);
-  _buckets = NULL;
 }
 
 void RSHashTable::clear() {
   _occupied_entries = 0;
   _occupied_cards = 0;
diff a/src/hotspot/share/gc/shared/cardTableRS.cpp b/src/hotspot/share/gc/shared/cardTableRS.cpp
--- a/src/hotspot/share/gc/shared/cardTableRS.cpp
+++ b/src/hotspot/share/gc/shared/cardTableRS.cpp
@@ -623,19 +623,14 @@
   }
 }
 
 CardTableRS::~CardTableRS() {
   FREE_C_HEAP_ARRAY(CardValue, _last_cur_val_in_gen);
-  _last_cur_val_in_gen = NULL;
   FREE_C_HEAP_ARRAY(CardArr, _lowest_non_clean);
-  _lowest_non_clean = NULL;
   FREE_C_HEAP_ARRAY(size_t, _lowest_non_clean_chunk_size);
-  _lowest_non_clean_chunk_size = NULL;
   FREE_C_HEAP_ARRAY(uintptr_t, _lowest_non_clean_base_chunk_index);
-  _lowest_non_clean_base_chunk_index = NULL;
   FREE_C_HEAP_ARRAY(int, _last_LNC_resizing_collection);
-  _last_LNC_resizing_collection = NULL;
 }
 
 void CardTableRS::initialize() {
   CardTable::initialize();
   _lowest_non_clean =
diff a/src/hotspot/share/memory/allocation.cpp b/src/hotspot/share/memory/allocation.cpp
--- a/src/hotspot/share/memory/allocation.cpp
+++ b/src/hotspot/share/memory/allocation.cpp
@@ -62,10 +62,11 @@
     vm_exit_out_of_memory(size, OOM_MALLOC_ERROR, "ReallocateHeap");
   }
   return p;
 }
 
+// handles NULL pointers
 void FreeHeap(void* p) {
   os::free(p);
 }
 
 void* MetaspaceObj::_shared_metaspace_base = NULL;
diff a/src/hotspot/share/memory/allocation.hpp b/src/hotspot/share/memory/allocation.hpp
--- a/src/hotspot/share/memory/allocation.hpp
+++ b/src/hotspot/share/memory/allocation.hpp
@@ -182,10 +182,11 @@
 char* ReallocateHeap(char *old,
                      size_t size,
                      MEMFLAGS flag,
                      AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
 
+// handles NULL pointers
 void FreeHeap(void* p);
 
 template <MEMFLAGS F> class CHeapObj ALLOCATION_SUPER_CLASS_SPEC {
  public:
   ALWAYSINLINE void* operator new(size_t size) throw() {
diff a/src/hotspot/share/runtime/os.cpp b/src/hotspot/share/runtime/os.cpp
--- a/src/hotspot/share/runtime/os.cpp
+++ b/src/hotspot/share/runtime/os.cpp
@@ -794,11 +794,11 @@
   }
   return ptr;
 #endif
 }
 
-
+// handles NULL pointers
 void  os::free(void *memblock) {
   NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
 #ifdef ASSERT
   if (memblock == NULL) return;
   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
diff a/src/hotspot/share/runtime/os.hpp b/src/hotspot/share/runtime/os.hpp
--- a/src/hotspot/share/runtime/os.hpp
+++ b/src/hotspot/share/runtime/os.hpp
@@ -738,10 +738,11 @@
   static void* malloc  (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
   static void* malloc  (size_t size, MEMFLAGS flags);
   static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
   static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
 
+  // handles NULL pointers
   static void  free    (void *memblock);
   static char* strdup(const char *, MEMFLAGS flags = mtInternal);  // Like strdup
   // Like strdup, but exit VM when strdup() returns NULL
   static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
 
diff a/src/hotspot/share/runtime/thread.cpp b/src/hotspot/share/runtime/thread.cpp
--- a/src/hotspot/share/runtime/thread.cpp
+++ b/src/hotspot/share/runtime/thread.cpp
@@ -1327,11 +1327,10 @@
   _gc_id(GCId::undefined())
 {}
 
 NamedThread::~NamedThread() {
   FREE_C_HEAP_ARRAY(char, _name);
-  _name = NULL;
 }
 
 void NamedThread::set_name(const char* format, ...) {
   guarantee(_name == NULL, "Only get to set name once.");
   _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread);