8218565: HandleMark cleanup

Reviewed-by: coleenp, kbarrett, rehn

src/hotspot/share/runtime/handles.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,7 +26,6 @@
 #include "memory/allocation.inline.hpp"
 #include "oops/constantPool.hpp"
 #include "oops/oop.inline.hpp"
-#include "runtime/atomic.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/thread.inline.hpp"
 
@@ -102,9 +101,6 @@ static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
   return handles_visited;
 }
 
-// Used for debugging handle allocation.
-NOT_PRODUCT(jint _nof_handlemarks  = 0;)
-
 void HandleArea::oops_do(OopClosure* f) {
   uintx handles_visited = 0;
   // First handle the current chunk. It is filled to the high water mark.
@@ -130,46 +126,35 @@ void HandleMark::initialize(Thread* thread) {
   _size_in_bytes = _area->_size_in_bytes;
   debug_only(_area->_handle_mark_nesting++);
   assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
-  debug_only(Atomic::inc(&_nof_handlemarks);)
 
   // Link this in the thread
   set_previous_handle_mark(thread->last_handle_mark());
   thread->set_last_handle_mark(this);
 }
 
-
 HandleMark::~HandleMark() {
-  HandleArea* area = _area;   // help compilers with poor alias analysis
-  assert(area == _thread->handle_area(), "sanity check");
-  assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
-  debug_only(area->_handle_mark_nesting--);
+  assert(_area == _thread->handle_area(), "sanity check");
+  assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
 
-  // Delete later chunks
-  if( _chunk->next() ) {
-    // reset arena size before delete chunks. Otherwise, the total
-    // arena size could exceed total chunk size
-    assert(area->size_in_bytes() > size_in_bytes(), "Sanity check");
-    area->set_size_in_bytes(size_in_bytes());
-    _chunk->next_chop();
-  } else {
-    assert(area->size_in_bytes() == size_in_bytes(), "Sanity check");
-  }
-  // Roll back arena to saved top markers
-  area->_chunk = _chunk;
-  area->_hwm = _hwm;
-  area->_max = _max;
+  pop_and_restore();
 #ifdef ASSERT
   // clear out first chunk (to detect allocation bugs)
   if (ZapVMHandleArea) {
     memset(_hwm, badHandleValue, _max - _hwm);
   }
-  Atomic::dec(&_nof_handlemarks);
 #endif
 
   // Unlink this from the thread
   _thread->set_last_handle_mark(previous_handle_mark());
 }
 
+void HandleMark::chop_later_chunks() {
+  // reset arena size before delete chunks. Otherwise, the total
+  // arena size could exceed total chunk size
+  _area->set_size_in_bytes(size_in_bytes());
+  _chunk->next_chop();
+}
+
 void* HandleMark::operator new(size_t size) throw() {
   return AllocateHeap(size, mtThread);
 }

src/hotspot/share/runtime/handles.hpp

@@ -253,6 +253,8 @@ class HandleMark {
   HandleMark* previous_handle_mark() const        { return _previous_handle_mark; }
 
   size_t size_in_bytes() const { return _size_in_bytes; }
+  // remove all chunks beginning with the next
+  void chop_later_chunks();
  public:
   HandleMark();                            // see handles_inline.hpp
   HandleMark(Thread* thread)                      { initialize(thread); }

src/hotspot/share/runtime/handles.inline.hpp

@@ -79,7 +79,6 @@ inline HandleMark::HandleMark() {
   initialize(Thread::current());
 }
 
-
 inline void HandleMark::push() {
   // This is intentionally a NOP. pop_and_restore will reset
   // values to the HandleMark further down the stack, typically
@@ -88,22 +87,18 @@ inline void HandleMark::push() {
 }
 
 inline void HandleMark::pop_and_restore() {
-  HandleArea* area = _area;   // help compilers with poor alias analysis
   // Delete later chunks
-  if( _chunk->next() ) {
-    // reset arena size before delete chunks. Otherwise, the total
-    // arena size could exceed total chunk size
-    assert(area->size_in_bytes() > size_in_bytes(), "Sanity check");
-    area->set_size_in_bytes(size_in_bytes());
-    _chunk->next_chop();
+  if(_chunk->next() != NULL) {
+    assert(_area->size_in_bytes() > size_in_bytes(), "Sanity check");
+    chop_later_chunks();
   } else {
-    assert(area->size_in_bytes() == size_in_bytes(), "Sanity check");
+    assert(_area->size_in_bytes() == size_in_bytes(), "Sanity check");
   }
   // Roll back arena to saved top markers
-  area->_chunk = _chunk;
-  area->_hwm = _hwm;
-  area->_max = _max;
-  debug_only(area->_handle_mark_nesting--);
+  _area->_chunk = _chunk;
+  _area->_hwm = _hwm;
+  _area->_max = _max;
+  debug_only(_area->_handle_mark_nesting--);
 }
 
 inline HandleMarkCleaner::HandleMarkCleaner(Thread* thread) {