--- a/hotspot/src/share/vm/gc_implementation/shared/markSweep.cpp	Tue Sep 28 09:51:37 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/markSweep.cpp	Tue Sep 28 15:56:15 2010 -0700
@@ -25,13 +25,13 @@
 #include "incls/_precompiled.incl"
 #include "incls/_markSweep.cpp.incl"
 
-GrowableArray<oop>*          MarkSweep::_marking_stack = NULL;
-GrowableArray<ObjArrayTask>* MarkSweep::_objarray_stack = NULL;
-GrowableArray<Klass*>*       MarkSweep::_revisit_klass_stack = NULL;
-GrowableArray<DataLayout*>*  MarkSweep::_revisit_mdo_stack = NULL;
+Stack<oop>              MarkSweep::_marking_stack;
+Stack<DataLayout*>      MarkSweep::_revisit_mdo_stack;
+Stack<Klass*>           MarkSweep::_revisit_klass_stack;
+Stack<ObjArrayTask>     MarkSweep::_objarray_stack;
 
-GrowableArray<oop>*     MarkSweep::_preserved_oop_stack = NULL;
-GrowableArray<markOop>* MarkSweep::_preserved_mark_stack= NULL;
+Stack<oop>              MarkSweep::_preserved_oop_stack;
+Stack<markOop>          MarkSweep::_preserved_mark_stack;
 size_t                  MarkSweep::_preserved_count = 0;
 size_t                  MarkSweep::_preserved_count_max = 0;
 PreservedMark*          MarkSweep::_preserved_marks = NULL;
@@ -58,37 +58,42 @@
 #endif
 
 void MarkSweep::revisit_weak_klass_link(Klass* k) {
-  _revisit_klass_stack->push(k);
+  _revisit_klass_stack.push(k);
 }
 
 void MarkSweep::follow_weak_klass_links() {
   // All klasses on the revisit stack are marked at this point.
   // Update and follow all subklass, sibling and implementor links.
   if (PrintRevisitStats) {
-    gclog_or_tty->print_cr("#classes in system dictionary = %d", SystemDictionary::number_of_classes());
-    gclog_or_tty->print_cr("Revisit klass stack length = %d", _revisit_klass_stack->length());
+    gclog_or_tty->print_cr("#classes in system dictionary = %d",
+                           SystemDictionary::number_of_classes());
+    gclog_or_tty->print_cr("Revisit klass stack size = " SIZE_FORMAT,
+                           _revisit_klass_stack.size());
   }
-  for (int i = 0; i < _revisit_klass_stack->length(); i++) {
-    _revisit_klass_stack->at(i)->follow_weak_klass_links(&is_alive,&keep_alive);
+  while (!_revisit_klass_stack.is_empty()) {
+    Klass* const k = _revisit_klass_stack.pop();
+    k->follow_weak_klass_links(&is_alive, &keep_alive);
   }
   follow_stack();
 }
 
 void MarkSweep::revisit_mdo(DataLayout* p) {
-  _revisit_mdo_stack->push(p);
+  _revisit_mdo_stack.push(p);
 }
 
 void MarkSweep::follow_mdo_weak_refs() {
   // All strongly reachable oops have been marked at this point;
   // we can visit and clear any weak references from MDO's which
   // we memoized during the strong marking phase.
-  assert(_marking_stack->is_empty(), "Marking stack should be empty");
+  assert(_marking_stack.is_empty(), "Marking stack should be empty");
   if (PrintRevisitStats) {
-    gclog_or_tty->print_cr("#classes in system dictionary = %d", SystemDictionary::number_of_classes());
-    gclog_or_tty->print_cr("Revisit MDO stack length = %d", _revisit_mdo_stack->length());
+    gclog_or_tty->print_cr("#classes in system dictionary = %d",
+                           SystemDictionary::number_of_classes());
+    gclog_or_tty->print_cr("Revisit MDO stack size = " SIZE_FORMAT,
+                           _revisit_mdo_stack.size());
   }
-  for (int i = 0; i < _revisit_mdo_stack->length(); i++) {
-    _revisit_mdo_stack->at(i)->follow_weak_refs(&is_alive);
+  while (!_revisit_mdo_stack.is_empty()) {
+    _revisit_mdo_stack.pop()->follow_weak_refs(&is_alive);
   }
   follow_stack();
 }
@@ -106,41 +111,37 @@
 
 void MarkSweep::follow_stack() {
   do {
-    while (!_marking_stack->is_empty()) {
-      oop obj = _marking_stack->pop();
+    while (!_marking_stack.is_empty()) {
+      oop obj = _marking_stack.pop();
       assert (obj->is_gc_marked(), "p must be marked");
       obj->follow_contents();
     }
     // Process ObjArrays one at a time to avoid marking stack bloat.
-    if (!_objarray_stack->is_empty()) {
-      ObjArrayTask task = _objarray_stack->pop();
+    if (!_objarray_stack.is_empty()) {
+      ObjArrayTask task = _objarray_stack.pop();
       objArrayKlass* const k = (objArrayKlass*)task.obj()->blueprint();
       k->oop_follow_contents(task.obj(), task.index());
     }
-  } while (!_marking_stack->is_empty() || !_objarray_stack->is_empty());
+  } while (!_marking_stack.is_empty() || !_objarray_stack.is_empty());
 }
 
 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
 
 void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }
 
-// We preserve the mark which should be replaced at the end and the location that it
-// will go.  Note that the object that this markOop belongs to isn't currently at that
-// address but it will be after phase4
+// We preserve the mark which should be replaced at the end and the location
+// that it will go.  Note that the object that this markOop belongs to isn't
+// currently at that address but it will be after phase4
 void MarkSweep::preserve_mark(oop obj, markOop mark) {
-  // we try to store preserved marks in the to space of the new generation since this
-  // is storage which should be available.  Most of the time this should be sufficient
-  // space for the marks we need to preserve but if it isn't we fall back in using
-  // GrowableArrays to keep track of the overflow.
+  // We try to store preserved marks in the to space of the new generation since
+  // this is storage which should be available.  Most of the time this should be
+  // sufficient space for the marks we need to preserve but if it isn't we fall
+  // back to using Stacks to keep track of the overflow.
   if (_preserved_count < _preserved_count_max) {
     _preserved_marks[_preserved_count++].init(obj, mark);
   } else {
-    if (_preserved_mark_stack == NULL) {
-      _preserved_mark_stack = new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true);
-      _preserved_oop_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true);
-    }
-    _preserved_mark_stack->push(mark);
-    _preserved_oop_stack->push(obj);
+    _preserved_mark_stack.push(mark);
+    _preserved_oop_stack.push(obj);
   }
 }
 
@@ -151,8 +152,7 @@
 void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p, _is_root); }
 
 void MarkSweep::adjust_marks() {
-  assert(_preserved_oop_stack == NULL ||
-         _preserved_oop_stack->length() == _preserved_mark_stack->length(),
+  assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(),
          "inconsistent preserved oop stacks");
 
   // adjust the oops we saved earlier
@@ -161,21 +161,19 @@
   }
 
   // deal with the overflow stack
-  if (_preserved_oop_stack) {
-    for (int i = 0; i < _preserved_oop_stack->length(); i++) {
-      oop* p = _preserved_oop_stack->adr_at(i);
-      adjust_pointer(p);
-    }
+  StackIterator<oop> iter(_preserved_oop_stack);
+  while (!iter.is_empty()) {
+    oop* p = iter.next_addr();
+    adjust_pointer(p);
   }
 }
 
 void MarkSweep::restore_marks() {
-  assert(_preserved_oop_stack == NULL ||
-         _preserved_oop_stack->length() == _preserved_mark_stack->length(),
+  assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(),
          "inconsistent preserved oop stacks");
   if (PrintGC && Verbose) {
-    gclog_or_tty->print_cr("Restoring %d marks", _preserved_count +
-                  (_preserved_oop_stack ? _preserved_oop_stack->length() : 0));
+    gclog_or_tty->print_cr("Restoring %d marks",
+                           _preserved_count + _preserved_oop_stack.size());
   }
 
   // restore the marks we saved earlier
@@ -184,12 +182,10 @@
   }
 
   // deal with the overflow
-  if (_preserved_oop_stack) {
-    for (int i = 0; i < _preserved_oop_stack->length(); i++) {
-      oop obj       = _preserved_oop_stack->at(i);
-      markOop mark  = _preserved_mark_stack->at(i);
-      obj->set_mark(mark);
-    }
+  while (!_preserved_oop_stack.is_empty()) {
+    oop obj       = _preserved_oop_stack.pop();
+    markOop mark  = _preserved_mark_stack.pop();
+    obj->set_mark(mark);
   }
 }