hotspot/src/share/vm/gc_implementation/shared/mutableSpace.hpp
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rev 611 : Merge
@@ -1,10 +1,10 @@
#ifdef USE_PRAGMA_IDENT_HDR
#pragma ident "@(#)mutableSpace.hpp 1.22 07/05/05 17:05:35 JVM"
#endif
/*
- * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2008 Sun Microsystems, Inc. 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
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
@@ -31,18 +31,27 @@
// an assumption.
//
// Invariant: (ImmutableSpace +) bottom() <= top() <= end()
// top() is inclusive and end() is exclusive.
+class MutableSpaceMangler;
+
class MutableSpace: public ImmutableSpace {
friend class VMStructs;
+
+ // Helper for mangling unused space in debug builds
+ MutableSpaceMangler* _mangler;
+
protected:
HeapWord* _top;
+ MutableSpaceMangler* mangler() { return _mangler; }
+
public:
- virtual ~MutableSpace() {}
- MutableSpace() { _top = NULL; }
+ virtual ~MutableSpace();
+ MutableSpace();
+
// Accessors
HeapWord* top() const { return _top; }
virtual void set_top(HeapWord* value) { _top = value; }
HeapWord** top_addr() { return &_top; }
@@ -53,25 +62,34 @@
// Returns a subregion containing all objects in this space.
MemRegion used_region() { return MemRegion(bottom(), top()); }
// Initialization
- virtual void initialize(MemRegion mr, bool clear_space);
- virtual void clear();
+ virtual void initialize(MemRegion mr,
+ bool clear_space,
+ bool mangle_space);
+ virtual void clear(bool mangle_space);
+ // Does the usual initialization but optionally resets top to bottom.
+#if 0 // MANGLE_SPACE
+ void initialize(MemRegion mr, bool clear_space, bool reset_top);
+#endif
virtual void update() { }
virtual void accumulate_statistics() { }
- // Overwrites the unused portion of this space. Note that some collectors
- // may use this "scratch" space during collections.
- virtual void mangle_unused_area() {
- mangle_region(MemRegion(_top, _end));
- }
+ // Methods used in mangling. See descriptions under SpaceMangler.
+ virtual void mangle_unused_area() PRODUCT_RETURN;
+ virtual void mangle_unused_area_complete() PRODUCT_RETURN;
+ virtual void check_mangled_unused_area(HeapWord* limit) PRODUCT_RETURN;
+ virtual void check_mangled_unused_area_complete() PRODUCT_RETURN;
+ virtual void set_top_for_allocations(HeapWord* v) PRODUCT_RETURN;
+
+ // Used to save the space's current top for later use during mangling.
+ virtual void set_top_for_allocations() PRODUCT_RETURN;
+
virtual void ensure_parsability() { }
- void mangle_region(MemRegion mr) {
- debug_only(Copy::fill_to_words(mr.start(), mr.word_size(), badHeapWord));
- }
+ virtual void mangle_region(MemRegion mr) PRODUCT_RETURN;
// Boolean querries.
bool is_empty() const { return used_in_words() == 0; }
bool not_empty() const { return used_in_words() > 0; }
bool contains(const void* p) const { return _bottom <= p && p < _end; }
@@ -99,7 +117,7 @@
// Debugging
virtual void print() const;
virtual void print_on(outputStream* st) const;
virtual void print_short() const;
virtual void print_short_on(outputStream* st) const;
- virtual void verify(bool allow_dirty) const;
+ virtual void verify(bool allow_dirty);
};