1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/shared/mutableSpace.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,102 @@
1.4 +/*
1.5 + * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +// A MutableSpace is a subtype of ImmutableSpace that supports the
1.29 +// concept of allocation. This includes the concepts that a space may
1.30 +// be only partially full, and the querry methods that go with such
1.31 +// an assumption.
1.32 +//
1.33 +// Invariant: (ImmutableSpace +) bottom() <= top() <= end()
1.34 +// top() is inclusive and end() is exclusive.
1.35 +
1.36 +class MutableSpace: public ImmutableSpace {
1.37 + friend class VMStructs;
1.38 + protected:
1.39 + HeapWord* _top;
1.40 +
1.41 + public:
1.42 + virtual ~MutableSpace() {}
1.43 + MutableSpace() { _top = NULL; }
1.44 + // Accessors
1.45 + HeapWord* top() const { return _top; }
1.46 + virtual void set_top(HeapWord* value) { _top = value; }
1.47 +
1.48 + HeapWord** top_addr() { return &_top; }
1.49 + HeapWord** end_addr() { return &_end; }
1.50 +
1.51 + virtual void set_bottom(HeapWord* value) { _bottom = value; }
1.52 + virtual void set_end(HeapWord* value) { _end = value; }
1.53 +
1.54 + // Returns a subregion containing all objects in this space.
1.55 + MemRegion used_region() { return MemRegion(bottom(), top()); }
1.56 +
1.57 + // Initialization
1.58 + virtual void initialize(MemRegion mr, bool clear_space);
1.59 + virtual void clear();
1.60 + virtual void update() { }
1.61 + virtual void accumulate_statistics() { }
1.62 +
1.63 + // Overwrites the unused portion of this space. Note that some collectors
1.64 + // may use this "scratch" space during collections.
1.65 + virtual void mangle_unused_area() {
1.66 + mangle_region(MemRegion(_top, _end));
1.67 + }
1.68 + virtual void ensure_parsability() { }
1.69 +
1.70 + void mangle_region(MemRegion mr) {
1.71 + debug_only(Copy::fill_to_words(mr.start(), mr.word_size(), badHeapWord));
1.72 + }
1.73 +
1.74 + // Boolean querries.
1.75 + bool is_empty() const { return used_in_words() == 0; }
1.76 + bool not_empty() const { return used_in_words() > 0; }
1.77 + bool contains(const void* p) const { return _bottom <= p && p < _end; }
1.78 +
1.79 + // Size computations. Sizes are in bytes.
1.80 + size_t used_in_bytes() const { return used_in_words() * HeapWordSize; }
1.81 + size_t free_in_bytes() const { return free_in_words() * HeapWordSize; }
1.82 +
1.83 + // Size computations. Sizes are in heapwords.
1.84 + virtual size_t used_in_words() const { return pointer_delta(top(), bottom()); }
1.85 + virtual size_t free_in_words() const { return pointer_delta(end(), top()); }
1.86 + virtual size_t tlab_capacity(Thread* thr) const { return capacity_in_bytes(); }
1.87 + virtual size_t unsafe_max_tlab_alloc(Thread* thr) const { return free_in_bytes(); }
1.88 +
1.89 + // Allocation (return NULL if full)
1.90 + virtual HeapWord* allocate(size_t word_size);
1.91 + virtual HeapWord* cas_allocate(size_t word_size);
1.92 + // Optional deallocation. Used in NUMA-allocator.
1.93 + bool cas_deallocate(HeapWord *obj, size_t size);
1.94 +
1.95 + // Iteration.
1.96 + void oop_iterate(OopClosure* cl);
1.97 + void object_iterate(ObjectClosure* cl);
1.98 +
1.99 + // Debugging
1.100 + virtual void print() const;
1.101 + virtual void print_on(outputStream* st) const;
1.102 + virtual void print_short() const;
1.103 + virtual void print_short_on(outputStream* st) const;
1.104 + virtual void verify(bool allow_dirty) const;
1.105 +};
