Mercurial > hg > truffle
diff src/share/vm/gc_implementation/shared/mutableSpace.hpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | d1635bf93939 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/shared/mutableSpace.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,102 @@ +/* + * Copyright 2001-2007 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. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +// A MutableSpace is a subtype of ImmutableSpace that supports the +// concept of allocation. This includes the concepts that a space may +// be only partially full, and the querry methods that go with such +// an assumption. +// +// Invariant: (ImmutableSpace +) bottom() <= top() <= end() +// top() is inclusive and end() is exclusive. + +class MutableSpace: public ImmutableSpace { + friend class VMStructs; + protected: + HeapWord* _top; + + public: + virtual ~MutableSpace() {} + MutableSpace() { _top = NULL; } + // Accessors + HeapWord* top() const { return _top; } + virtual void set_top(HeapWord* value) { _top = value; } + + HeapWord** top_addr() { return &_top; } + HeapWord** end_addr() { return &_end; } + + virtual void set_bottom(HeapWord* value) { _bottom = value; } + virtual void set_end(HeapWord* value) { _end = value; } + + // 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 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)); + } + virtual void ensure_parsability() { } + + void mangle_region(MemRegion mr) { + debug_only(Copy::fill_to_words(mr.start(), mr.word_size(), badHeapWord)); + } + + // 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; } + + // Size computations. Sizes are in bytes. + size_t used_in_bytes() const { return used_in_words() * HeapWordSize; } + size_t free_in_bytes() const { return free_in_words() * HeapWordSize; } + + // Size computations. Sizes are in heapwords. + virtual size_t used_in_words() const { return pointer_delta(top(), bottom()); } + virtual size_t free_in_words() const { return pointer_delta(end(), top()); } + virtual size_t tlab_capacity(Thread* thr) const { return capacity_in_bytes(); } + virtual size_t unsafe_max_tlab_alloc(Thread* thr) const { return free_in_bytes(); } + + // Allocation (return NULL if full) + virtual HeapWord* allocate(size_t word_size); + virtual HeapWord* cas_allocate(size_t word_size); + // Optional deallocation. Used in NUMA-allocator. + bool cas_deallocate(HeapWord *obj, size_t size); + + // Iteration. + void oop_iterate(OopClosure* cl); + void object_iterate(ObjectClosure* cl); + + // 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; +};