Thu, 05 Jun 2008 15:57:56 -0700
6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
duke@435 | 1 | /* |
duke@435 | 2 | * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | // A MutableSpace is a subtype of ImmutableSpace that supports the |
duke@435 | 26 | // concept of allocation. This includes the concepts that a space may |
duke@435 | 27 | // be only partially full, and the querry methods that go with such |
duke@435 | 28 | // an assumption. |
duke@435 | 29 | // |
duke@435 | 30 | // Invariant: (ImmutableSpace +) bottom() <= top() <= end() |
duke@435 | 31 | // top() is inclusive and end() is exclusive. |
duke@435 | 32 | |
duke@435 | 33 | class MutableSpace: public ImmutableSpace { |
duke@435 | 34 | friend class VMStructs; |
duke@435 | 35 | protected: |
duke@435 | 36 | HeapWord* _top; |
duke@435 | 37 | |
duke@435 | 38 | public: |
duke@435 | 39 | virtual ~MutableSpace() {} |
duke@435 | 40 | MutableSpace() { _top = NULL; } |
duke@435 | 41 | // Accessors |
duke@435 | 42 | HeapWord* top() const { return _top; } |
duke@435 | 43 | virtual void set_top(HeapWord* value) { _top = value; } |
duke@435 | 44 | |
duke@435 | 45 | HeapWord** top_addr() { return &_top; } |
duke@435 | 46 | HeapWord** end_addr() { return &_end; } |
duke@435 | 47 | |
duke@435 | 48 | virtual void set_bottom(HeapWord* value) { _bottom = value; } |
duke@435 | 49 | virtual void set_end(HeapWord* value) { _end = value; } |
duke@435 | 50 | |
duke@435 | 51 | // Returns a subregion containing all objects in this space. |
duke@435 | 52 | MemRegion used_region() { return MemRegion(bottom(), top()); } |
duke@435 | 53 | |
duke@435 | 54 | // Initialization |
duke@435 | 55 | virtual void initialize(MemRegion mr, bool clear_space); |
duke@435 | 56 | virtual void clear(); |
duke@435 | 57 | virtual void update() { } |
duke@435 | 58 | virtual void accumulate_statistics() { } |
duke@435 | 59 | |
duke@435 | 60 | // Overwrites the unused portion of this space. Note that some collectors |
duke@435 | 61 | // may use this "scratch" space during collections. |
duke@435 | 62 | virtual void mangle_unused_area() { |
duke@435 | 63 | mangle_region(MemRegion(_top, _end)); |
duke@435 | 64 | } |
duke@435 | 65 | virtual void ensure_parsability() { } |
duke@435 | 66 | |
duke@435 | 67 | void mangle_region(MemRegion mr) { |
duke@435 | 68 | debug_only(Copy::fill_to_words(mr.start(), mr.word_size(), badHeapWord)); |
duke@435 | 69 | } |
duke@435 | 70 | |
duke@435 | 71 | // Boolean querries. |
duke@435 | 72 | bool is_empty() const { return used_in_words() == 0; } |
duke@435 | 73 | bool not_empty() const { return used_in_words() > 0; } |
duke@435 | 74 | bool contains(const void* p) const { return _bottom <= p && p < _end; } |
duke@435 | 75 | |
duke@435 | 76 | // Size computations. Sizes are in bytes. |
duke@435 | 77 | size_t used_in_bytes() const { return used_in_words() * HeapWordSize; } |
duke@435 | 78 | size_t free_in_bytes() const { return free_in_words() * HeapWordSize; } |
duke@435 | 79 | |
duke@435 | 80 | // Size computations. Sizes are in heapwords. |
duke@435 | 81 | virtual size_t used_in_words() const { return pointer_delta(top(), bottom()); } |
duke@435 | 82 | virtual size_t free_in_words() const { return pointer_delta(end(), top()); } |
duke@435 | 83 | virtual size_t tlab_capacity(Thread* thr) const { return capacity_in_bytes(); } |
duke@435 | 84 | virtual size_t unsafe_max_tlab_alloc(Thread* thr) const { return free_in_bytes(); } |
duke@435 | 85 | |
duke@435 | 86 | // Allocation (return NULL if full) |
duke@435 | 87 | virtual HeapWord* allocate(size_t word_size); |
duke@435 | 88 | virtual HeapWord* cas_allocate(size_t word_size); |
duke@435 | 89 | // Optional deallocation. Used in NUMA-allocator. |
duke@435 | 90 | bool cas_deallocate(HeapWord *obj, size_t size); |
duke@435 | 91 | |
duke@435 | 92 | // Iteration. |
duke@435 | 93 | void oop_iterate(OopClosure* cl); |
duke@435 | 94 | void object_iterate(ObjectClosure* cl); |
duke@435 | 95 | |
duke@435 | 96 | // Debugging |
duke@435 | 97 | virtual void print() const; |
duke@435 | 98 | virtual void print_on(outputStream* st) const; |
duke@435 | 99 | virtual void print_short() const; |
duke@435 | 100 | virtual void print_short_on(outputStream* st) const; |
duke@435 | 101 | virtual void verify(bool allow_dirty) const; |
duke@435 | 102 | }; |