1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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24
25#ifndef SHARE_GC_PARALLEL_MUTABLESPACE_HPP
26#define SHARE_GC_PARALLEL_MUTABLESPACE_HPP
27
28#include "gc/parallel/immutableSpace.hpp"
29#include "memory/memRegion.hpp"
30#include "utilities/copy.hpp"
31
32// A MutableSpace is a subtype of ImmutableSpace that supports the
33// concept of allocation. This includes the concepts that a space may
34// be only partially full, and the query methods that go with such
35// an assumption. MutableSpace is also responsible for minimizing the
36// page allocation time by having the memory pretouched (with
37// AlwaysPretouch) and for optimizing page placement on NUMA systems
38// by make the underlying region interleaved (with UseNUMA).
39//
40// Invariant: (ImmutableSpace +) bottom() <= top() <= end()
41// top() is inclusive and end() is exclusive.
42
43class MutableSpaceMangler;
44
45class MutableSpace: public ImmutableSpace {
46 friend class VMStructs;
47
48 // Helper for mangling unused space in debug builds
49 MutableSpaceMangler* _mangler;
50 // The last region which page had been setup to be interleaved.
51 MemRegion _last_setup_region;
52 size_t _alignment;
53 protected:
54 HeapWord* volatile _top;
55
56 MutableSpaceMangler* mangler() { return _mangler; }
57
58 void numa_setup_pages(MemRegion mr, bool clear_space);
59 void pretouch_pages(MemRegion mr);
60
61 void set_last_setup_region(MemRegion mr) { _last_setup_region = mr; }
62 MemRegion last_setup_region() const { return _last_setup_region; }
63
64 public:
65 virtual ~MutableSpace();
66 MutableSpace(size_t page_size);
67
68 // Accessors
69 HeapWord* top() const { return _top; }
70 virtual void set_top(HeapWord* value) { _top = value; }
71
72 HeapWord* volatile* top_addr() { return &_top; }
73 HeapWord** end_addr() { return &_end; }
74
75 virtual void set_bottom(HeapWord* value) { _bottom = value; }
76 virtual void set_end(HeapWord* value) { _end = value; }
77
78 size_t alignment() { return _alignment; }
79
80 // Returns a subregion containing all objects in this space.
81 MemRegion used_region() { return MemRegion(bottom(), top()); }
82
83 static const bool SetupPages = true;
84 static const bool DontSetupPages = false;
85
86 // Initialization
87 virtual void initialize(MemRegion mr,
88 bool clear_space,
89 bool mangle_space,
90 bool setup_pages = SetupPages);
91
92 virtual void clear(bool mangle_space);
93 // Does the usual initialization but optionally resets top to bottom.
94#if 0 // MANGLE_SPACE
95 void initialize(MemRegion mr, bool clear_space, bool reset_top);
96#endif
97 virtual void update() { }
98 virtual void accumulate_statistics() { }
99
100 // Methods used in mangling. See descriptions under SpaceMangler.
101 virtual void mangle_unused_area() PRODUCT_RETURN;
102 virtual void mangle_unused_area_complete() PRODUCT_RETURN;
103 virtual void check_mangled_unused_area(HeapWord* limit) PRODUCT_RETURN;
104 virtual void check_mangled_unused_area_complete() PRODUCT_RETURN;
105 virtual void set_top_for_allocations(HeapWord* v) PRODUCT_RETURN;
106
107 // Used to save the space's current top for later use during mangling.
108 virtual void set_top_for_allocations() PRODUCT_RETURN;
109
110 virtual void ensure_parsability() { }
111
112 virtual void mangle_region(MemRegion mr) PRODUCT_RETURN;
113
114 // Boolean queries.
115 bool is_empty() const { return used_in_words() == 0; }
116 bool not_empty() const { return used_in_words() > 0; }
117 bool contains(const void* p) const { return _bottom <= p && p < _end; }
118
119 // Size computations. Sizes are in bytes.
120 size_t used_in_bytes() const { return used_in_words() * HeapWordSize; }
121 size_t free_in_bytes() const { return free_in_words() * HeapWordSize; }
122
123 // Size computations. Sizes are in heapwords.
124 virtual size_t used_in_words() const { return pointer_delta(top(), bottom()); }
125 virtual size_t free_in_words() const { return pointer_delta(end(), top()); }
126 virtual size_t tlab_capacity(Thread* thr) const { return capacity_in_bytes(); }
127 virtual size_t tlab_used(Thread* thr) const { return used_in_bytes(); }
128 virtual size_t unsafe_max_tlab_alloc(Thread* thr) const { return free_in_bytes(); }
129
130 // Allocation (return NULL if full)
131 virtual HeapWord* allocate(size_t word_size);
132 virtual HeapWord* cas_allocate(size_t word_size);
133 // Optional deallocation. Used in NUMA-allocator.
134 bool cas_deallocate(HeapWord *obj, size_t size);
135
136 // Iteration.
137 void oop_iterate(OopIterateClosure* cl);
138 void object_iterate(ObjectClosure* cl);
139
140 // Debugging
141 virtual void print() const;
142 virtual void print_on(outputStream* st) const;
143 virtual void print_short() const;
144 virtual void print_short_on(outputStream* st) const;
145 virtual void verify();
146};
147
148#endif // SHARE_GC_PARALLEL_MUTABLESPACE_HPP
149