1 /* 2 * Copyright (c) 2001, 2021, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_GC_PARALLEL_MUTABLESPACE_HPP 26 #define SHARE_GC_PARALLEL_MUTABLESPACE_HPP 27 28 #include "memory/allocation.hpp" 29 #include "memory/iterator.hpp" 30 #include "memory/memRegion.hpp" 31 #include "utilities/copy.hpp" 32 #include "utilities/globalDefinitions.hpp" 33 #include "utilities/macros.hpp" 34 35 class WorkGang; 36 37 // A MutableSpace supports the concept of allocation. This includes the 38 // concepts that a space may be only partially full, and the query methods 39 // that go with such an assumption. 40 // 41 // MutableSpace is also responsible for minimizing the 42 // page allocation time by having the memory pretouched (with 43 // AlwaysPretouch) and for optimizing page placement on NUMA systems 44 // by make the underlying region interleaved (with UseNUMA). 45 // 46 // Invariant: bottom() <= top() <= end() 47 // top() and end() are exclusive. 48 49 class MutableSpaceMangler; 50 51 class MutableSpace: public CHeapObj<mtGC> { 52 friend class VMStructs; 53 54 // Helper for mangling unused space in debug builds 55 MutableSpaceMangler* _mangler; 56 // The last region which page had been setup to be interleaved. 57 MemRegion _last_setup_region; 58 size_t _alignment; 59 HeapWord* _bottom; 60 HeapWord* volatile _top; 61 HeapWord* _end; 62 63 MutableSpaceMangler* mangler() { return _mangler; } 64 65 void numa_setup_pages(MemRegion mr, bool clear_space); 66 67 void set_last_setup_region(MemRegion mr) { _last_setup_region = mr; } 68 MemRegion last_setup_region() const { return _last_setup_region; } 69 70 public: 71 virtual ~MutableSpace(); 72 MutableSpace(size_t page_size); 73 74 // Accessors 75 HeapWord* bottom() const { return _bottom; } 76 HeapWord* top() const { return _top; } 77 HeapWord* end() const { return _end; } 78 79 void set_bottom(HeapWord* value) { _bottom = value; } 80 virtual void set_top(HeapWord* value) { _top = value; } 81 void set_end(HeapWord* value) { _end = value; } 82 83 HeapWord* volatile* top_addr() { return &_top; } 84 HeapWord** end_addr() { return &_end; } 85 86 size_t alignment() { return _alignment; } 87 88 MemRegion region() const { return MemRegion(bottom(), end()); } 89 90 size_t capacity_in_bytes() const { return capacity_in_words() * HeapWordSize; } 91 size_t capacity_in_words() const { return pointer_delta(end(), bottom()); } 92 virtual size_t capacity_in_words(Thread*) const { return capacity_in_words(); } 93 94 // Returns a subregion containing all objects in this space. 95 MemRegion used_region() { return MemRegion(bottom(), top()); } 96 97 static const bool SetupPages = true; 98 static const bool DontSetupPages = false; 99 100 // Initialization 101 virtual void initialize(MemRegion mr, 102 bool clear_space, 103 bool mangle_space, 104 bool setup_pages = SetupPages, 105 WorkGang* pretouch_gang = NULL); 106 107 virtual void clear(bool mangle_space); 108 virtual void update() { } 109 virtual void accumulate_statistics() { } 110 111 // Methods used in mangling. See descriptions under SpaceMangler. 112 virtual void mangle_unused_area() PRODUCT_RETURN; 113 virtual void mangle_unused_area_complete() PRODUCT_RETURN; 114 virtual void check_mangled_unused_area(HeapWord* limit) PRODUCT_RETURN; 115 virtual void check_mangled_unused_area_complete() PRODUCT_RETURN; 116 virtual void set_top_for_allocations(HeapWord* v) PRODUCT_RETURN; 117 118 // Used to save the space's current top for later use during mangling. 119 virtual void set_top_for_allocations() PRODUCT_RETURN; 120 121 virtual void ensure_parsability() { } 122 123 virtual void mangle_region(MemRegion mr) PRODUCT_RETURN; 124 125 // Boolean queries. 126 bool is_empty() const { return used_in_words() == 0; } 127 bool not_empty() const { return used_in_words() > 0; } 128 bool contains(const void* p) const { return _bottom <= p && p < _end; } 129 130 // Size computations. Sizes are in bytes. 131 size_t used_in_bytes() const { return used_in_words() * HeapWordSize; } 132 size_t free_in_bytes() const { return free_in_words() * HeapWordSize; } 133 134 // Size computations. Sizes are in heapwords. 135 virtual size_t used_in_words() const { return pointer_delta(top(), bottom()); } 136 virtual size_t free_in_words() const { return pointer_delta(end(), top()); } 137 virtual size_t tlab_capacity(Thread* thr) const { return capacity_in_bytes(); } 138 virtual size_t tlab_used(Thread* thr) const { return used_in_bytes(); } 139 virtual size_t unsafe_max_tlab_alloc(Thread* thr) const { return free_in_bytes(); } 140 141 // Allocation (return NULL if full) 142 virtual HeapWord* cas_allocate(size_t word_size); 143 // Optional deallocation. Used in NUMA-allocator. 144 bool cas_deallocate(HeapWord *obj, size_t size); 145 // Return true if this space needs to be expanded in order to satisfy an 146 // allocation request of the indicated size. Concurrent allocations and 147 // resizes may change the result of a later call. Used by oldgen allocator. 148 // precondition: holding ExpandHeap_lock 149 bool needs_expand(size_t word_size) const; 150 151 // Iteration. 152 void oop_iterate(OopIterateClosure* cl); 153 void object_iterate(ObjectClosure* cl); 154 155 // Debugging 156 virtual void print() const; 157 virtual void print_on(outputStream* st) const; 158 virtual void print_short() const; 159 virtual void print_short_on(outputStream* st) const; 160 virtual void verify(); 161 }; 162 163 #endif // SHARE_GC_PARALLEL_MUTABLESPACE_HPP --- EOF ---