1 /*
2 * Copyright (c) 2011, 2018, 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.
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23 */
24
25 #ifndef SHARE_VM_GC_G1_HEAPREGIONSET_HPP
26 #define SHARE_VM_GC_G1_HEAPREGIONSET_HPP
27
28 #include "gc/g1/heapRegion.hpp"
29 #include "utilities/macros.hpp"
30
31 #define assert_heap_region_set(p, message) \
32 do { \
33 assert((p), "[%s] %s ln: %u", \
34 name(), message, length()); \
35 } while (0)
36
37 #define guarantee_heap_region_set(p, message) \
38 do { \
39 guarantee((p), "[%s] %s ln: %u", \
40 name(), message, length()); \
41 } while (0)
42
43 #define assert_free_region_list(p, message) \
44 do { \
45 assert((p), "[%s] %s ln: %u hd: " PTR_FORMAT " tl: " PTR_FORMAT, \
46 name(), message, length(), p2i(_head), p2i(_tail)); \
47 } while (0)
48
49
50 class HRSMtSafeChecker : public CHeapObj<mtGC> {
51 public:
52 virtual void check() = 0;
53 };
54
55 class MasterFreeRegionListMtSafeChecker : public HRSMtSafeChecker { public: void check(); };
56 class HumongousRegionSetMtSafeChecker : public HRSMtSafeChecker { public: void check(); };
57 class OldRegionSetMtSafeChecker : public HRSMtSafeChecker { public: void check(); };
58
59 // Base class for all the classes that represent heap region sets. It
60 // contains the basic attributes that each set needs to maintain
61 // (e.g., length, region num, used bytes sum) plus any shared
62 // functionality (e.g., verification).
63
64 class HeapRegionSetBase {
65 friend class VMStructs;
66 private:
67 bool _is_humongous;
68 bool _is_free;
69 HRSMtSafeChecker* _mt_safety_checker;
70
71 protected:
72 // The number of regions in to the set.
73 uint _length;
74
75 const char* _name;
76
77 bool _verify_in_progress;
78
79 // verify_region() is used to ensure that the contents of a region
80 // added to / removed from a set are consistent.
81 void verify_region(HeapRegion* hr) PRODUCT_RETURN;
82
83 // Indicates whether all regions in the set should be humongous or
84 // not. Only used during verification.
85 bool regions_humongous() { return _is_humongous; }
86
87 // Indicates whether all regions in the set should be free or
88 // not. Only used during verification.
89 bool regions_free() { return _is_free; }
90
91 void check_mt_safety() {
92 if (_mt_safety_checker != NULL) {
93 _mt_safety_checker->check();
94 }
95 }
96
97 HeapRegionSetBase(const char* name, bool humongous, bool free, HRSMtSafeChecker* mt_safety_checker);
98
99 public:
100 const char* name() { return _name; }
101
102 uint length() const { return _length; }
103
104 bool is_empty() { return _length == 0; }
105
106 // It updates the fields of the set to reflect hr being added to
107 // the set and tags the region appropriately.
108 inline void add(HeapRegion* hr);
109
110 // It updates the fields of the set to reflect hr being removed
111 // from the set and tags the region appropriately.
112 inline void remove(HeapRegion* hr);
113
114 virtual void verify();
115 void verify_start();
116 void verify_next_region(HeapRegion* hr);
117 void verify_end();
118
119 void verify_optional() { DEBUG_ONLY(verify();) }
120
121 virtual void print_on(outputStream* out, bool print_contents = false);
122 };
123
124 #define hrs_assert_sets_match(_set1_, _set2_) \
125 do { \
126 assert(((_set1_)->regions_humongous() == (_set2_)->regions_humongous()) && \
127 ((_set1_)->regions_free() == (_set2_)->regions_free()), \
128 "the contents of set %s and set %s should match", \
129 (_set1_)->name(), \
130 (_set2_)->name()); \
131 } while (0)
132
133 // This class represents heap region sets whose members are not
134 // explicitly tracked. It's helpful to group regions using such sets
135 // so that we can reason about all the region groups in the heap using
136 // the same interface (namely, the HeapRegionSetBase API).
137
138 class HeapRegionSet : public HeapRegionSetBase {
139 public:
140 HeapRegionSet(const char* name, bool humongous, HRSMtSafeChecker* mt_safety_checker):
141 HeapRegionSetBase(name, humongous, false /* free */, mt_safety_checker) { }
142
143 void bulk_remove(const uint removed) {
144 _length -= removed;
145 }
146 };
147
148 // A set that links all the regions added to it in a doubly-linked
149 // sorted list. We should try to avoid doing operations that iterate over
150 // such lists in performance critical paths. Typically we should
151 // add / remove one region at a time or concatenate two lists.
152
153 class FreeRegionListIterator;
154
155 class FreeRegionList : public HeapRegionSetBase {
156 friend class FreeRegionListIterator;
157
158 private:
159 HeapRegion* _head;
160 HeapRegion* _tail;
161
162 // _last is used to keep track of where we added an element the last
163 // time. It helps to improve performance when adding several ordered items in a row.
164 HeapRegion* _last;
165
166 static uint _unrealistically_long_length;
167
168 inline HeapRegion* remove_from_head_impl();
169 inline HeapRegion* remove_from_tail_impl();
170
171 protected:
172 // See the comment for HeapRegionSetBase::clear()
173 virtual void clear();
174
175 public:
176 FreeRegionList(const char* name, HRSMtSafeChecker* mt_safety_checker = NULL):
177 HeapRegionSetBase(name, false /* humongous */, true /* empty */, mt_safety_checker) {
178 clear();
179 }
180
181 void verify_list();
182
183 #ifdef ASSERT
184 bool contains(HeapRegion* hr) const {
185 return hr->containing_set() == this;
186 }
187 #endif
188
189 static void set_unrealistically_long_length(uint len);
190
191 // Add hr to the list. The region should not be a member of another set.
192 // Assumes that the list is ordered and will preserve that order. The order
193 // is determined by hrm_index.
194 inline void add_ordered(HeapRegion* hr);
195 inline HeapRegion* show_tail() { return _tail; }
196 // Removes from head or tail based on the given argument.
197 HeapRegion* remove_region(bool from_head);
198
199 // Merge two ordered lists. The result is also ordered. The order is
200 // determined by hrm_index.
201 void add_ordered(FreeRegionList* from_list);
202
203 // It empties the list by removing all regions from it.
204 void remove_all();
205
206 // Remove all (contiguous) regions from first to first + num_regions -1 from
207 // this list.
208 // Num_regions must be > 1.
209 void remove_starting_at(HeapRegion* first, uint num_regions);
210
211 virtual void verify();
212 };
213
214 // Iterator class that provides a convenient way to iterate over the
215 // regions of a FreeRegionList.
216
217 class FreeRegionListIterator : public StackObj {
218 private:
219 FreeRegionList* _list;
220 HeapRegion* _curr;
221
222 public:
223 bool more_available() {
224 return _curr != NULL;
225 }
226
227 HeapRegion* get_next() {
228 assert(more_available(),
229 "get_next() should be called when more regions are available");
230
231 // If we are going to introduce a count in the iterator we should
232 // do the "cycle" check.
233
234 HeapRegion* hr = _curr;
235 _list->verify_region(hr);
236 _curr = hr->next();
237 return hr;
238 }
239
240 FreeRegionListIterator(FreeRegionList* list) : _curr(NULL), _list(list) {
241 _curr = list->_head;
242 }
243 };
244
245 #endif // SHARE_VM_GC_G1_HEAPREGIONSET_HPP