1 /*
2 * Copyright (c) 2011, 2015, 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_VM_GC_G1_HEAPREGIONSET_HPP
26 #define SHARE_VM_GC_G1_HEAPREGIONSET_HPP
27
28 #include "gc/g1/heapRegion.hpp"
29
30 #define assert_heap_region_set(p, message) \
31 do { \
32 assert((p), "[%s] %s ln: %u", \
33 name(), message, length()); \
34 } while (0)
35
36 #define guarantee_heap_region_set(p, message) \
37 do { \
38 guarantee((p), "[%s] %s ln: %u", \
39 name(), message, length()); \
40 } while (0)
41
42 #define assert_free_region_list(p, message) \
43 do { \
44 assert((p), "[%s] %s ln: %u hd: " PTR_FORMAT " tl: " PTR_FORMAT, \
45 name(), message, length(), p2i(_head), p2i(_tail)); \
46 } while (0)
47
48
49 // Set verification will be forced either if someone defines
50 // HEAP_REGION_SET_FORCE_VERIFY to be 1, or in builds in which
51 // asserts are compiled in.
52 #ifndef HEAP_REGION_SET_FORCE_VERIFY
53 #define HEAP_REGION_SET_FORCE_VERIFY defined(ASSERT)
54 #endif // HEAP_REGION_SET_FORCE_VERIFY
55
56 class HRSMtSafeChecker : public CHeapObj<mtGC> {
57 public:
58 virtual void check() = 0;
59 };
60
61 class MasterFreeRegionListMtSafeChecker : public HRSMtSafeChecker { public: void check(); };
62 class SecondaryFreeRegionListMtSafeChecker : public HRSMtSafeChecker { public: void check(); };
63 class HumongousRegionSetMtSafeChecker : public HRSMtSafeChecker { public: void check(); };
64 class OldRegionSetMtSafeChecker : public HRSMtSafeChecker { public: void check(); };
65
66 // Base class for all the classes that represent heap region sets. It
67 // contains the basic attributes that each set needs to maintain
68 // (e.g., length, region num, used bytes sum) plus any shared
69 // functionality (e.g., verification).
70
71 class HeapRegionSetBase VALUE_OBJ_CLASS_SPEC {
72 friend class VMStructs;
73 private:
74 bool _is_humongous;
75 bool _is_free;
76 HRSMtSafeChecker* _mt_safety_checker;
77
78 protected:
79 // The number of regions in to the set.
80 uint _length;
81
82 const char* _name;
83
84 bool _verify_in_progress;
85
86 // verify_region() is used to ensure that the contents of a region
87 // added to / removed from a set are consistent.
88 void verify_region(HeapRegion* hr) PRODUCT_RETURN;
89
90 // Indicates whether all regions in the set should be humongous or
91 // not. Only used during verification.
92 bool regions_humongous() { return _is_humongous; }
93
94 // Indicates whether all regions in the set should be free or
95 // not. Only used during verification.
96 bool regions_free() { return _is_free; }
97
98 void check_mt_safety() {
99 if (_mt_safety_checker != NULL) {
100 _mt_safety_checker->check();
101 }
102 }
103
104 HeapRegionSetBase(const char* name, bool humongous, bool free, HRSMtSafeChecker* mt_safety_checker);
105
106 public:
107 const char* name() { return _name; }
108
109 uint length() const { return _length; }
110
111 bool is_empty() { return _length == 0; }
112
113 // It updates the fields of the set to reflect hr being added to
114 // the set and tags the region appropriately.
115 inline void add(HeapRegion* hr);
116
117 // It updates the fields of the set to reflect hr being removed
118 // from the set and tags the region appropriately.
119 inline void remove(HeapRegion* hr);
120
121 virtual void verify();
122 void verify_start();
123 void verify_next_region(HeapRegion* hr);
124 void verify_end();
125
126 #if HEAP_REGION_SET_FORCE_VERIFY
127 void verify_optional() {
128 verify();
129 }
130 #else // HEAP_REGION_SET_FORCE_VERIFY
131 void verify_optional() { }
132 #endif // HEAP_REGION_SET_FORCE_VERIFY
133
134 virtual void print_on(outputStream* out, bool print_contents = false);
135 };
136
137 #define hrs_assert_sets_match(_set1_, _set2_) \
138 do { \
139 assert(((_set1_)->regions_humongous() == (_set2_)->regions_humongous()) && \
140 ((_set1_)->regions_free() == (_set2_)->regions_free()), \
141 "the contents of set %s and set %s should match", \
142 (_set1_)->name(), \
143 (_set2_)->name()); \
144 } while (0)
145
146 // This class represents heap region sets whose members are not
147 // explicitly tracked. It's helpful to group regions using such sets
148 // so that we can reason about all the region groups in the heap using
149 // the same interface (namely, the HeapRegionSetBase API).
150
151 class HeapRegionSet : public HeapRegionSetBase {
152 public:
153 HeapRegionSet(const char* name, bool humongous, HRSMtSafeChecker* mt_safety_checker):
154 HeapRegionSetBase(name, humongous, false /* free */, mt_safety_checker) { }
155
156 void bulk_remove(const uint removed) {
157 _length -= removed;
158 }
159 };
160
161 // A set that links all the regions added to it in a doubly-linked
162 // sorted list. We should try to avoid doing operations that iterate over
163 // such lists in performance critical paths. Typically we should
164 // add / remove one region at a time or concatenate two lists.
165
166 class FreeRegionListIterator;
167
168 class FreeRegionList : public HeapRegionSetBase {
169 friend class FreeRegionListIterator;
170
171 private:
172 HeapRegion* _head;
173 HeapRegion* _tail;
174
175 // _last is used to keep track of where we added an element the last
176 // time. It helps to improve performance when adding several ordered items in a row.
177 HeapRegion* _last;
178
179 static uint _unrealistically_long_length;
180
181 inline HeapRegion* remove_from_head_impl();
182 inline HeapRegion* remove_from_tail_impl();
183
184 protected:
185 // See the comment for HeapRegionSetBase::clear()
186 virtual void clear();
187
188 public:
189 FreeRegionList(const char* name, HRSMtSafeChecker* mt_safety_checker = NULL):
190 HeapRegionSetBase(name, false /* humongous */, true /* empty */, mt_safety_checker) {
191 clear();
192 }
193
194 void verify_list();
195
196 #ifdef ASSERT
197 bool contains(HeapRegion* hr) const {
198 return hr->containing_set() == this;
199 }
200 #endif
201
202 static void set_unrealistically_long_length(uint len);
203
204 // Add hr to the list. The region should not be a member of another set.
205 // Assumes that the list is ordered and will preserve that order. The order
206 // is determined by hrm_index.
207 inline void add_ordered(HeapRegion* hr);
208
209 // Removes from head or tail based on the given argument.
210 HeapRegion* remove_region(bool from_head);
211
212 // Merge two ordered lists. The result is also ordered. The order is
213 // determined by hrm_index.
214 void add_ordered(FreeRegionList* from_list);
215
216 // It empties the list by removing all regions from it.
217 void remove_all();
218
219 // Remove all (contiguous) regions from first to first + num_regions -1 from
220 // this list.
221 // Num_regions must be > 1.
222 void remove_starting_at(HeapRegion* first, uint num_regions);
223
224 virtual void verify();
225 };
226
227 // Iterator class that provides a convenient way to iterate over the
228 // regions of a FreeRegionList.
229
230 class FreeRegionListIterator : public StackObj {
231 private:
232 FreeRegionList* _list;
233 HeapRegion* _curr;
234
235 public:
236 bool more_available() {
237 return _curr != NULL;
238 }
239
240 HeapRegion* get_next() {
241 assert(more_available(),
242 "get_next() should be called when more regions are available");
243
244 // If we are going to introduce a count in the iterator we should
245 // do the "cycle" check.
246
247 HeapRegion* hr = _curr;
248 _list->verify_region(hr);
249 _curr = hr->next();
250 return hr;
251 }
252
253 FreeRegionListIterator(FreeRegionList* list) : _curr(NULL), _list(list) {
254 _curr = list->_head;
255 }
256 };
257
258 #endif // SHARE_VM_GC_G1_HEAPREGIONSET_HPP