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annotate src/share/vm/gc_implementation/g1/heapRegionSet.hpp @ 2432:455328d90876
7029458: G1: Add newly-reclaimed regions to the beginning of the region free list, not the end
Summary: What the synopsis says.
Reviewed-by: jwilhelm, iveresov, johnc
| author | tonyp |
|---|---|
| date | Tue, 29 Mar 2011 22:36:16 -0400 |
| parents | 1216415d8e35 |
| children | fe189d4a44e9 |
| rev | line source |
|---|---|
| 2152 | 1 /* |
| 2 * copyright (c) 2011, 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_IMPLEMENTATION_G1_HEAPREGIONSET_HPP | |
| 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSET_HPP | |
| 27 | |
| 28 #include "gc_implementation/g1/heapRegion.hpp" | |
| 29 | |
| 30 // Large buffer for some cases where the output might be larger than normal. | |
| 2361 | 31 #define HRS_ERR_MSG_BUFSZ 512 |
| 32 typedef FormatBuffer<HRS_ERR_MSG_BUFSZ> hrs_err_msg; | |
| 2152 | 33 |
| 34 // Set verification will be forced either if someone defines | |
| 35 // HEAP_REGION_SET_FORCE_VERIFY to be 1, or in builds in which | |
| 36 // asserts are compiled in. | |
| 37 #ifndef HEAP_REGION_SET_FORCE_VERIFY | |
| 38 #define HEAP_REGION_SET_FORCE_VERIFY defined(ASSERT) | |
| 39 #endif // HEAP_REGION_SET_FORCE_VERIFY | |
| 40 | |
| 41 //////////////////// HeapRegionSetBase //////////////////// | |
| 42 | |
| 43 // Base class for all the classes that represent heap region sets. It | |
| 44 // contains the basic attributes that each set needs to maintain | |
| 45 // (e.g., length, region num, used bytes sum) plus any shared | |
| 46 // functionality (e.g., verification). | |
| 47 | |
| 2361 | 48 class hrs_ext_msg; |
| 2152 | 49 |
| 50 class HeapRegionSetBase VALUE_OBJ_CLASS_SPEC { | |
| 2361 | 51 friend class hrs_ext_msg; |
| 2152 | 52 |
| 53 protected: | |
| 54 static size_t calculate_region_num(HeapRegion* hr); | |
| 55 | |
| 56 static size_t _unrealistically_long_length; | |
| 57 | |
| 58 // The number of regions added to the set. If the set contains | |
| 59 // only humongous regions, this reflects only 'starts humongous' | |
| 60 // regions and does not include 'continues humongous' ones. | |
| 61 size_t _length; | |
| 62 | |
| 63 // The total number of regions represented by the set. If the set | |
| 64 // does not contain humongous regions, this should be the same as | |
| 65 // _length. If the set contains only humongous regions, this will | |
| 66 // include the 'continues humongous' regions. | |
| 67 size_t _region_num; | |
| 68 | |
| 69 // We don't keep track of the total capacity explicitly, we instead | |
| 70 // recalculate it based on _region_num and the heap region size. | |
| 71 | |
| 72 // The sum of used bytes in the all the regions in the set. | |
| 73 size_t _total_used_bytes; | |
| 74 | |
| 75 const char* _name; | |
| 76 | |
| 77 bool _verify_in_progress; | |
| 78 size_t _calc_length; | |
| 79 size_t _calc_region_num; | |
| 80 size_t _calc_total_capacity_bytes; | |
| 81 size_t _calc_total_used_bytes; | |
| 82 | |
| 83 // verify_region() is used to ensure that the contents of a region | |
| 84 // added to / removed from a set are consistent. Different sets | |
| 85 // make different assumptions about the regions added to them. So | |
| 86 // each set can override verify_region_extra(), which is called | |
| 87 // from verify_region(), and do any extra verification it needs to | |
| 88 // perform in that. | |
| 89 virtual const char* verify_region_extra(HeapRegion* hr) { return NULL; } | |
| 90 bool verify_region(HeapRegion* hr, | |
| 91 HeapRegionSetBase* expected_containing_set); | |
| 92 | |
| 93 // Indicates whether all regions in the set should be humongous or | |
| 94 // not. Only used during verification. | |
| 95 virtual bool regions_humongous() = 0; | |
| 96 | |
| 97 // Indicates whether all regions in the set should be empty or | |
| 98 // not. Only used during verification. | |
| 99 virtual bool regions_empty() = 0; | |
| 100 | |
| 101 // Subclasses can optionally override this to do MT safety protocol | |
| 102 // checks. It is called in an assert from all methods that perform | |
| 103 // updates on the set (and subclasses should also call it too). | |
| 104 virtual bool check_mt_safety() { return true; } | |
| 105 | |
| 106 // fill_in_ext_msg() writes the the values of the set's attributes | |
| 2361 | 107 // in the custom err_msg (hrs_ext_msg). fill_in_ext_msg_extra() |
| 2152 | 108 // allows subclasses to append further information. |
| 2361 | 109 virtual void fill_in_ext_msg_extra(hrs_ext_msg* msg) { } |
| 110 void fill_in_ext_msg(hrs_ext_msg* msg, const char* message); | |
| 2152 | 111 |
| 112 // It updates the fields of the set to reflect hr being added to | |
| 113 // the set. | |
| 114 inline void update_for_addition(HeapRegion* hr); | |
| 115 | |
| 116 // It updates the fields of the set to reflect hr being added to | |
| 117 // the set and tags the region appropriately. | |
| 118 inline void add_internal(HeapRegion* hr); | |
| 119 | |
| 120 // It updates the fields of the set to reflect hr being removed | |
| 121 // from the set. | |
| 122 inline void update_for_removal(HeapRegion* hr); | |
| 123 | |
| 124 // It updates the fields of the set to reflect hr being removed | |
| 125 // from the set and tags the region appropriately. | |
| 126 inline void remove_internal(HeapRegion* hr); | |
| 127 | |
| 128 // It clears all the fields of the sets. Note: it will not iterate | |
| 129 // over the set and remove regions from it. It assumes that the | |
| 130 // caller has already done so. It will literally just clear the fields. | |
| 131 virtual void clear(); | |
| 132 | |
| 133 HeapRegionSetBase(const char* name); | |
| 134 | |
| 135 public: | |
| 136 static void set_unrealistically_long_length(size_t len); | |
| 137 | |
| 138 const char* name() { return _name; } | |
| 139 | |
| 140 size_t length() { return _length; } | |
| 141 | |
| 142 bool is_empty() { return _length == 0; } | |
| 143 | |
| 144 size_t region_num() { return _region_num; } | |
| 145 | |
| 146 size_t total_capacity_bytes() { | |
| 147 return region_num() << HeapRegion::LogOfHRGrainBytes; | |
| 148 } | |
| 149 | |
| 150 size_t total_used_bytes() { return _total_used_bytes; } | |
| 151 | |
| 152 virtual void verify(); | |
| 153 void verify_start(); | |
| 154 void verify_next_region(HeapRegion* hr); | |
| 155 void verify_end(); | |
| 156 | |
| 157 #if HEAP_REGION_SET_FORCE_VERIFY | |
| 158 void verify_optional() { | |
| 159 verify(); | |
| 160 } | |
| 161 #else // HEAP_REGION_SET_FORCE_VERIFY | |
| 162 void verify_optional() { } | |
| 163 #endif // HEAP_REGION_SET_FORCE_VERIFY | |
| 164 | |
| 165 virtual void print_on(outputStream* out, bool print_contents = false); | |
| 166 }; | |
| 167 | |
| 168 // Customized err_msg for heap region sets. Apart from a | |
| 169 // assert/guarantee-specific message it also prints out the values of | |
| 170 // the fields of the associated set. This can be very helpful in | |
| 171 // diagnosing failures. | |
| 172 | |
| 2361 | 173 class hrs_ext_msg : public hrs_err_msg { |
| 2152 | 174 public: |
| 2361 | 175 hrs_ext_msg(HeapRegionSetBase* set, const char* message) : hrs_err_msg("") { |
| 2152 | 176 set->fill_in_ext_msg(this, message); |
| 177 } | |
| 178 }; | |
| 179 | |
| 180 // These two macros are provided for convenience, to keep the uses of | |
| 181 // these two asserts a bit more concise. | |
| 182 | |
| 2361 | 183 #define hrs_assert_mt_safety_ok(_set_) \ |
| 2152 | 184 do { \ |
| 2361 | 185 assert((_set_)->check_mt_safety(), hrs_ext_msg((_set_), "MT safety")); \ |
| 2152 | 186 } while (0) |
| 187 | |
| 2361 | 188 #define hrs_assert_region_ok(_set_, _hr_, _expected_) \ |
| 2152 | 189 do { \ |
| 190 assert((_set_)->verify_region((_hr_), (_expected_)), \ | |
| 2361 | 191 hrs_ext_msg((_set_), "region verification")); \ |
| 2152 | 192 } while (0) |
| 193 | |
| 194 //////////////////// HeapRegionSet //////////////////// | |
| 195 | |
| 2361 | 196 #define hrs_assert_sets_match(_set1_, _set2_) \ |
| 2152 | 197 do { \ |
| 198 assert(((_set1_)->regions_humongous() == \ | |
| 199 (_set2_)->regions_humongous()) && \ | |
| 200 ((_set1_)->regions_empty() == (_set2_)->regions_empty()), \ | |
| 2361 | 201 hrs_err_msg("the contents of set %s and set %s should match", \ |
| 2152 | 202 (_set1_)->name(), (_set2_)->name())); \ |
| 203 } while (0) | |
| 204 | |
| 205 // This class represents heap region sets whose members are not | |
| 206 // explicitly tracked. It's helpful to group regions using such sets | |
| 207 // so that we can reason about all the region groups in the heap using | |
| 208 // the same interface (namely, the HeapRegionSetBase API). | |
| 209 | |
| 210 class HeapRegionSet : public HeapRegionSetBase { | |
| 211 protected: | |
| 212 virtual const char* verify_region_extra(HeapRegion* hr) { | |
| 213 if (hr->next() != NULL) { | |
| 214 return "next() should always be NULL as we do not link the regions"; | |
| 215 } | |
| 216 | |
| 217 return HeapRegionSetBase::verify_region_extra(hr); | |
| 218 } | |
| 219 | |
| 220 HeapRegionSet(const char* name) : HeapRegionSetBase(name) { | |
| 221 clear(); | |
| 222 } | |
| 223 | |
| 224 public: | |
| 225 // It adds hr to the set. The region should not be a member of | |
| 226 // another set. | |
| 227 inline void add(HeapRegion* hr); | |
| 228 | |
| 229 // It removes hr from the set. The region should be a member of | |
| 230 // this set. | |
| 231 inline void remove(HeapRegion* hr); | |
| 232 | |
| 233 // It removes a region from the set. Instead of updating the fields | |
| 234 // of the set to reflect this removal, it accumulates the updates | |
| 235 // in proxy_set. The idea is that proxy_set is thread-local to | |
| 236 // avoid multiple threads updating the fields of the set | |
| 237 // concurrently and having to synchronize. The method | |
| 238 // update_from_proxy() will update the fields of the set from the | |
| 239 // proxy_set. | |
| 240 inline void remove_with_proxy(HeapRegion* hr, HeapRegionSet* proxy_set); | |
| 241 | |
| 242 // After multiple calls to remove_with_proxy() the updates to the | |
| 243 // fields of the set are accumulated in proxy_set. This call | |
| 244 // updates the fields of the set from proxy_set. | |
| 245 void update_from_proxy(HeapRegionSet* proxy_set); | |
| 246 }; | |
| 247 | |
| 248 //////////////////// HeapRegionLinkedList //////////////////// | |
| 249 | |
| 250 // A set that links all the regions added to it in a singly-linked | |
| 251 // list. We should try to avoid doing operations that iterate over | |
| 252 // such lists in performance critical paths. Typically we should | |
| 253 // add / remove one region at a time or concatenate two lists. All | |
| 254 // those operations are done in constant time. | |
| 255 | |
| 256 class HeapRegionLinkedListIterator; | |
| 257 | |
| 258 class HeapRegionLinkedList : public HeapRegionSetBase { | |
| 259 friend class HeapRegionLinkedListIterator; | |
| 260 | |
| 261 private: | |
| 262 HeapRegion* _head; | |
| 263 HeapRegion* _tail; | |
| 264 | |
| 265 // These are provided for use by the friend classes. | |
| 266 HeapRegion* head() { return _head; } | |
| 267 HeapRegion* tail() { return _tail; } | |
| 268 | |
| 269 protected: | |
| 2361 | 270 virtual void fill_in_ext_msg_extra(hrs_ext_msg* msg); |
| 2152 | 271 |
| 272 // See the comment for HeapRegionSetBase::clear() | |
| 273 virtual void clear(); | |
| 274 | |
| 275 HeapRegionLinkedList(const char* name) : HeapRegionSetBase(name) { | |
| 276 clear(); | |
| 277 } | |
| 278 | |
| 279 public: | |
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280 // It adds hr to the list as the new head. The region should not be |
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281 // a member of another set. |
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282 inline void add_as_head(HeapRegion* hr); |
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283 |
| 2152 | 284 // It adds hr to the list as the new tail. The region should not be |
| 285 // a member of another set. | |
| 286 inline void add_as_tail(HeapRegion* hr); | |
| 287 | |
| 288 // It removes and returns the head of the list. It assumes that the | |
| 289 // list is not empty so it will return a non-NULL value. | |
| 290 inline HeapRegion* remove_head(); | |
| 291 | |
| 292 // Convenience method. | |
| 293 inline HeapRegion* remove_head_or_null(); | |
| 294 | |
| 295 // It moves the regions from from_list to this list and empties | |
| 296 // from_list. The new regions will appear in the same order as they | |
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297 // were in from_list and be linked in the beginning of this list. |
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298 void add_as_head(HeapRegionLinkedList* from_list); |
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299 |
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300 // It moves the regions from from_list to this list and empties |
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301 // from_list. The new regions will appear in the same order as they |
| 2152 | 302 // were in from_list and be linked in the end of this list. |
| 303 void add_as_tail(HeapRegionLinkedList* from_list); | |
| 304 | |
| 305 // It empties the list by removing all regions from it. | |
| 306 void remove_all(); | |
| 307 | |
| 308 // It removes all regions in the list that are pending for removal | |
| 309 // (i.e., they have been tagged with "pending_removal"). The list | |
| 310 // must not be empty, target_count should reflect the exact number | |
| 311 // of regions that are pending for removal in the list, and | |
| 312 // target_count should be > 1 (currently, we never need to remove a | |
| 313 // single region using this). | |
| 314 void remove_all_pending(size_t target_count); | |
| 315 | |
| 316 virtual void verify(); | |
| 317 | |
| 318 virtual void print_on(outputStream* out, bool print_contents = false); | |
| 319 }; | |
| 320 | |
| 2361 | 321 //////////////////// HeapRegionLinkedListIterator //////////////////// |
| 2152 | 322 |
| 2361 | 323 // Iterator class that provides a convenient way to iterate over the |
| 324 // regions of a HeapRegionLinkedList instance. | |
| 2152 | 325 |
| 326 class HeapRegionLinkedListIterator : public StackObj { | |
| 327 private: | |
| 328 HeapRegionLinkedList* _list; | |
| 329 HeapRegion* _curr; | |
| 330 | |
| 331 public: | |
| 332 bool more_available() { | |
| 333 return _curr != NULL; | |
| 334 } | |
| 335 | |
| 336 HeapRegion* get_next() { | |
| 337 assert(more_available(), | |
| 338 "get_next() should be called when more regions are available"); | |
| 339 | |
| 340 // If we are going to introduce a count in the iterator we should | |
| 341 // do the "cycle" check. | |
| 342 | |
| 343 HeapRegion* hr = _curr; | |
| 344 assert(_list->verify_region(hr, _list), "region verification"); | |
| 345 _curr = hr->next(); | |
| 346 return hr; | |
| 347 } | |
| 348 | |
| 349 HeapRegionLinkedListIterator(HeapRegionLinkedList* list) | |
| 350 : _curr(NULL), _list(list) { | |
| 351 _curr = list->head(); | |
| 352 } | |
| 353 }; | |
| 354 | |
| 355 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSET_HPP |