Mercurial > hg > truffle
annotate src/share/vm/memory/referenceProcessor.hpp @ 2369:92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
Summary: Use _max_num_q = max(discovery_degree, processing_degree), and let balance_queues() redistribute from discovery_degree to processing_degree of queues. This should also allow a more dynamic and flexible parallelism policy in the future.
Reviewed-by: jmasa, johnc
| author | ysr |
|---|---|
| date | Thu, 17 Mar 2011 10:32:46 -0700 |
| parents | 8df09fb45352 |
| children | c2bf0120ee5d |
| rev | line source |
|---|---|
| 0 | 1 /* |
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2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #ifndef SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |
| 26 #define SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP | |
| 27 | |
| 28 #include "memory/referencePolicy.hpp" | |
| 29 #include "oops/instanceRefKlass.hpp" | |
| 30 | |
| 0 | 31 // ReferenceProcessor class encapsulates the per-"collector" processing |
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32 // of java.lang.Reference objects for GC. The interface is useful for supporting |
| 0 | 33 // a generational abstraction, in particular when there are multiple |
| 34 // generations that are being independently collected -- possibly | |
| 35 // concurrently and/or incrementally. Note, however, that the | |
| 36 // ReferenceProcessor class abstracts away from a generational setting | |
| 37 // by using only a heap interval (called "span" below), thus allowing | |
| 38 // its use in a straightforward manner in a general, non-generational | |
| 39 // setting. | |
| 40 // | |
| 41 // The basic idea is that each ReferenceProcessor object concerns | |
| 42 // itself with ("weak") reference processing in a specific "span" | |
| 43 // of the heap of interest to a specific collector. Currently, | |
| 44 // the span is a convex interval of the heap, but, efficiency | |
| 45 // apart, there seems to be no reason it couldn't be extended | |
| 46 // (with appropriate modifications) to any "non-convex interval". | |
| 47 | |
| 48 // forward references | |
| 49 class ReferencePolicy; | |
| 50 class AbstractRefProcTaskExecutor; | |
| 51 class DiscoveredList; | |
| 52 | |
| 53 class ReferenceProcessor : public CHeapObj { | |
| 54 protected: | |
| 55 // End of list marker | |
| 56 static oop _sentinelRef; | |
| 57 MemRegion _span; // (right-open) interval of heap | |
| 58 // subject to wkref discovery | |
| 59 bool _discovering_refs; // true when discovery enabled | |
| 60 bool _discovery_is_atomic; // if discovery is atomic wrt | |
| 61 // other collectors in configuration | |
| 62 bool _discovery_is_mt; // true if reference discovery is MT. | |
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63 // If true, setting "next" field of a discovered refs list requires |
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64 // write barrier(s). (Must be true if used in a collector in which |
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65 // elements of a discovered list may be moved during discovery: for |
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66 // example, a collector like Garbage-First that moves objects during a |
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67 // long-term concurrent marking phase that does weak reference |
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68 // discovery.) |
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69 bool _discovered_list_needs_barrier; |
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70 BarrierSet* _bs; // Cached copy of BarrierSet. |
| 0 | 71 bool _enqueuing_is_done; // true if all weak references enqueued |
| 72 bool _processing_is_mt; // true during phases when | |
| 73 // reference processing is MT. | |
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74 int _next_id; // round-robin mod _num_q counter in |
| 0 | 75 // support of work distribution |
| 76 | |
| 77 // For collectors that do not keep GC marking information | |
| 78 // in the object header, this field holds a closure that | |
| 79 // helps the reference processor determine the reachability | |
| 80 // of an oop (the field is currently initialized to NULL for | |
| 81 // all collectors but the CMS collector). | |
| 82 BoolObjectClosure* _is_alive_non_header; | |
| 83 | |
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84 // Soft ref clearing policies |
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85 // . the default policy |
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86 static ReferencePolicy* _default_soft_ref_policy; |
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87 // . the "clear all" policy |
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88 static ReferencePolicy* _always_clear_soft_ref_policy; |
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89 // . the current policy below is either one of the above |
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90 ReferencePolicy* _current_soft_ref_policy; |
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91 |
| 0 | 92 // The discovered ref lists themselves |
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93 |
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94 // The active MT'ness degree of the queues below |
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95 int _num_q; |
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96 // The maximum MT'ness degree of the queues below |
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97 int _max_num_q; |
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98 // Arrays of lists of oops, one per thread |
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99 DiscoveredList* _discoveredSoftRefs; |
| 0 | 100 DiscoveredList* _discoveredWeakRefs; |
| 101 DiscoveredList* _discoveredFinalRefs; | |
| 102 DiscoveredList* _discoveredPhantomRefs; | |
| 103 | |
| 104 public: | |
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105 int num_q() { return _num_q; } |
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106 int max_num_q() { return _max_num_q; } |
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107 void set_active_mt_degree(int v) { _num_q = v; } |
| 0 | 108 DiscoveredList* discovered_soft_refs() { return _discoveredSoftRefs; } |
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109 static oop sentinel_ref() { return _sentinelRef; } |
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110 static oop* adr_sentinel_ref() { return &_sentinelRef; } |
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111 ReferencePolicy* setup_policy(bool always_clear) { |
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112 _current_soft_ref_policy = always_clear ? |
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113 _always_clear_soft_ref_policy : _default_soft_ref_policy; |
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114 _current_soft_ref_policy->setup(); // snapshot the policy threshold |
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115 return _current_soft_ref_policy; |
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116 } |
| 0 | 117 |
| 118 public: | |
| 119 // Process references with a certain reachability level. | |
| 120 void process_discovered_reflist(DiscoveredList refs_lists[], | |
| 121 ReferencePolicy* policy, | |
| 122 bool clear_referent, | |
| 123 BoolObjectClosure* is_alive, | |
| 124 OopClosure* keep_alive, | |
| 125 VoidClosure* complete_gc, | |
| 126 AbstractRefProcTaskExecutor* task_executor); | |
| 127 | |
| 128 void process_phaseJNI(BoolObjectClosure* is_alive, | |
| 129 OopClosure* keep_alive, | |
| 130 VoidClosure* complete_gc); | |
| 131 | |
| 132 // Work methods used by the method process_discovered_reflist | |
| 133 // Phase1: keep alive all those referents that are otherwise | |
| 134 // dead but which must be kept alive by policy (and their closure). | |
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135 void process_phase1(DiscoveredList& refs_list, |
| 0 | 136 ReferencePolicy* policy, |
| 137 BoolObjectClosure* is_alive, | |
| 138 OopClosure* keep_alive, | |
| 139 VoidClosure* complete_gc); | |
| 140 // Phase2: remove all those references whose referents are | |
| 141 // reachable. | |
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142 inline void process_phase2(DiscoveredList& refs_list, |
| 0 | 143 BoolObjectClosure* is_alive, |
| 144 OopClosure* keep_alive, | |
| 145 VoidClosure* complete_gc) { | |
| 146 if (discovery_is_atomic()) { | |
| 147 // complete_gc is ignored in this case for this phase | |
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148 pp2_work(refs_list, is_alive, keep_alive); |
| 0 | 149 } else { |
| 150 assert(complete_gc != NULL, "Error"); | |
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151 pp2_work_concurrent_discovery(refs_list, is_alive, |
| 0 | 152 keep_alive, complete_gc); |
| 153 } | |
| 154 } | |
| 155 // Work methods in support of process_phase2 | |
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156 void pp2_work(DiscoveredList& refs_list, |
| 0 | 157 BoolObjectClosure* is_alive, |
| 158 OopClosure* keep_alive); | |
| 159 void pp2_work_concurrent_discovery( | |
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160 DiscoveredList& refs_list, |
| 0 | 161 BoolObjectClosure* is_alive, |
| 162 OopClosure* keep_alive, | |
| 163 VoidClosure* complete_gc); | |
| 164 // Phase3: process the referents by either clearing them | |
| 165 // or keeping them alive (and their closure) | |
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166 void process_phase3(DiscoveredList& refs_list, |
| 0 | 167 bool clear_referent, |
| 168 BoolObjectClosure* is_alive, | |
| 169 OopClosure* keep_alive, | |
| 170 VoidClosure* complete_gc); | |
| 171 | |
| 172 // Enqueue references with a certain reachability level | |
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173 void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr); |
| 0 | 174 |
| 175 // "Preclean" all the discovered reference lists | |
| 176 // by removing references with strongly reachable referents. | |
| 177 // The first argument is a predicate on an oop that indicates | |
| 178 // its (strong) reachability and the second is a closure that | |
| 179 // may be used to incrementalize or abort the precleaning process. | |
| 180 // The caller is responsible for taking care of potential | |
| 181 // interference with concurrent operations on these lists | |
| 182 // (or predicates involved) by other threads. Currently | |
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183 // only used by the CMS collector. should_unload_classes is |
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184 // used to aid assertion checking when classes are collected. |
| 0 | 185 void preclean_discovered_references(BoolObjectClosure* is_alive, |
| 186 OopClosure* keep_alive, | |
| 187 VoidClosure* complete_gc, | |
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188 YieldClosure* yield, |
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189 bool should_unload_classes); |
| 0 | 190 |
| 191 // Delete entries in the discovered lists that have | |
| 192 // either a null referent or are not active. Such | |
| 193 // Reference objects can result from the clearing | |
| 194 // or enqueueing of Reference objects concurrent | |
| 195 // with their discovery by a (concurrent) collector. | |
| 196 // For a definition of "active" see java.lang.ref.Reference; | |
| 197 // Refs are born active, become inactive when enqueued, | |
| 198 // and never become active again. The state of being | |
| 199 // active is encoded as follows: A Ref is active | |
| 200 // if and only if its "next" field is NULL. | |
| 201 void clean_up_discovered_references(); | |
| 202 void clean_up_discovered_reflist(DiscoveredList& refs_list); | |
| 203 | |
| 204 // Returns the name of the discovered reference list | |
| 205 // occupying the i / _num_q slot. | |
| 206 const char* list_name(int i); | |
| 207 | |
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208 void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor); |
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209 |
| 0 | 210 protected: |
| 211 // "Preclean" the given discovered reference list | |
| 212 // by removing references with strongly reachable referents. | |
| 213 // Currently used in support of CMS only. | |
| 214 void preclean_discovered_reflist(DiscoveredList& refs_list, | |
| 215 BoolObjectClosure* is_alive, | |
| 216 OopClosure* keep_alive, | |
| 217 VoidClosure* complete_gc, | |
| 218 YieldClosure* yield); | |
| 219 | |
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220 // round-robin mod _num_q (not: _not_ mode _max_num_q) |
| 0 | 221 int next_id() { |
| 222 int id = _next_id; | |
| 223 if (++_next_id == _num_q) { | |
| 224 _next_id = 0; | |
| 225 } | |
| 226 return id; | |
| 227 } | |
| 228 DiscoveredList* get_discovered_list(ReferenceType rt); | |
| 229 inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj, | |
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230 HeapWord* discovered_addr); |
| 0 | 231 void verify_ok_to_handle_reflists() PRODUCT_RETURN; |
| 232 | |
| 233 void abandon_partial_discovered_list(DiscoveredList& refs_list); | |
| 234 | |
| 235 // Calculate the number of jni handles. | |
| 236 unsigned int count_jni_refs(); | |
| 237 | |
| 238 // Balances reference queues. | |
| 239 void balance_queues(DiscoveredList ref_lists[]); | |
| 240 | |
| 241 // Update (advance) the soft ref master clock field. | |
| 242 void update_soft_ref_master_clock(); | |
| 243 | |
| 244 public: | |
| 245 // constructor | |
| 246 ReferenceProcessor(): | |
| 247 _span((HeapWord*)NULL, (HeapWord*)NULL), | |
| 248 _discoveredSoftRefs(NULL), _discoveredWeakRefs(NULL), | |
| 249 _discoveredFinalRefs(NULL), _discoveredPhantomRefs(NULL), | |
| 250 _discovering_refs(false), | |
| 251 _discovery_is_atomic(true), | |
| 252 _enqueuing_is_done(false), | |
| 253 _discovery_is_mt(false), | |
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254 _discovered_list_needs_barrier(false), |
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255 _bs(NULL), |
| 0 | 256 _is_alive_non_header(NULL), |
| 257 _num_q(0), | |
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258 _max_num_q(0), |
| 0 | 259 _processing_is_mt(false), |
| 260 _next_id(0) | |
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261 { } |
| 0 | 262 |
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263 // Default parameters give you a vanilla reference processor. |
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264 ReferenceProcessor(MemRegion span, |
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265 bool mt_processing = false, int mt_processing_degree = 1, |
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266 bool mt_discovery = false, int mt_discovery_degree = 1, |
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267 bool atomic_discovery = true, |
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268 BoolObjectClosure* is_alive_non_header = NULL, |
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269 bool discovered_list_needs_barrier = false); |
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270 |
| 0 | 271 // RefDiscoveryPolicy values |
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272 enum DiscoveryPolicy { |
| 0 | 273 ReferenceBasedDiscovery = 0, |
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274 ReferentBasedDiscovery = 1, |
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275 DiscoveryPolicyMin = ReferenceBasedDiscovery, |
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276 DiscoveryPolicyMax = ReferentBasedDiscovery |
| 0 | 277 }; |
| 278 | |
| 279 static void init_statics(); | |
| 280 | |
| 281 public: | |
| 282 // get and set "is_alive_non_header" field | |
| 283 BoolObjectClosure* is_alive_non_header() { | |
| 284 return _is_alive_non_header; | |
| 285 } | |
| 286 void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) { | |
| 287 _is_alive_non_header = is_alive_non_header; | |
| 288 } | |
| 289 | |
| 290 // get and set span | |
| 291 MemRegion span() { return _span; } | |
| 292 void set_span(MemRegion span) { _span = span; } | |
| 293 | |
| 294 // start and stop weak ref discovery | |
| 295 void enable_discovery() { _discovering_refs = true; } | |
| 296 void disable_discovery() { _discovering_refs = false; } | |
| 297 bool discovery_enabled() { return _discovering_refs; } | |
| 298 | |
| 299 // whether discovery is atomic wrt other collectors | |
| 300 bool discovery_is_atomic() const { return _discovery_is_atomic; } | |
| 301 void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; } | |
| 302 | |
| 303 // whether discovery is done by multiple threads same-old-timeously | |
| 304 bool discovery_is_mt() const { return _discovery_is_mt; } | |
| 305 void set_mt_discovery(bool mt) { _discovery_is_mt = mt; } | |
| 306 | |
| 307 // Whether we are in a phase when _processing_ is MT. | |
| 308 bool processing_is_mt() const { return _processing_is_mt; } | |
| 309 void set_mt_processing(bool mt) { _processing_is_mt = mt; } | |
| 310 | |
| 311 // whether all enqueuing of weak references is complete | |
| 312 bool enqueuing_is_done() { return _enqueuing_is_done; } | |
| 313 void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; } | |
| 314 | |
| 315 // iterate over oops | |
| 316 void weak_oops_do(OopClosure* f); // weak roots | |
| 317 static void oops_do(OopClosure* f); // strong root(s) | |
| 318 | |
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319 // Balance each of the discovered lists. |
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320 void balance_all_queues(); |
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321 |
| 0 | 322 // Discover a Reference object, using appropriate discovery criteria |
| 323 bool discover_reference(oop obj, ReferenceType rt); | |
| 324 | |
| 325 // Process references found during GC (called by the garbage collector) | |
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326 void process_discovered_references(BoolObjectClosure* is_alive, |
| 0 | 327 OopClosure* keep_alive, |
| 328 VoidClosure* complete_gc, | |
| 329 AbstractRefProcTaskExecutor* task_executor); | |
| 330 | |
| 331 public: | |
| 332 // Enqueue references at end of GC (called by the garbage collector) | |
| 333 bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL); | |
| 334 | |
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335 // If a discovery is in process that is being superceded, abandon it: all |
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336 // the discovered lists will be empty, and all the objects on them will |
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337 // have NULL discovered fields. Must be called only at a safepoint. |
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338 void abandon_partial_discovery(); |
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339 |
| 0 | 340 // debugging |
| 341 void verify_no_references_recorded() PRODUCT_RETURN; | |
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342 void verify_referent(oop obj) PRODUCT_RETURN; |
| 0 | 343 static void verify(); |
| 344 | |
| 345 // clear the discovered lists (unlinking each entry). | |
| 346 void clear_discovered_references() PRODUCT_RETURN; | |
| 347 }; | |
| 348 | |
| 349 // A utility class to disable reference discovery in | |
| 350 // the scope which contains it, for given ReferenceProcessor. | |
| 351 class NoRefDiscovery: StackObj { | |
| 352 private: | |
| 353 ReferenceProcessor* _rp; | |
| 354 bool _was_discovering_refs; | |
| 355 public: | |
| 356 NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) { | |
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357 _was_discovering_refs = _rp->discovery_enabled(); |
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358 if (_was_discovering_refs) { |
| 0 | 359 _rp->disable_discovery(); |
| 360 } | |
| 361 } | |
| 362 | |
| 363 ~NoRefDiscovery() { | |
| 364 if (_was_discovering_refs) { | |
| 365 _rp->enable_discovery(); | |
| 366 } | |
| 367 } | |
| 368 }; | |
| 369 | |
| 370 | |
| 371 // A utility class to temporarily mutate the span of the | |
| 372 // given ReferenceProcessor in the scope that contains it. | |
| 373 class ReferenceProcessorSpanMutator: StackObj { | |
| 374 private: | |
| 375 ReferenceProcessor* _rp; | |
| 376 MemRegion _saved_span; | |
| 377 | |
| 378 public: | |
| 379 ReferenceProcessorSpanMutator(ReferenceProcessor* rp, | |
| 380 MemRegion span): | |
| 381 _rp(rp) { | |
| 382 _saved_span = _rp->span(); | |
| 383 _rp->set_span(span); | |
| 384 } | |
| 385 | |
| 386 ~ReferenceProcessorSpanMutator() { | |
| 387 _rp->set_span(_saved_span); | |
| 388 } | |
| 389 }; | |
| 390 | |
| 391 // A utility class to temporarily change the MT'ness of | |
| 392 // reference discovery for the given ReferenceProcessor | |
| 393 // in the scope that contains it. | |
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394 class ReferenceProcessorMTDiscoveryMutator: StackObj { |
| 0 | 395 private: |
| 396 ReferenceProcessor* _rp; | |
| 397 bool _saved_mt; | |
| 398 | |
| 399 public: | |
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400 ReferenceProcessorMTDiscoveryMutator(ReferenceProcessor* rp, |
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401 bool mt): |
| 0 | 402 _rp(rp) { |
| 403 _saved_mt = _rp->discovery_is_mt(); | |
| 404 _rp->set_mt_discovery(mt); | |
| 405 } | |
| 406 | |
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407 ~ReferenceProcessorMTDiscoveryMutator() { |
| 0 | 408 _rp->set_mt_discovery(_saved_mt); |
| 409 } | |
| 410 }; | |
| 411 | |
| 412 | |
| 413 // A utility class to temporarily change the disposition | |
| 414 // of the "is_alive_non_header" closure field of the | |
| 415 // given ReferenceProcessor in the scope that contains it. | |
| 416 class ReferenceProcessorIsAliveMutator: StackObj { | |
| 417 private: | |
| 418 ReferenceProcessor* _rp; | |
| 419 BoolObjectClosure* _saved_cl; | |
| 420 | |
| 421 public: | |
| 422 ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp, | |
| 423 BoolObjectClosure* cl): | |
| 424 _rp(rp) { | |
| 425 _saved_cl = _rp->is_alive_non_header(); | |
| 426 _rp->set_is_alive_non_header(cl); | |
| 427 } | |
| 428 | |
| 429 ~ReferenceProcessorIsAliveMutator() { | |
| 430 _rp->set_is_alive_non_header(_saved_cl); | |
| 431 } | |
| 432 }; | |
| 433 | |
| 434 // A utility class to temporarily change the disposition | |
| 435 // of the "discovery_is_atomic" field of the | |
| 436 // given ReferenceProcessor in the scope that contains it. | |
| 437 class ReferenceProcessorAtomicMutator: StackObj { | |
| 438 private: | |
| 439 ReferenceProcessor* _rp; | |
| 440 bool _saved_atomic_discovery; | |
| 441 | |
| 442 public: | |
| 443 ReferenceProcessorAtomicMutator(ReferenceProcessor* rp, | |
| 444 bool atomic): | |
| 445 _rp(rp) { | |
| 446 _saved_atomic_discovery = _rp->discovery_is_atomic(); | |
| 447 _rp->set_atomic_discovery(atomic); | |
| 448 } | |
| 449 | |
| 450 ~ReferenceProcessorAtomicMutator() { | |
| 451 _rp->set_atomic_discovery(_saved_atomic_discovery); | |
| 452 } | |
| 453 }; | |
| 454 | |
| 455 | |
| 456 // A utility class to temporarily change the MT processing | |
| 457 // disposition of the given ReferenceProcessor instance | |
| 458 // in the scope that contains it. | |
| 459 class ReferenceProcessorMTProcMutator: StackObj { | |
| 460 private: | |
| 461 ReferenceProcessor* _rp; | |
| 462 bool _saved_mt; | |
| 463 | |
| 464 public: | |
| 465 ReferenceProcessorMTProcMutator(ReferenceProcessor* rp, | |
| 466 bool mt): | |
| 467 _rp(rp) { | |
| 468 _saved_mt = _rp->processing_is_mt(); | |
| 469 _rp->set_mt_processing(mt); | |
| 470 } | |
| 471 | |
| 472 ~ReferenceProcessorMTProcMutator() { | |
| 473 _rp->set_mt_processing(_saved_mt); | |
| 474 } | |
| 475 }; | |
| 476 | |
| 477 | |
| 478 // This class is an interface used to implement task execution for the | |
| 479 // reference processing. | |
| 480 class AbstractRefProcTaskExecutor { | |
| 481 public: | |
| 482 | |
| 483 // Abstract tasks to execute. | |
| 484 class ProcessTask; | |
| 485 class EnqueueTask; | |
| 486 | |
| 487 // Executes a task using worker threads. | |
| 488 virtual void execute(ProcessTask& task) = 0; | |
| 489 virtual void execute(EnqueueTask& task) = 0; | |
| 490 | |
| 491 // Switch to single threaded mode. | |
| 492 virtual void set_single_threaded_mode() { }; | |
| 493 }; | |
| 494 | |
| 495 // Abstract reference processing task to execute. | |
| 496 class AbstractRefProcTaskExecutor::ProcessTask { | |
| 497 protected: | |
| 498 ProcessTask(ReferenceProcessor& ref_processor, | |
| 499 DiscoveredList refs_lists[], | |
| 500 bool marks_oops_alive) | |
| 501 : _ref_processor(ref_processor), | |
| 502 _refs_lists(refs_lists), | |
| 503 _marks_oops_alive(marks_oops_alive) | |
| 504 { } | |
| 505 | |
| 506 public: | |
| 507 virtual void work(unsigned int work_id, BoolObjectClosure& is_alive, | |
| 508 OopClosure& keep_alive, | |
| 509 VoidClosure& complete_gc) = 0; | |
| 510 | |
| 511 // Returns true if a task marks some oops as alive. | |
| 512 bool marks_oops_alive() const | |
| 513 { return _marks_oops_alive; } | |
| 514 | |
| 515 protected: | |
| 516 ReferenceProcessor& _ref_processor; | |
| 517 DiscoveredList* _refs_lists; | |
| 518 const bool _marks_oops_alive; | |
| 519 }; | |
| 520 | |
| 521 // Abstract reference processing task to execute. | |
| 522 class AbstractRefProcTaskExecutor::EnqueueTask { | |
| 523 protected: | |
| 524 EnqueueTask(ReferenceProcessor& ref_processor, | |
| 525 DiscoveredList refs_lists[], | |
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526 HeapWord* pending_list_addr, |
| 0 | 527 oop sentinel_ref, |
| 528 int n_queues) | |
| 529 : _ref_processor(ref_processor), | |
| 530 _refs_lists(refs_lists), | |
| 531 _pending_list_addr(pending_list_addr), | |
| 532 _sentinel_ref(sentinel_ref), | |
| 533 _n_queues(n_queues) | |
| 534 { } | |
| 535 | |
| 536 public: | |
| 537 virtual void work(unsigned int work_id) = 0; | |
| 538 | |
| 539 protected: | |
| 540 ReferenceProcessor& _ref_processor; | |
| 541 DiscoveredList* _refs_lists; | |
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542 HeapWord* _pending_list_addr; |
| 0 | 543 oop _sentinel_ref; |
| 544 int _n_queues; | |
| 545 }; | |
| 1972 | 546 |
| 547 #endif // SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |