Sun, 13 Apr 2008 17:43:42 -0400
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold
duke@435 | 1 | /* |
duke@435 | 2 | * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | // ReferenceProcessor class encapsulates the per-"collector" processing |
duke@435 | 26 | // of "weak" references for GC. The interface is useful for supporting |
duke@435 | 27 | // a generational abstraction, in particular when there are multiple |
duke@435 | 28 | // generations that are being independently collected -- possibly |
duke@435 | 29 | // concurrently and/or incrementally. Note, however, that the |
duke@435 | 30 | // ReferenceProcessor class abstracts away from a generational setting |
duke@435 | 31 | // by using only a heap interval (called "span" below), thus allowing |
duke@435 | 32 | // its use in a straightforward manner in a general, non-generational |
duke@435 | 33 | // setting. |
duke@435 | 34 | // |
duke@435 | 35 | // The basic idea is that each ReferenceProcessor object concerns |
duke@435 | 36 | // itself with ("weak") reference processing in a specific "span" |
duke@435 | 37 | // of the heap of interest to a specific collector. Currently, |
duke@435 | 38 | // the span is a convex interval of the heap, but, efficiency |
duke@435 | 39 | // apart, there seems to be no reason it couldn't be extended |
duke@435 | 40 | // (with appropriate modifications) to any "non-convex interval". |
duke@435 | 41 | |
duke@435 | 42 | // forward references |
duke@435 | 43 | class ReferencePolicy; |
duke@435 | 44 | class AbstractRefProcTaskExecutor; |
duke@435 | 45 | class DiscoveredList; |
duke@435 | 46 | |
duke@435 | 47 | class ReferenceProcessor : public CHeapObj { |
duke@435 | 48 | protected: |
duke@435 | 49 | // End of list marker |
duke@435 | 50 | static oop _sentinelRef; |
duke@435 | 51 | MemRegion _span; // (right-open) interval of heap |
duke@435 | 52 | // subject to wkref discovery |
duke@435 | 53 | bool _discovering_refs; // true when discovery enabled |
duke@435 | 54 | bool _discovery_is_atomic; // if discovery is atomic wrt |
duke@435 | 55 | // other collectors in configuration |
duke@435 | 56 | bool _discovery_is_mt; // true if reference discovery is MT. |
duke@435 | 57 | bool _enqueuing_is_done; // true if all weak references enqueued |
duke@435 | 58 | bool _processing_is_mt; // true during phases when |
duke@435 | 59 | // reference processing is MT. |
duke@435 | 60 | int _next_id; // round-robin counter in |
duke@435 | 61 | // support of work distribution |
duke@435 | 62 | |
duke@435 | 63 | // For collectors that do not keep GC marking information |
duke@435 | 64 | // in the object header, this field holds a closure that |
duke@435 | 65 | // helps the reference processor determine the reachability |
duke@435 | 66 | // of an oop (the field is currently initialized to NULL for |
duke@435 | 67 | // all collectors but the CMS collector). |
duke@435 | 68 | BoolObjectClosure* _is_alive_non_header; |
duke@435 | 69 | |
duke@435 | 70 | // The discovered ref lists themselves |
coleenp@548 | 71 | |
coleenp@548 | 72 | // The MT'ness degree of the queues below |
coleenp@548 | 73 | int _num_q; |
coleenp@548 | 74 | // Arrays of lists of oops, one per thread |
coleenp@548 | 75 | DiscoveredList* _discoveredSoftRefs; |
duke@435 | 76 | DiscoveredList* _discoveredWeakRefs; |
duke@435 | 77 | DiscoveredList* _discoveredFinalRefs; |
duke@435 | 78 | DiscoveredList* _discoveredPhantomRefs; |
duke@435 | 79 | |
duke@435 | 80 | public: |
coleenp@548 | 81 | int num_q() { return _num_q; } |
duke@435 | 82 | DiscoveredList* discovered_soft_refs() { return _discoveredSoftRefs; } |
coleenp@548 | 83 | static oop sentinel_ref() { return _sentinelRef; } |
coleenp@548 | 84 | static oop* adr_sentinel_ref() { return &_sentinelRef; } |
duke@435 | 85 | |
duke@435 | 86 | public: |
duke@435 | 87 | // Process references with a certain reachability level. |
duke@435 | 88 | void process_discovered_reflist(DiscoveredList refs_lists[], |
duke@435 | 89 | ReferencePolicy* policy, |
duke@435 | 90 | bool clear_referent, |
duke@435 | 91 | BoolObjectClosure* is_alive, |
duke@435 | 92 | OopClosure* keep_alive, |
duke@435 | 93 | VoidClosure* complete_gc, |
duke@435 | 94 | AbstractRefProcTaskExecutor* task_executor); |
duke@435 | 95 | |
duke@435 | 96 | void process_phaseJNI(BoolObjectClosure* is_alive, |
duke@435 | 97 | OopClosure* keep_alive, |
duke@435 | 98 | VoidClosure* complete_gc); |
duke@435 | 99 | |
duke@435 | 100 | // Work methods used by the method process_discovered_reflist |
duke@435 | 101 | // Phase1: keep alive all those referents that are otherwise |
duke@435 | 102 | // dead but which must be kept alive by policy (and their closure). |
coleenp@548 | 103 | void process_phase1(DiscoveredList& refs_list, |
duke@435 | 104 | ReferencePolicy* policy, |
duke@435 | 105 | BoolObjectClosure* is_alive, |
duke@435 | 106 | OopClosure* keep_alive, |
duke@435 | 107 | VoidClosure* complete_gc); |
duke@435 | 108 | // Phase2: remove all those references whose referents are |
duke@435 | 109 | // reachable. |
coleenp@548 | 110 | inline void process_phase2(DiscoveredList& refs_list, |
duke@435 | 111 | BoolObjectClosure* is_alive, |
duke@435 | 112 | OopClosure* keep_alive, |
duke@435 | 113 | VoidClosure* complete_gc) { |
duke@435 | 114 | if (discovery_is_atomic()) { |
duke@435 | 115 | // complete_gc is ignored in this case for this phase |
coleenp@548 | 116 | pp2_work(refs_list, is_alive, keep_alive); |
duke@435 | 117 | } else { |
duke@435 | 118 | assert(complete_gc != NULL, "Error"); |
coleenp@548 | 119 | pp2_work_concurrent_discovery(refs_list, is_alive, |
duke@435 | 120 | keep_alive, complete_gc); |
duke@435 | 121 | } |
duke@435 | 122 | } |
duke@435 | 123 | // Work methods in support of process_phase2 |
coleenp@548 | 124 | void pp2_work(DiscoveredList& refs_list, |
duke@435 | 125 | BoolObjectClosure* is_alive, |
duke@435 | 126 | OopClosure* keep_alive); |
duke@435 | 127 | void pp2_work_concurrent_discovery( |
coleenp@548 | 128 | DiscoveredList& refs_list, |
duke@435 | 129 | BoolObjectClosure* is_alive, |
duke@435 | 130 | OopClosure* keep_alive, |
duke@435 | 131 | VoidClosure* complete_gc); |
duke@435 | 132 | // Phase3: process the referents by either clearing them |
duke@435 | 133 | // or keeping them alive (and their closure) |
coleenp@548 | 134 | void process_phase3(DiscoveredList& refs_list, |
duke@435 | 135 | bool clear_referent, |
duke@435 | 136 | BoolObjectClosure* is_alive, |
duke@435 | 137 | OopClosure* keep_alive, |
duke@435 | 138 | VoidClosure* complete_gc); |
duke@435 | 139 | |
duke@435 | 140 | // Enqueue references with a certain reachability level |
coleenp@548 | 141 | void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr); |
duke@435 | 142 | |
duke@435 | 143 | // "Preclean" all the discovered reference lists |
duke@435 | 144 | // by removing references with strongly reachable referents. |
duke@435 | 145 | // The first argument is a predicate on an oop that indicates |
duke@435 | 146 | // its (strong) reachability and the second is a closure that |
duke@435 | 147 | // may be used to incrementalize or abort the precleaning process. |
duke@435 | 148 | // The caller is responsible for taking care of potential |
duke@435 | 149 | // interference with concurrent operations on these lists |
duke@435 | 150 | // (or predicates involved) by other threads. Currently |
duke@435 | 151 | // only used by the CMS collector. |
duke@435 | 152 | void preclean_discovered_references(BoolObjectClosure* is_alive, |
duke@435 | 153 | OopClosure* keep_alive, |
duke@435 | 154 | VoidClosure* complete_gc, |
duke@435 | 155 | YieldClosure* yield); |
duke@435 | 156 | |
duke@435 | 157 | // Delete entries in the discovered lists that have |
duke@435 | 158 | // either a null referent or are not active. Such |
duke@435 | 159 | // Reference objects can result from the clearing |
duke@435 | 160 | // or enqueueing of Reference objects concurrent |
duke@435 | 161 | // with their discovery by a (concurrent) collector. |
duke@435 | 162 | // For a definition of "active" see java.lang.ref.Reference; |
duke@435 | 163 | // Refs are born active, become inactive when enqueued, |
duke@435 | 164 | // and never become active again. The state of being |
duke@435 | 165 | // active is encoded as follows: A Ref is active |
duke@435 | 166 | // if and only if its "next" field is NULL. |
duke@435 | 167 | void clean_up_discovered_references(); |
duke@435 | 168 | void clean_up_discovered_reflist(DiscoveredList& refs_list); |
duke@435 | 169 | |
duke@435 | 170 | // Returns the name of the discovered reference list |
duke@435 | 171 | // occupying the i / _num_q slot. |
duke@435 | 172 | const char* list_name(int i); |
duke@435 | 173 | |
coleenp@548 | 174 | void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor); |
coleenp@548 | 175 | |
duke@435 | 176 | protected: |
duke@435 | 177 | // "Preclean" the given discovered reference list |
duke@435 | 178 | // by removing references with strongly reachable referents. |
duke@435 | 179 | // Currently used in support of CMS only. |
duke@435 | 180 | void preclean_discovered_reflist(DiscoveredList& refs_list, |
duke@435 | 181 | BoolObjectClosure* is_alive, |
duke@435 | 182 | OopClosure* keep_alive, |
duke@435 | 183 | VoidClosure* complete_gc, |
duke@435 | 184 | YieldClosure* yield); |
duke@435 | 185 | |
duke@435 | 186 | int next_id() { |
duke@435 | 187 | int id = _next_id; |
duke@435 | 188 | if (++_next_id == _num_q) { |
duke@435 | 189 | _next_id = 0; |
duke@435 | 190 | } |
duke@435 | 191 | return id; |
duke@435 | 192 | } |
duke@435 | 193 | DiscoveredList* get_discovered_list(ReferenceType rt); |
duke@435 | 194 | inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj, |
coleenp@548 | 195 | HeapWord* discovered_addr); |
duke@435 | 196 | void verify_ok_to_handle_reflists() PRODUCT_RETURN; |
duke@435 | 197 | |
duke@435 | 198 | void abandon_partial_discovered_list(DiscoveredList& refs_list); |
duke@435 | 199 | void abandon_partial_discovered_list_arr(DiscoveredList refs_lists[]); |
duke@435 | 200 | |
duke@435 | 201 | // Calculate the number of jni handles. |
duke@435 | 202 | unsigned int count_jni_refs(); |
duke@435 | 203 | |
duke@435 | 204 | // Balances reference queues. |
duke@435 | 205 | void balance_queues(DiscoveredList ref_lists[]); |
duke@435 | 206 | |
duke@435 | 207 | // Update (advance) the soft ref master clock field. |
duke@435 | 208 | void update_soft_ref_master_clock(); |
duke@435 | 209 | |
duke@435 | 210 | public: |
duke@435 | 211 | // constructor |
duke@435 | 212 | ReferenceProcessor(): |
duke@435 | 213 | _span((HeapWord*)NULL, (HeapWord*)NULL), |
duke@435 | 214 | _discoveredSoftRefs(NULL), _discoveredWeakRefs(NULL), |
duke@435 | 215 | _discoveredFinalRefs(NULL), _discoveredPhantomRefs(NULL), |
duke@435 | 216 | _discovering_refs(false), |
duke@435 | 217 | _discovery_is_atomic(true), |
duke@435 | 218 | _enqueuing_is_done(false), |
duke@435 | 219 | _discovery_is_mt(false), |
duke@435 | 220 | _is_alive_non_header(NULL), |
duke@435 | 221 | _num_q(0), |
duke@435 | 222 | _processing_is_mt(false), |
duke@435 | 223 | _next_id(0) |
duke@435 | 224 | {} |
duke@435 | 225 | |
duke@435 | 226 | ReferenceProcessor(MemRegion span, bool atomic_discovery, |
duke@435 | 227 | bool mt_discovery, int mt_degree = 1, |
duke@435 | 228 | bool mt_processing = false); |
duke@435 | 229 | |
duke@435 | 230 | // Allocates and initializes a reference processor. |
duke@435 | 231 | static ReferenceProcessor* create_ref_processor( |
duke@435 | 232 | MemRegion span, |
duke@435 | 233 | bool atomic_discovery, |
duke@435 | 234 | bool mt_discovery, |
duke@435 | 235 | BoolObjectClosure* is_alive_non_header = NULL, |
duke@435 | 236 | int parallel_gc_threads = 1, |
duke@435 | 237 | bool mt_processing = false); |
duke@435 | 238 | |
duke@435 | 239 | // RefDiscoveryPolicy values |
duke@435 | 240 | enum { |
duke@435 | 241 | ReferenceBasedDiscovery = 0, |
duke@435 | 242 | ReferentBasedDiscovery = 1 |
duke@435 | 243 | }; |
duke@435 | 244 | |
duke@435 | 245 | static void init_statics(); |
duke@435 | 246 | |
duke@435 | 247 | public: |
duke@435 | 248 | // get and set "is_alive_non_header" field |
duke@435 | 249 | BoolObjectClosure* is_alive_non_header() { |
duke@435 | 250 | return _is_alive_non_header; |
duke@435 | 251 | } |
duke@435 | 252 | void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) { |
duke@435 | 253 | _is_alive_non_header = is_alive_non_header; |
duke@435 | 254 | } |
duke@435 | 255 | |
duke@435 | 256 | // get and set span |
duke@435 | 257 | MemRegion span() { return _span; } |
duke@435 | 258 | void set_span(MemRegion span) { _span = span; } |
duke@435 | 259 | |
duke@435 | 260 | // start and stop weak ref discovery |
duke@435 | 261 | void enable_discovery() { _discovering_refs = true; } |
duke@435 | 262 | void disable_discovery() { _discovering_refs = false; } |
duke@435 | 263 | bool discovery_enabled() { return _discovering_refs; } |
duke@435 | 264 | |
duke@435 | 265 | // whether discovery is atomic wrt other collectors |
duke@435 | 266 | bool discovery_is_atomic() const { return _discovery_is_atomic; } |
duke@435 | 267 | void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; } |
duke@435 | 268 | |
duke@435 | 269 | // whether discovery is done by multiple threads same-old-timeously |
duke@435 | 270 | bool discovery_is_mt() const { return _discovery_is_mt; } |
duke@435 | 271 | void set_mt_discovery(bool mt) { _discovery_is_mt = mt; } |
duke@435 | 272 | |
duke@435 | 273 | // Whether we are in a phase when _processing_ is MT. |
duke@435 | 274 | bool processing_is_mt() const { return _processing_is_mt; } |
duke@435 | 275 | void set_mt_processing(bool mt) { _processing_is_mt = mt; } |
duke@435 | 276 | |
duke@435 | 277 | // whether all enqueuing of weak references is complete |
duke@435 | 278 | bool enqueuing_is_done() { return _enqueuing_is_done; } |
duke@435 | 279 | void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; } |
duke@435 | 280 | |
duke@435 | 281 | // iterate over oops |
duke@435 | 282 | void weak_oops_do(OopClosure* f); // weak roots |
duke@435 | 283 | static void oops_do(OopClosure* f); // strong root(s) |
duke@435 | 284 | |
duke@435 | 285 | // Discover a Reference object, using appropriate discovery criteria |
duke@435 | 286 | bool discover_reference(oop obj, ReferenceType rt); |
duke@435 | 287 | |
duke@435 | 288 | // Process references found during GC (called by the garbage collector) |
duke@435 | 289 | void process_discovered_references(ReferencePolicy* policy, |
duke@435 | 290 | BoolObjectClosure* is_alive, |
duke@435 | 291 | OopClosure* keep_alive, |
duke@435 | 292 | VoidClosure* complete_gc, |
duke@435 | 293 | AbstractRefProcTaskExecutor* task_executor); |
duke@435 | 294 | |
duke@435 | 295 | public: |
duke@435 | 296 | // Enqueue references at end of GC (called by the garbage collector) |
duke@435 | 297 | bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL); |
duke@435 | 298 | |
duke@435 | 299 | // debugging |
duke@435 | 300 | void verify_no_references_recorded() PRODUCT_RETURN; |
duke@435 | 301 | static void verify(); |
duke@435 | 302 | |
duke@435 | 303 | // clear the discovered lists (unlinking each entry). |
duke@435 | 304 | void clear_discovered_references() PRODUCT_RETURN; |
duke@435 | 305 | }; |
duke@435 | 306 | |
duke@435 | 307 | // A utility class to disable reference discovery in |
duke@435 | 308 | // the scope which contains it, for given ReferenceProcessor. |
duke@435 | 309 | class NoRefDiscovery: StackObj { |
duke@435 | 310 | private: |
duke@435 | 311 | ReferenceProcessor* _rp; |
duke@435 | 312 | bool _was_discovering_refs; |
duke@435 | 313 | public: |
duke@435 | 314 | NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) { |
duke@435 | 315 | if (_was_discovering_refs = _rp->discovery_enabled()) { |
duke@435 | 316 | _rp->disable_discovery(); |
duke@435 | 317 | } |
duke@435 | 318 | } |
duke@435 | 319 | |
duke@435 | 320 | ~NoRefDiscovery() { |
duke@435 | 321 | if (_was_discovering_refs) { |
duke@435 | 322 | _rp->enable_discovery(); |
duke@435 | 323 | } |
duke@435 | 324 | } |
duke@435 | 325 | }; |
duke@435 | 326 | |
duke@435 | 327 | |
duke@435 | 328 | // A utility class to temporarily mutate the span of the |
duke@435 | 329 | // given ReferenceProcessor in the scope that contains it. |
duke@435 | 330 | class ReferenceProcessorSpanMutator: StackObj { |
duke@435 | 331 | private: |
duke@435 | 332 | ReferenceProcessor* _rp; |
duke@435 | 333 | MemRegion _saved_span; |
duke@435 | 334 | |
duke@435 | 335 | public: |
duke@435 | 336 | ReferenceProcessorSpanMutator(ReferenceProcessor* rp, |
duke@435 | 337 | MemRegion span): |
duke@435 | 338 | _rp(rp) { |
duke@435 | 339 | _saved_span = _rp->span(); |
duke@435 | 340 | _rp->set_span(span); |
duke@435 | 341 | } |
duke@435 | 342 | |
duke@435 | 343 | ~ReferenceProcessorSpanMutator() { |
duke@435 | 344 | _rp->set_span(_saved_span); |
duke@435 | 345 | } |
duke@435 | 346 | }; |
duke@435 | 347 | |
duke@435 | 348 | // A utility class to temporarily change the MT'ness of |
duke@435 | 349 | // reference discovery for the given ReferenceProcessor |
duke@435 | 350 | // in the scope that contains it. |
duke@435 | 351 | class ReferenceProcessorMTMutator: StackObj { |
duke@435 | 352 | private: |
duke@435 | 353 | ReferenceProcessor* _rp; |
duke@435 | 354 | bool _saved_mt; |
duke@435 | 355 | |
duke@435 | 356 | public: |
duke@435 | 357 | ReferenceProcessorMTMutator(ReferenceProcessor* rp, |
duke@435 | 358 | bool mt): |
duke@435 | 359 | _rp(rp) { |
duke@435 | 360 | _saved_mt = _rp->discovery_is_mt(); |
duke@435 | 361 | _rp->set_mt_discovery(mt); |
duke@435 | 362 | } |
duke@435 | 363 | |
duke@435 | 364 | ~ReferenceProcessorMTMutator() { |
duke@435 | 365 | _rp->set_mt_discovery(_saved_mt); |
duke@435 | 366 | } |
duke@435 | 367 | }; |
duke@435 | 368 | |
duke@435 | 369 | |
duke@435 | 370 | // A utility class to temporarily change the disposition |
duke@435 | 371 | // of the "is_alive_non_header" closure field of the |
duke@435 | 372 | // given ReferenceProcessor in the scope that contains it. |
duke@435 | 373 | class ReferenceProcessorIsAliveMutator: StackObj { |
duke@435 | 374 | private: |
duke@435 | 375 | ReferenceProcessor* _rp; |
duke@435 | 376 | BoolObjectClosure* _saved_cl; |
duke@435 | 377 | |
duke@435 | 378 | public: |
duke@435 | 379 | ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp, |
duke@435 | 380 | BoolObjectClosure* cl): |
duke@435 | 381 | _rp(rp) { |
duke@435 | 382 | _saved_cl = _rp->is_alive_non_header(); |
duke@435 | 383 | _rp->set_is_alive_non_header(cl); |
duke@435 | 384 | } |
duke@435 | 385 | |
duke@435 | 386 | ~ReferenceProcessorIsAliveMutator() { |
duke@435 | 387 | _rp->set_is_alive_non_header(_saved_cl); |
duke@435 | 388 | } |
duke@435 | 389 | }; |
duke@435 | 390 | |
duke@435 | 391 | // A utility class to temporarily change the disposition |
duke@435 | 392 | // of the "discovery_is_atomic" field of the |
duke@435 | 393 | // given ReferenceProcessor in the scope that contains it. |
duke@435 | 394 | class ReferenceProcessorAtomicMutator: StackObj { |
duke@435 | 395 | private: |
duke@435 | 396 | ReferenceProcessor* _rp; |
duke@435 | 397 | bool _saved_atomic_discovery; |
duke@435 | 398 | |
duke@435 | 399 | public: |
duke@435 | 400 | ReferenceProcessorAtomicMutator(ReferenceProcessor* rp, |
duke@435 | 401 | bool atomic): |
duke@435 | 402 | _rp(rp) { |
duke@435 | 403 | _saved_atomic_discovery = _rp->discovery_is_atomic(); |
duke@435 | 404 | _rp->set_atomic_discovery(atomic); |
duke@435 | 405 | } |
duke@435 | 406 | |
duke@435 | 407 | ~ReferenceProcessorAtomicMutator() { |
duke@435 | 408 | _rp->set_atomic_discovery(_saved_atomic_discovery); |
duke@435 | 409 | } |
duke@435 | 410 | }; |
duke@435 | 411 | |
duke@435 | 412 | |
duke@435 | 413 | // A utility class to temporarily change the MT processing |
duke@435 | 414 | // disposition of the given ReferenceProcessor instance |
duke@435 | 415 | // in the scope that contains it. |
duke@435 | 416 | class ReferenceProcessorMTProcMutator: StackObj { |
duke@435 | 417 | private: |
duke@435 | 418 | ReferenceProcessor* _rp; |
duke@435 | 419 | bool _saved_mt; |
duke@435 | 420 | |
duke@435 | 421 | public: |
duke@435 | 422 | ReferenceProcessorMTProcMutator(ReferenceProcessor* rp, |
duke@435 | 423 | bool mt): |
duke@435 | 424 | _rp(rp) { |
duke@435 | 425 | _saved_mt = _rp->processing_is_mt(); |
duke@435 | 426 | _rp->set_mt_processing(mt); |
duke@435 | 427 | } |
duke@435 | 428 | |
duke@435 | 429 | ~ReferenceProcessorMTProcMutator() { |
duke@435 | 430 | _rp->set_mt_processing(_saved_mt); |
duke@435 | 431 | } |
duke@435 | 432 | }; |
duke@435 | 433 | |
duke@435 | 434 | |
duke@435 | 435 | // This class is an interface used to implement task execution for the |
duke@435 | 436 | // reference processing. |
duke@435 | 437 | class AbstractRefProcTaskExecutor { |
duke@435 | 438 | public: |
duke@435 | 439 | |
duke@435 | 440 | // Abstract tasks to execute. |
duke@435 | 441 | class ProcessTask; |
duke@435 | 442 | class EnqueueTask; |
duke@435 | 443 | |
duke@435 | 444 | // Executes a task using worker threads. |
duke@435 | 445 | virtual void execute(ProcessTask& task) = 0; |
duke@435 | 446 | virtual void execute(EnqueueTask& task) = 0; |
duke@435 | 447 | |
duke@435 | 448 | // Switch to single threaded mode. |
duke@435 | 449 | virtual void set_single_threaded_mode() { }; |
duke@435 | 450 | }; |
duke@435 | 451 | |
duke@435 | 452 | // Abstract reference processing task to execute. |
duke@435 | 453 | class AbstractRefProcTaskExecutor::ProcessTask { |
duke@435 | 454 | protected: |
duke@435 | 455 | ProcessTask(ReferenceProcessor& ref_processor, |
duke@435 | 456 | DiscoveredList refs_lists[], |
duke@435 | 457 | bool marks_oops_alive) |
duke@435 | 458 | : _ref_processor(ref_processor), |
duke@435 | 459 | _refs_lists(refs_lists), |
duke@435 | 460 | _marks_oops_alive(marks_oops_alive) |
duke@435 | 461 | { } |
duke@435 | 462 | |
duke@435 | 463 | public: |
duke@435 | 464 | virtual void work(unsigned int work_id, BoolObjectClosure& is_alive, |
duke@435 | 465 | OopClosure& keep_alive, |
duke@435 | 466 | VoidClosure& complete_gc) = 0; |
duke@435 | 467 | |
duke@435 | 468 | // Returns true if a task marks some oops as alive. |
duke@435 | 469 | bool marks_oops_alive() const |
duke@435 | 470 | { return _marks_oops_alive; } |
duke@435 | 471 | |
duke@435 | 472 | protected: |
duke@435 | 473 | ReferenceProcessor& _ref_processor; |
duke@435 | 474 | DiscoveredList* _refs_lists; |
duke@435 | 475 | const bool _marks_oops_alive; |
duke@435 | 476 | }; |
duke@435 | 477 | |
duke@435 | 478 | // Abstract reference processing task to execute. |
duke@435 | 479 | class AbstractRefProcTaskExecutor::EnqueueTask { |
duke@435 | 480 | protected: |
duke@435 | 481 | EnqueueTask(ReferenceProcessor& ref_processor, |
duke@435 | 482 | DiscoveredList refs_lists[], |
coleenp@548 | 483 | HeapWord* pending_list_addr, |
duke@435 | 484 | oop sentinel_ref, |
duke@435 | 485 | int n_queues) |
duke@435 | 486 | : _ref_processor(ref_processor), |
duke@435 | 487 | _refs_lists(refs_lists), |
duke@435 | 488 | _pending_list_addr(pending_list_addr), |
duke@435 | 489 | _sentinel_ref(sentinel_ref), |
duke@435 | 490 | _n_queues(n_queues) |
duke@435 | 491 | { } |
duke@435 | 492 | |
duke@435 | 493 | public: |
duke@435 | 494 | virtual void work(unsigned int work_id) = 0; |
duke@435 | 495 | |
duke@435 | 496 | protected: |
duke@435 | 497 | ReferenceProcessor& _ref_processor; |
duke@435 | 498 | DiscoveredList* _refs_lists; |
coleenp@548 | 499 | HeapWord* _pending_list_addr; |
duke@435 | 500 | oop _sentinel_ref; |
duke@435 | 501 | int _n_queues; |
duke@435 | 502 | }; |