Mon, 26 Jan 2009 12:47:21 -0800
6786503: Overflow list performance can be improved
Summary: Avoid overflow list walk in CMS & ParNew when it is unnecessary. Fix a couple of correctness issues, including a C-heap leak, in ParNew at the intersection of promotion failure, work queue overflow and object array chunking. Add stress testing option and related assertion checking.
Reviewed-by: jmasa
duke@435 | 1 | /* |
xdono@631 | 2 | * Copyright 2001-2008 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 |
ysr@888 | 26 | // of java.lang.Reference objects 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. |
ysr@777 | 57 | // If true, setting "next" field of a discovered refs list requires |
ysr@777 | 58 | // write barrier(s). (Must be true if used in a collector in which |
ysr@777 | 59 | // elements of a discovered list may be moved during discovery: for |
ysr@777 | 60 | // example, a collector like Garbage-First that moves objects during a |
ysr@777 | 61 | // long-term concurrent marking phase that does weak reference |
ysr@777 | 62 | // discovery.) |
ysr@777 | 63 | bool _discovered_list_needs_barrier; |
ysr@777 | 64 | BarrierSet* _bs; // Cached copy of BarrierSet. |
duke@435 | 65 | bool _enqueuing_is_done; // true if all weak references enqueued |
duke@435 | 66 | bool _processing_is_mt; // true during phases when |
duke@435 | 67 | // reference processing is MT. |
duke@435 | 68 | int _next_id; // round-robin counter in |
duke@435 | 69 | // support of work distribution |
duke@435 | 70 | |
duke@435 | 71 | // For collectors that do not keep GC marking information |
duke@435 | 72 | // in the object header, this field holds a closure that |
duke@435 | 73 | // helps the reference processor determine the reachability |
duke@435 | 74 | // of an oop (the field is currently initialized to NULL for |
duke@435 | 75 | // all collectors but the CMS collector). |
duke@435 | 76 | BoolObjectClosure* _is_alive_non_header; |
duke@435 | 77 | |
ysr@888 | 78 | // Soft ref clearing policies |
ysr@888 | 79 | // . the default policy |
ysr@888 | 80 | static ReferencePolicy* _default_soft_ref_policy; |
ysr@888 | 81 | // . the "clear all" policy |
ysr@888 | 82 | static ReferencePolicy* _always_clear_soft_ref_policy; |
ysr@888 | 83 | // . the current policy below is either one of the above |
ysr@888 | 84 | ReferencePolicy* _current_soft_ref_policy; |
ysr@888 | 85 | |
duke@435 | 86 | // The discovered ref lists themselves |
coleenp@548 | 87 | |
coleenp@548 | 88 | // The MT'ness degree of the queues below |
coleenp@548 | 89 | int _num_q; |
coleenp@548 | 90 | // Arrays of lists of oops, one per thread |
coleenp@548 | 91 | DiscoveredList* _discoveredSoftRefs; |
duke@435 | 92 | DiscoveredList* _discoveredWeakRefs; |
duke@435 | 93 | DiscoveredList* _discoveredFinalRefs; |
duke@435 | 94 | DiscoveredList* _discoveredPhantomRefs; |
duke@435 | 95 | |
duke@435 | 96 | public: |
coleenp@548 | 97 | int num_q() { return _num_q; } |
duke@435 | 98 | DiscoveredList* discovered_soft_refs() { return _discoveredSoftRefs; } |
coleenp@548 | 99 | static oop sentinel_ref() { return _sentinelRef; } |
coleenp@548 | 100 | static oop* adr_sentinel_ref() { return &_sentinelRef; } |
ysr@892 | 101 | ReferencePolicy* setup_policy(bool always_clear) { |
ysr@888 | 102 | _current_soft_ref_policy = always_clear ? |
ysr@888 | 103 | _always_clear_soft_ref_policy : _default_soft_ref_policy; |
ysr@892 | 104 | _current_soft_ref_policy->setup(); // snapshot the policy threshold |
ysr@888 | 105 | return _current_soft_ref_policy; |
ysr@888 | 106 | } |
duke@435 | 107 | |
duke@435 | 108 | public: |
duke@435 | 109 | // Process references with a certain reachability level. |
duke@435 | 110 | void process_discovered_reflist(DiscoveredList refs_lists[], |
duke@435 | 111 | ReferencePolicy* policy, |
duke@435 | 112 | bool clear_referent, |
duke@435 | 113 | BoolObjectClosure* is_alive, |
duke@435 | 114 | OopClosure* keep_alive, |
duke@435 | 115 | VoidClosure* complete_gc, |
duke@435 | 116 | AbstractRefProcTaskExecutor* task_executor); |
duke@435 | 117 | |
duke@435 | 118 | void process_phaseJNI(BoolObjectClosure* is_alive, |
duke@435 | 119 | OopClosure* keep_alive, |
duke@435 | 120 | VoidClosure* complete_gc); |
duke@435 | 121 | |
duke@435 | 122 | // Work methods used by the method process_discovered_reflist |
duke@435 | 123 | // Phase1: keep alive all those referents that are otherwise |
duke@435 | 124 | // dead but which must be kept alive by policy (and their closure). |
coleenp@548 | 125 | void process_phase1(DiscoveredList& refs_list, |
duke@435 | 126 | ReferencePolicy* policy, |
duke@435 | 127 | BoolObjectClosure* is_alive, |
duke@435 | 128 | OopClosure* keep_alive, |
duke@435 | 129 | VoidClosure* complete_gc); |
duke@435 | 130 | // Phase2: remove all those references whose referents are |
duke@435 | 131 | // reachable. |
coleenp@548 | 132 | inline void process_phase2(DiscoveredList& refs_list, |
duke@435 | 133 | BoolObjectClosure* is_alive, |
duke@435 | 134 | OopClosure* keep_alive, |
duke@435 | 135 | VoidClosure* complete_gc) { |
duke@435 | 136 | if (discovery_is_atomic()) { |
duke@435 | 137 | // complete_gc is ignored in this case for this phase |
coleenp@548 | 138 | pp2_work(refs_list, is_alive, keep_alive); |
duke@435 | 139 | } else { |
duke@435 | 140 | assert(complete_gc != NULL, "Error"); |
coleenp@548 | 141 | pp2_work_concurrent_discovery(refs_list, is_alive, |
duke@435 | 142 | keep_alive, complete_gc); |
duke@435 | 143 | } |
duke@435 | 144 | } |
duke@435 | 145 | // Work methods in support of process_phase2 |
coleenp@548 | 146 | void pp2_work(DiscoveredList& refs_list, |
duke@435 | 147 | BoolObjectClosure* is_alive, |
duke@435 | 148 | OopClosure* keep_alive); |
duke@435 | 149 | void pp2_work_concurrent_discovery( |
coleenp@548 | 150 | DiscoveredList& refs_list, |
duke@435 | 151 | BoolObjectClosure* is_alive, |
duke@435 | 152 | OopClosure* keep_alive, |
duke@435 | 153 | VoidClosure* complete_gc); |
duke@435 | 154 | // Phase3: process the referents by either clearing them |
duke@435 | 155 | // or keeping them alive (and their closure) |
coleenp@548 | 156 | void process_phase3(DiscoveredList& refs_list, |
duke@435 | 157 | bool clear_referent, |
duke@435 | 158 | BoolObjectClosure* is_alive, |
duke@435 | 159 | OopClosure* keep_alive, |
duke@435 | 160 | VoidClosure* complete_gc); |
duke@435 | 161 | |
duke@435 | 162 | // Enqueue references with a certain reachability level |
coleenp@548 | 163 | void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr); |
duke@435 | 164 | |
duke@435 | 165 | // "Preclean" all the discovered reference lists |
duke@435 | 166 | // by removing references with strongly reachable referents. |
duke@435 | 167 | // The first argument is a predicate on an oop that indicates |
duke@435 | 168 | // its (strong) reachability and the second is a closure that |
duke@435 | 169 | // may be used to incrementalize or abort the precleaning process. |
duke@435 | 170 | // The caller is responsible for taking care of potential |
duke@435 | 171 | // interference with concurrent operations on these lists |
duke@435 | 172 | // (or predicates involved) by other threads. Currently |
duke@435 | 173 | // only used by the CMS collector. |
duke@435 | 174 | void preclean_discovered_references(BoolObjectClosure* is_alive, |
duke@435 | 175 | OopClosure* keep_alive, |
duke@435 | 176 | VoidClosure* complete_gc, |
duke@435 | 177 | YieldClosure* yield); |
duke@435 | 178 | |
duke@435 | 179 | // Delete entries in the discovered lists that have |
duke@435 | 180 | // either a null referent or are not active. Such |
duke@435 | 181 | // Reference objects can result from the clearing |
duke@435 | 182 | // or enqueueing of Reference objects concurrent |
duke@435 | 183 | // with their discovery by a (concurrent) collector. |
duke@435 | 184 | // For a definition of "active" see java.lang.ref.Reference; |
duke@435 | 185 | // Refs are born active, become inactive when enqueued, |
duke@435 | 186 | // and never become active again. The state of being |
duke@435 | 187 | // active is encoded as follows: A Ref is active |
duke@435 | 188 | // if and only if its "next" field is NULL. |
duke@435 | 189 | void clean_up_discovered_references(); |
duke@435 | 190 | void clean_up_discovered_reflist(DiscoveredList& refs_list); |
duke@435 | 191 | |
duke@435 | 192 | // Returns the name of the discovered reference list |
duke@435 | 193 | // occupying the i / _num_q slot. |
duke@435 | 194 | const char* list_name(int i); |
duke@435 | 195 | |
coleenp@548 | 196 | void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor); |
coleenp@548 | 197 | |
duke@435 | 198 | protected: |
duke@435 | 199 | // "Preclean" the given discovered reference list |
duke@435 | 200 | // by removing references with strongly reachable referents. |
duke@435 | 201 | // Currently used in support of CMS only. |
duke@435 | 202 | void preclean_discovered_reflist(DiscoveredList& refs_list, |
duke@435 | 203 | BoolObjectClosure* is_alive, |
duke@435 | 204 | OopClosure* keep_alive, |
duke@435 | 205 | VoidClosure* complete_gc, |
duke@435 | 206 | YieldClosure* yield); |
duke@435 | 207 | |
duke@435 | 208 | int next_id() { |
duke@435 | 209 | int id = _next_id; |
duke@435 | 210 | if (++_next_id == _num_q) { |
duke@435 | 211 | _next_id = 0; |
duke@435 | 212 | } |
duke@435 | 213 | return id; |
duke@435 | 214 | } |
duke@435 | 215 | DiscoveredList* get_discovered_list(ReferenceType rt); |
duke@435 | 216 | inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj, |
coleenp@548 | 217 | HeapWord* discovered_addr); |
duke@435 | 218 | void verify_ok_to_handle_reflists() PRODUCT_RETURN; |
duke@435 | 219 | |
duke@435 | 220 | void abandon_partial_discovered_list(DiscoveredList& refs_list); |
duke@435 | 221 | |
duke@435 | 222 | // Calculate the number of jni handles. |
duke@435 | 223 | unsigned int count_jni_refs(); |
duke@435 | 224 | |
duke@435 | 225 | // Balances reference queues. |
duke@435 | 226 | void balance_queues(DiscoveredList ref_lists[]); |
duke@435 | 227 | |
duke@435 | 228 | // Update (advance) the soft ref master clock field. |
duke@435 | 229 | void update_soft_ref_master_clock(); |
duke@435 | 230 | |
duke@435 | 231 | public: |
duke@435 | 232 | // constructor |
duke@435 | 233 | ReferenceProcessor(): |
duke@435 | 234 | _span((HeapWord*)NULL, (HeapWord*)NULL), |
duke@435 | 235 | _discoveredSoftRefs(NULL), _discoveredWeakRefs(NULL), |
duke@435 | 236 | _discoveredFinalRefs(NULL), _discoveredPhantomRefs(NULL), |
duke@435 | 237 | _discovering_refs(false), |
duke@435 | 238 | _discovery_is_atomic(true), |
duke@435 | 239 | _enqueuing_is_done(false), |
duke@435 | 240 | _discovery_is_mt(false), |
ysr@777 | 241 | _discovered_list_needs_barrier(false), |
ysr@777 | 242 | _bs(NULL), |
duke@435 | 243 | _is_alive_non_header(NULL), |
duke@435 | 244 | _num_q(0), |
duke@435 | 245 | _processing_is_mt(false), |
duke@435 | 246 | _next_id(0) |
duke@435 | 247 | {} |
duke@435 | 248 | |
duke@435 | 249 | ReferenceProcessor(MemRegion span, bool atomic_discovery, |
ysr@777 | 250 | bool mt_discovery, |
ysr@777 | 251 | int mt_degree = 1, |
ysr@777 | 252 | bool mt_processing = false, |
ysr@777 | 253 | bool discovered_list_needs_barrier = false); |
duke@435 | 254 | |
duke@435 | 255 | // Allocates and initializes a reference processor. |
duke@435 | 256 | static ReferenceProcessor* create_ref_processor( |
duke@435 | 257 | MemRegion span, |
duke@435 | 258 | bool atomic_discovery, |
duke@435 | 259 | bool mt_discovery, |
duke@435 | 260 | BoolObjectClosure* is_alive_non_header = NULL, |
duke@435 | 261 | int parallel_gc_threads = 1, |
ysr@777 | 262 | bool mt_processing = false, |
ysr@777 | 263 | bool discovered_list_needs_barrier = false); |
duke@435 | 264 | // RefDiscoveryPolicy values |
duke@435 | 265 | enum { |
duke@435 | 266 | ReferenceBasedDiscovery = 0, |
duke@435 | 267 | ReferentBasedDiscovery = 1 |
duke@435 | 268 | }; |
duke@435 | 269 | |
duke@435 | 270 | static void init_statics(); |
duke@435 | 271 | |
duke@435 | 272 | public: |
duke@435 | 273 | // get and set "is_alive_non_header" field |
duke@435 | 274 | BoolObjectClosure* is_alive_non_header() { |
duke@435 | 275 | return _is_alive_non_header; |
duke@435 | 276 | } |
duke@435 | 277 | void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) { |
duke@435 | 278 | _is_alive_non_header = is_alive_non_header; |
duke@435 | 279 | } |
duke@435 | 280 | |
duke@435 | 281 | // get and set span |
duke@435 | 282 | MemRegion span() { return _span; } |
duke@435 | 283 | void set_span(MemRegion span) { _span = span; } |
duke@435 | 284 | |
duke@435 | 285 | // start and stop weak ref discovery |
duke@435 | 286 | void enable_discovery() { _discovering_refs = true; } |
duke@435 | 287 | void disable_discovery() { _discovering_refs = false; } |
duke@435 | 288 | bool discovery_enabled() { return _discovering_refs; } |
duke@435 | 289 | |
duke@435 | 290 | // whether discovery is atomic wrt other collectors |
duke@435 | 291 | bool discovery_is_atomic() const { return _discovery_is_atomic; } |
duke@435 | 292 | void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; } |
duke@435 | 293 | |
duke@435 | 294 | // whether discovery is done by multiple threads same-old-timeously |
duke@435 | 295 | bool discovery_is_mt() const { return _discovery_is_mt; } |
duke@435 | 296 | void set_mt_discovery(bool mt) { _discovery_is_mt = mt; } |
duke@435 | 297 | |
duke@435 | 298 | // Whether we are in a phase when _processing_ is MT. |
duke@435 | 299 | bool processing_is_mt() const { return _processing_is_mt; } |
duke@435 | 300 | void set_mt_processing(bool mt) { _processing_is_mt = mt; } |
duke@435 | 301 | |
duke@435 | 302 | // whether all enqueuing of weak references is complete |
duke@435 | 303 | bool enqueuing_is_done() { return _enqueuing_is_done; } |
duke@435 | 304 | void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; } |
duke@435 | 305 | |
duke@435 | 306 | // iterate over oops |
duke@435 | 307 | void weak_oops_do(OopClosure* f); // weak roots |
duke@435 | 308 | static void oops_do(OopClosure* f); // strong root(s) |
duke@435 | 309 | |
duke@435 | 310 | // Discover a Reference object, using appropriate discovery criteria |
duke@435 | 311 | bool discover_reference(oop obj, ReferenceType rt); |
duke@435 | 312 | |
duke@435 | 313 | // Process references found during GC (called by the garbage collector) |
ysr@888 | 314 | void process_discovered_references(BoolObjectClosure* is_alive, |
duke@435 | 315 | OopClosure* keep_alive, |
duke@435 | 316 | VoidClosure* complete_gc, |
duke@435 | 317 | AbstractRefProcTaskExecutor* task_executor); |
duke@435 | 318 | |
duke@435 | 319 | public: |
duke@435 | 320 | // Enqueue references at end of GC (called by the garbage collector) |
duke@435 | 321 | bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL); |
duke@435 | 322 | |
ysr@777 | 323 | // If a discovery is in process that is being superceded, abandon it: all |
ysr@777 | 324 | // the discovered lists will be empty, and all the objects on them will |
ysr@777 | 325 | // have NULL discovered fields. Must be called only at a safepoint. |
ysr@777 | 326 | void abandon_partial_discovery(); |
ysr@777 | 327 | |
duke@435 | 328 | // debugging |
duke@435 | 329 | void verify_no_references_recorded() PRODUCT_RETURN; |
duke@435 | 330 | static void verify(); |
duke@435 | 331 | |
duke@435 | 332 | // clear the discovered lists (unlinking each entry). |
duke@435 | 333 | void clear_discovered_references() PRODUCT_RETURN; |
duke@435 | 334 | }; |
duke@435 | 335 | |
duke@435 | 336 | // A utility class to disable reference discovery in |
duke@435 | 337 | // the scope which contains it, for given ReferenceProcessor. |
duke@435 | 338 | class NoRefDiscovery: StackObj { |
duke@435 | 339 | private: |
duke@435 | 340 | ReferenceProcessor* _rp; |
duke@435 | 341 | bool _was_discovering_refs; |
duke@435 | 342 | public: |
duke@435 | 343 | NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) { |
duke@435 | 344 | if (_was_discovering_refs = _rp->discovery_enabled()) { |
duke@435 | 345 | _rp->disable_discovery(); |
duke@435 | 346 | } |
duke@435 | 347 | } |
duke@435 | 348 | |
duke@435 | 349 | ~NoRefDiscovery() { |
duke@435 | 350 | if (_was_discovering_refs) { |
duke@435 | 351 | _rp->enable_discovery(); |
duke@435 | 352 | } |
duke@435 | 353 | } |
duke@435 | 354 | }; |
duke@435 | 355 | |
duke@435 | 356 | |
duke@435 | 357 | // A utility class to temporarily mutate the span of the |
duke@435 | 358 | // given ReferenceProcessor in the scope that contains it. |
duke@435 | 359 | class ReferenceProcessorSpanMutator: StackObj { |
duke@435 | 360 | private: |
duke@435 | 361 | ReferenceProcessor* _rp; |
duke@435 | 362 | MemRegion _saved_span; |
duke@435 | 363 | |
duke@435 | 364 | public: |
duke@435 | 365 | ReferenceProcessorSpanMutator(ReferenceProcessor* rp, |
duke@435 | 366 | MemRegion span): |
duke@435 | 367 | _rp(rp) { |
duke@435 | 368 | _saved_span = _rp->span(); |
duke@435 | 369 | _rp->set_span(span); |
duke@435 | 370 | } |
duke@435 | 371 | |
duke@435 | 372 | ~ReferenceProcessorSpanMutator() { |
duke@435 | 373 | _rp->set_span(_saved_span); |
duke@435 | 374 | } |
duke@435 | 375 | }; |
duke@435 | 376 | |
duke@435 | 377 | // A utility class to temporarily change the MT'ness of |
duke@435 | 378 | // reference discovery for the given ReferenceProcessor |
duke@435 | 379 | // in the scope that contains it. |
duke@435 | 380 | class ReferenceProcessorMTMutator: StackObj { |
duke@435 | 381 | private: |
duke@435 | 382 | ReferenceProcessor* _rp; |
duke@435 | 383 | bool _saved_mt; |
duke@435 | 384 | |
duke@435 | 385 | public: |
duke@435 | 386 | ReferenceProcessorMTMutator(ReferenceProcessor* rp, |
duke@435 | 387 | bool mt): |
duke@435 | 388 | _rp(rp) { |
duke@435 | 389 | _saved_mt = _rp->discovery_is_mt(); |
duke@435 | 390 | _rp->set_mt_discovery(mt); |
duke@435 | 391 | } |
duke@435 | 392 | |
duke@435 | 393 | ~ReferenceProcessorMTMutator() { |
duke@435 | 394 | _rp->set_mt_discovery(_saved_mt); |
duke@435 | 395 | } |
duke@435 | 396 | }; |
duke@435 | 397 | |
duke@435 | 398 | |
duke@435 | 399 | // A utility class to temporarily change the disposition |
duke@435 | 400 | // of the "is_alive_non_header" closure field of the |
duke@435 | 401 | // given ReferenceProcessor in the scope that contains it. |
duke@435 | 402 | class ReferenceProcessorIsAliveMutator: StackObj { |
duke@435 | 403 | private: |
duke@435 | 404 | ReferenceProcessor* _rp; |
duke@435 | 405 | BoolObjectClosure* _saved_cl; |
duke@435 | 406 | |
duke@435 | 407 | public: |
duke@435 | 408 | ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp, |
duke@435 | 409 | BoolObjectClosure* cl): |
duke@435 | 410 | _rp(rp) { |
duke@435 | 411 | _saved_cl = _rp->is_alive_non_header(); |
duke@435 | 412 | _rp->set_is_alive_non_header(cl); |
duke@435 | 413 | } |
duke@435 | 414 | |
duke@435 | 415 | ~ReferenceProcessorIsAliveMutator() { |
duke@435 | 416 | _rp->set_is_alive_non_header(_saved_cl); |
duke@435 | 417 | } |
duke@435 | 418 | }; |
duke@435 | 419 | |
duke@435 | 420 | // A utility class to temporarily change the disposition |
duke@435 | 421 | // of the "discovery_is_atomic" field of the |
duke@435 | 422 | // given ReferenceProcessor in the scope that contains it. |
duke@435 | 423 | class ReferenceProcessorAtomicMutator: StackObj { |
duke@435 | 424 | private: |
duke@435 | 425 | ReferenceProcessor* _rp; |
duke@435 | 426 | bool _saved_atomic_discovery; |
duke@435 | 427 | |
duke@435 | 428 | public: |
duke@435 | 429 | ReferenceProcessorAtomicMutator(ReferenceProcessor* rp, |
duke@435 | 430 | bool atomic): |
duke@435 | 431 | _rp(rp) { |
duke@435 | 432 | _saved_atomic_discovery = _rp->discovery_is_atomic(); |
duke@435 | 433 | _rp->set_atomic_discovery(atomic); |
duke@435 | 434 | } |
duke@435 | 435 | |
duke@435 | 436 | ~ReferenceProcessorAtomicMutator() { |
duke@435 | 437 | _rp->set_atomic_discovery(_saved_atomic_discovery); |
duke@435 | 438 | } |
duke@435 | 439 | }; |
duke@435 | 440 | |
duke@435 | 441 | |
duke@435 | 442 | // A utility class to temporarily change the MT processing |
duke@435 | 443 | // disposition of the given ReferenceProcessor instance |
duke@435 | 444 | // in the scope that contains it. |
duke@435 | 445 | class ReferenceProcessorMTProcMutator: StackObj { |
duke@435 | 446 | private: |
duke@435 | 447 | ReferenceProcessor* _rp; |
duke@435 | 448 | bool _saved_mt; |
duke@435 | 449 | |
duke@435 | 450 | public: |
duke@435 | 451 | ReferenceProcessorMTProcMutator(ReferenceProcessor* rp, |
duke@435 | 452 | bool mt): |
duke@435 | 453 | _rp(rp) { |
duke@435 | 454 | _saved_mt = _rp->processing_is_mt(); |
duke@435 | 455 | _rp->set_mt_processing(mt); |
duke@435 | 456 | } |
duke@435 | 457 | |
duke@435 | 458 | ~ReferenceProcessorMTProcMutator() { |
duke@435 | 459 | _rp->set_mt_processing(_saved_mt); |
duke@435 | 460 | } |
duke@435 | 461 | }; |
duke@435 | 462 | |
duke@435 | 463 | |
duke@435 | 464 | // This class is an interface used to implement task execution for the |
duke@435 | 465 | // reference processing. |
duke@435 | 466 | class AbstractRefProcTaskExecutor { |
duke@435 | 467 | public: |
duke@435 | 468 | |
duke@435 | 469 | // Abstract tasks to execute. |
duke@435 | 470 | class ProcessTask; |
duke@435 | 471 | class EnqueueTask; |
duke@435 | 472 | |
duke@435 | 473 | // Executes a task using worker threads. |
duke@435 | 474 | virtual void execute(ProcessTask& task) = 0; |
duke@435 | 475 | virtual void execute(EnqueueTask& task) = 0; |
duke@435 | 476 | |
duke@435 | 477 | // Switch to single threaded mode. |
duke@435 | 478 | virtual void set_single_threaded_mode() { }; |
duke@435 | 479 | }; |
duke@435 | 480 | |
duke@435 | 481 | // Abstract reference processing task to execute. |
duke@435 | 482 | class AbstractRefProcTaskExecutor::ProcessTask { |
duke@435 | 483 | protected: |
duke@435 | 484 | ProcessTask(ReferenceProcessor& ref_processor, |
duke@435 | 485 | DiscoveredList refs_lists[], |
duke@435 | 486 | bool marks_oops_alive) |
duke@435 | 487 | : _ref_processor(ref_processor), |
duke@435 | 488 | _refs_lists(refs_lists), |
duke@435 | 489 | _marks_oops_alive(marks_oops_alive) |
duke@435 | 490 | { } |
duke@435 | 491 | |
duke@435 | 492 | public: |
duke@435 | 493 | virtual void work(unsigned int work_id, BoolObjectClosure& is_alive, |
duke@435 | 494 | OopClosure& keep_alive, |
duke@435 | 495 | VoidClosure& complete_gc) = 0; |
duke@435 | 496 | |
duke@435 | 497 | // Returns true if a task marks some oops as alive. |
duke@435 | 498 | bool marks_oops_alive() const |
duke@435 | 499 | { return _marks_oops_alive; } |
duke@435 | 500 | |
duke@435 | 501 | protected: |
duke@435 | 502 | ReferenceProcessor& _ref_processor; |
duke@435 | 503 | DiscoveredList* _refs_lists; |
duke@435 | 504 | const bool _marks_oops_alive; |
duke@435 | 505 | }; |
duke@435 | 506 | |
duke@435 | 507 | // Abstract reference processing task to execute. |
duke@435 | 508 | class AbstractRefProcTaskExecutor::EnqueueTask { |
duke@435 | 509 | protected: |
duke@435 | 510 | EnqueueTask(ReferenceProcessor& ref_processor, |
duke@435 | 511 | DiscoveredList refs_lists[], |
coleenp@548 | 512 | HeapWord* pending_list_addr, |
duke@435 | 513 | oop sentinel_ref, |
duke@435 | 514 | int n_queues) |
duke@435 | 515 | : _ref_processor(ref_processor), |
duke@435 | 516 | _refs_lists(refs_lists), |
duke@435 | 517 | _pending_list_addr(pending_list_addr), |
duke@435 | 518 | _sentinel_ref(sentinel_ref), |
duke@435 | 519 | _n_queues(n_queues) |
duke@435 | 520 | { } |
duke@435 | 521 | |
duke@435 | 522 | public: |
duke@435 | 523 | virtual void work(unsigned int work_id) = 0; |
duke@435 | 524 | |
duke@435 | 525 | protected: |
duke@435 | 526 | ReferenceProcessor& _ref_processor; |
duke@435 | 527 | DiscoveredList* _refs_lists; |
coleenp@548 | 528 | HeapWord* _pending_list_addr; |
duke@435 | 529 | oop _sentinel_ref; |
duke@435 | 530 | int _n_queues; |
duke@435 | 531 | }; |