duke@435: /* coleenp@4037: * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. duke@435: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. duke@435: * duke@435: * This code is free software; you can redistribute it and/or modify it duke@435: * under the terms of the GNU General Public License version 2 only, as duke@435: * published by the Free Software Foundation. duke@435: * duke@435: * This code is distributed in the hope that it will be useful, but WITHOUT duke@435: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or duke@435: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License duke@435: * version 2 for more details (a copy is included in the LICENSE file that duke@435: * accompanied this code). duke@435: * duke@435: * You should have received a copy of the GNU General Public License version duke@435: * 2 along with this work; if not, write to the Free Software Foundation, duke@435: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. duke@435: * trims@1907: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA trims@1907: * or visit www.oracle.com if you need additional information or have any trims@1907: * questions. duke@435: * duke@435: */ duke@435: stefank@2314: #ifndef SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP stefank@2314: #define SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP stefank@2314: stefank@2314: #include "memory/referencePolicy.hpp" stefank@2314: #include "oops/instanceRefKlass.hpp" stefank@2314: duke@435: // ReferenceProcessor class encapsulates the per-"collector" processing ysr@888: // of java.lang.Reference objects for GC. The interface is useful for supporting duke@435: // a generational abstraction, in particular when there are multiple duke@435: // generations that are being independently collected -- possibly duke@435: // concurrently and/or incrementally. Note, however, that the duke@435: // ReferenceProcessor class abstracts away from a generational setting duke@435: // by using only a heap interval (called "span" below), thus allowing duke@435: // its use in a straightforward manner in a general, non-generational duke@435: // setting. duke@435: // duke@435: // The basic idea is that each ReferenceProcessor object concerns duke@435: // itself with ("weak") reference processing in a specific "span" duke@435: // of the heap of interest to a specific collector. Currently, duke@435: // the span is a convex interval of the heap, but, efficiency duke@435: // apart, there seems to be no reason it couldn't be extended duke@435: // (with appropriate modifications) to any "non-convex interval". duke@435: duke@435: // forward references duke@435: class ReferencePolicy; duke@435: class AbstractRefProcTaskExecutor; johnc@3175: johnc@3175: // List of discovered references. johnc@3175: class DiscoveredList { johnc@3175: public: johnc@3175: DiscoveredList() : _len(0), _compressed_head(0), _oop_head(NULL) { } johnc@3175: oop head() const { johnc@3175: return UseCompressedOops ? oopDesc::decode_heap_oop(_compressed_head) : johnc@3175: _oop_head; johnc@3175: } johnc@3175: HeapWord* adr_head() { johnc@3175: return UseCompressedOops ? (HeapWord*)&_compressed_head : johnc@3175: (HeapWord*)&_oop_head; johnc@3175: } johnc@3175: void set_head(oop o) { johnc@3175: if (UseCompressedOops) { johnc@3175: // Must compress the head ptr. johnc@3175: _compressed_head = oopDesc::encode_heap_oop(o); johnc@3175: } else { johnc@3175: _oop_head = o; johnc@3175: } johnc@3175: } johnc@3175: bool is_empty() const { return head() == NULL; } johnc@3175: size_t length() { return _len; } johnc@3175: void set_length(size_t len) { _len = len; } johnc@3175: void inc_length(size_t inc) { _len += inc; assert(_len > 0, "Error"); } johnc@3175: void dec_length(size_t dec) { _len -= dec; } johnc@3175: private: johnc@3175: // Set value depending on UseCompressedOops. This could be a template class johnc@3175: // but then we have to fix all the instantiations and declarations that use this class. johnc@3175: oop _oop_head; johnc@3175: narrowOop _compressed_head; johnc@3175: size_t _len; johnc@3175: }; johnc@3175: johnc@3175: // Iterator for the list of discovered references. johnc@3175: class DiscoveredListIterator { johnc@3175: private: johnc@3175: DiscoveredList& _refs_list; johnc@3175: HeapWord* _prev_next; johnc@3175: oop _prev; johnc@3175: oop _ref; johnc@3175: HeapWord* _discovered_addr; johnc@3175: oop _next; johnc@3175: HeapWord* _referent_addr; johnc@3175: oop _referent; johnc@3175: OopClosure* _keep_alive; johnc@3175: BoolObjectClosure* _is_alive; johnc@3175: johnc@3175: DEBUG_ONLY( johnc@3175: oop _first_seen; // cyclic linked list check johnc@3175: ) johnc@3175: johnc@3175: NOT_PRODUCT( johnc@3175: size_t _processed; johnc@3175: size_t _removed; johnc@3175: ) johnc@3175: johnc@3175: public: johnc@3175: inline DiscoveredListIterator(DiscoveredList& refs_list, johnc@3175: OopClosure* keep_alive, johnc@3175: BoolObjectClosure* is_alive): johnc@3175: _refs_list(refs_list), johnc@3175: _prev_next(refs_list.adr_head()), johnc@3175: _prev(NULL), johnc@3175: _ref(refs_list.head()), johnc@3175: #ifdef ASSERT johnc@3175: _first_seen(refs_list.head()), johnc@3175: #endif johnc@3175: #ifndef PRODUCT johnc@3175: _processed(0), johnc@3175: _removed(0), johnc@3175: #endif johnc@3175: _next(NULL), johnc@3175: _keep_alive(keep_alive), johnc@3175: _is_alive(is_alive) johnc@3175: { } johnc@3175: johnc@3175: // End Of List. johnc@3175: inline bool has_next() const { return _ref != NULL; } johnc@3175: johnc@3175: // Get oop to the Reference object. johnc@3175: inline oop obj() const { return _ref; } johnc@3175: johnc@3175: // Get oop to the referent object. johnc@3175: inline oop referent() const { return _referent; } johnc@3175: johnc@3175: // Returns true if referent is alive. johnc@3175: inline bool is_referent_alive() const { johnc@3175: return _is_alive->do_object_b(_referent); johnc@3175: } johnc@3175: johnc@3175: // Loads data for the current reference. johnc@3175: // The "allow_null_referent" argument tells us to allow for the possibility johnc@3175: // of a NULL referent in the discovered Reference object. This typically johnc@3175: // happens in the case of concurrent collectors that may have done the johnc@3175: // discovery concurrently, or interleaved, with mutator execution. johnc@3175: void load_ptrs(DEBUG_ONLY(bool allow_null_referent)); johnc@3175: johnc@3175: // Move to the next discovered reference. johnc@3175: inline void next() { johnc@3175: _prev_next = _discovered_addr; johnc@3175: _prev = _ref; johnc@3175: move_to_next(); johnc@3175: } johnc@3175: johnc@3175: // Remove the current reference from the list johnc@3175: void remove(); johnc@3175: johnc@3175: // Make the Reference object active again. johnc@3175: void make_active(); johnc@3175: johnc@3175: // Make the referent alive. johnc@3175: inline void make_referent_alive() { johnc@3175: if (UseCompressedOops) { johnc@3175: _keep_alive->do_oop((narrowOop*)_referent_addr); johnc@3175: } else { johnc@3175: _keep_alive->do_oop((oop*)_referent_addr); johnc@3175: } johnc@3175: } johnc@3175: johnc@3175: // Update the discovered field. johnc@3175: inline void update_discovered() { johnc@3175: // First _prev_next ref actually points into DiscoveredList (gross). johnc@3175: if (UseCompressedOops) { johnc@3175: if (!oopDesc::is_null(*(narrowOop*)_prev_next)) { johnc@3175: _keep_alive->do_oop((narrowOop*)_prev_next); johnc@3175: } johnc@3175: } else { johnc@3175: if (!oopDesc::is_null(*(oop*)_prev_next)) { johnc@3175: _keep_alive->do_oop((oop*)_prev_next); johnc@3175: } johnc@3175: } johnc@3175: } johnc@3175: johnc@3175: // NULL out referent pointer. johnc@3175: void clear_referent(); johnc@3175: johnc@3175: // Statistics johnc@3175: NOT_PRODUCT( johnc@3175: inline size_t processed() const { return _processed; } johnc@3175: inline size_t removed() const { return _removed; } johnc@3175: ) johnc@3175: johnc@3175: inline void move_to_next() { johnc@3175: if (_ref == _next) { johnc@3175: // End of the list. johnc@3175: _ref = NULL; johnc@3175: } else { johnc@3175: _ref = _next; johnc@3175: } johnc@3175: assert(_ref != _first_seen, "cyclic ref_list found"); johnc@3175: NOT_PRODUCT(_processed++); johnc@3175: } johnc@3175: }; duke@435: zgu@3900: class ReferenceProcessor : public CHeapObj { duke@435: protected: ysr@3117: // Compatibility with pre-4965777 JDK's ysr@3117: static bool _pending_list_uses_discovered_field; johnc@3175: johnc@3188: // The SoftReference master timestamp clock johnc@3188: static jlong _soft_ref_timestamp_clock; johnc@3188: johnc@3175: MemRegion _span; // (right-open) interval of heap johnc@3175: // subject to wkref discovery johnc@3175: johnc@3175: bool _discovering_refs; // true when discovery enabled johnc@3175: bool _discovery_is_atomic; // if discovery is atomic wrt johnc@3175: // other collectors in configuration johnc@3175: bool _discovery_is_mt; // true if reference discovery is MT. johnc@3175: ysr@777: // If true, setting "next" field of a discovered refs list requires ysr@777: // write barrier(s). (Must be true if used in a collector in which ysr@777: // elements of a discovered list may be moved during discovery: for ysr@777: // example, a collector like Garbage-First that moves objects during a ysr@777: // long-term concurrent marking phase that does weak reference ysr@777: // discovery.) ysr@777: bool _discovered_list_needs_barrier; duke@435: johnc@3175: BarrierSet* _bs; // Cached copy of BarrierSet. johnc@3175: bool _enqueuing_is_done; // true if all weak references enqueued johnc@3175: bool _processing_is_mt; // true during phases when johnc@3175: // reference processing is MT. jmasa@3357: uint _next_id; // round-robin mod _num_q counter in johnc@3175: // support of work distribution johnc@3175: johnc@3175: // For collectors that do not keep GC liveness information duke@435: // in the object header, this field holds a closure that duke@435: // helps the reference processor determine the reachability johnc@3175: // of an oop. It is currently initialized to NULL for all johnc@3175: // collectors except for CMS and G1. duke@435: BoolObjectClosure* _is_alive_non_header; duke@435: ysr@888: // Soft ref clearing policies ysr@888: // . the default policy ysr@888: static ReferencePolicy* _default_soft_ref_policy; ysr@888: // . the "clear all" policy ysr@888: static ReferencePolicy* _always_clear_soft_ref_policy; ysr@888: // . the current policy below is either one of the above ysr@888: ReferencePolicy* _current_soft_ref_policy; ysr@888: duke@435: // The discovered ref lists themselves coleenp@548: jmasa@2188: // The active MT'ness degree of the queues below jmasa@3357: uint _num_q; jmasa@2188: // The maximum MT'ness degree of the queues below jmasa@3357: uint _max_num_q; johnc@3210: johnc@3210: // Master array of discovered oops johnc@3210: DiscoveredList* _discovered_refs; johnc@3210: johnc@3210: // Arrays of lists of oops, one per thread (pointers into master array above) coleenp@548: DiscoveredList* _discoveredSoftRefs; duke@435: DiscoveredList* _discoveredWeakRefs; duke@435: DiscoveredList* _discoveredFinalRefs; duke@435: DiscoveredList* _discoveredPhantomRefs; duke@435: duke@435: public: johnc@3175: static int number_of_subclasses_of_ref() { return (REF_PHANTOM - REF_OTHER); } johnc@3175: jmasa@3357: uint num_q() { return _num_q; } jmasa@3357: uint max_num_q() { return _max_num_q; } jmasa@3357: void set_active_mt_degree(uint v) { _num_q = v; } johnc@3210: johnc@3210: DiscoveredList* discovered_refs() { return _discovered_refs; } johnc@3175: ysr@892: ReferencePolicy* setup_policy(bool always_clear) { ysr@888: _current_soft_ref_policy = always_clear ? ysr@888: _always_clear_soft_ref_policy : _default_soft_ref_policy; ysr@892: _current_soft_ref_policy->setup(); // snapshot the policy threshold ysr@888: return _current_soft_ref_policy; ysr@888: } duke@435: duke@435: // Process references with a certain reachability level. duke@435: void process_discovered_reflist(DiscoveredList refs_lists[], duke@435: ReferencePolicy* policy, duke@435: bool clear_referent, duke@435: BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive, duke@435: VoidClosure* complete_gc, duke@435: AbstractRefProcTaskExecutor* task_executor); duke@435: duke@435: void process_phaseJNI(BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive, duke@435: VoidClosure* complete_gc); duke@435: duke@435: // Work methods used by the method process_discovered_reflist duke@435: // Phase1: keep alive all those referents that are otherwise duke@435: // dead but which must be kept alive by policy (and their closure). coleenp@548: void process_phase1(DiscoveredList& refs_list, duke@435: ReferencePolicy* policy, duke@435: BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive, duke@435: VoidClosure* complete_gc); duke@435: // Phase2: remove all those references whose referents are duke@435: // reachable. coleenp@548: inline void process_phase2(DiscoveredList& refs_list, duke@435: BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive, duke@435: VoidClosure* complete_gc) { duke@435: if (discovery_is_atomic()) { duke@435: // complete_gc is ignored in this case for this phase coleenp@548: pp2_work(refs_list, is_alive, keep_alive); duke@435: } else { duke@435: assert(complete_gc != NULL, "Error"); coleenp@548: pp2_work_concurrent_discovery(refs_list, is_alive, duke@435: keep_alive, complete_gc); duke@435: } duke@435: } duke@435: // Work methods in support of process_phase2 coleenp@548: void pp2_work(DiscoveredList& refs_list, duke@435: BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive); duke@435: void pp2_work_concurrent_discovery( coleenp@548: DiscoveredList& refs_list, duke@435: BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive, duke@435: VoidClosure* complete_gc); duke@435: // Phase3: process the referents by either clearing them duke@435: // or keeping them alive (and their closure) coleenp@548: void process_phase3(DiscoveredList& refs_list, duke@435: bool clear_referent, duke@435: BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive, duke@435: VoidClosure* complete_gc); duke@435: duke@435: // Enqueue references with a certain reachability level coleenp@548: void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr); duke@435: duke@435: // "Preclean" all the discovered reference lists duke@435: // by removing references with strongly reachable referents. duke@435: // The first argument is a predicate on an oop that indicates duke@435: // its (strong) reachability and the second is a closure that duke@435: // may be used to incrementalize or abort the precleaning process. duke@435: // The caller is responsible for taking care of potential duke@435: // interference with concurrent operations on these lists duke@435: // (or predicates involved) by other threads. Currently coleenp@4037: // only used by the CMS collector. duke@435: void preclean_discovered_references(BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive, duke@435: VoidClosure* complete_gc, coleenp@4037: YieldClosure* yield); duke@435: duke@435: // Delete entries in the discovered lists that have duke@435: // either a null referent or are not active. Such duke@435: // Reference objects can result from the clearing duke@435: // or enqueueing of Reference objects concurrent duke@435: // with their discovery by a (concurrent) collector. duke@435: // For a definition of "active" see java.lang.ref.Reference; duke@435: // Refs are born active, become inactive when enqueued, duke@435: // and never become active again. The state of being duke@435: // active is encoded as follows: A Ref is active duke@435: // if and only if its "next" field is NULL. duke@435: void clean_up_discovered_references(); duke@435: void clean_up_discovered_reflist(DiscoveredList& refs_list); duke@435: duke@435: // Returns the name of the discovered reference list duke@435: // occupying the i / _num_q slot. jmasa@3357: const char* list_name(uint i); duke@435: coleenp@548: void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor); coleenp@548: duke@435: protected: johnc@3175: // Set the 'discovered' field of the given reference to johnc@3175: // the given value - emitting barriers depending upon johnc@3175: // the value of _discovered_list_needs_barrier. johnc@3175: void set_discovered(oop ref, oop value); johnc@3175: duke@435: // "Preclean" the given discovered reference list duke@435: // by removing references with strongly reachable referents. duke@435: // Currently used in support of CMS only. duke@435: void preclean_discovered_reflist(DiscoveredList& refs_list, duke@435: BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive, duke@435: VoidClosure* complete_gc, duke@435: YieldClosure* yield); duke@435: ysr@2651: // round-robin mod _num_q (not: _not_ mode _max_num_q) jmasa@3357: uint next_id() { jmasa@3357: uint id = _next_id; duke@435: if (++_next_id == _num_q) { duke@435: _next_id = 0; duke@435: } duke@435: return id; duke@435: } duke@435: DiscoveredList* get_discovered_list(ReferenceType rt); duke@435: inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj, coleenp@548: HeapWord* discovered_addr); duke@435: void verify_ok_to_handle_reflists() PRODUCT_RETURN; duke@435: stefank@3115: void clear_discovered_references(DiscoveredList& refs_list); duke@435: void abandon_partial_discovered_list(DiscoveredList& refs_list); duke@435: duke@435: // Calculate the number of jni handles. duke@435: unsigned int count_jni_refs(); duke@435: duke@435: // Balances reference queues. duke@435: void balance_queues(DiscoveredList ref_lists[]); duke@435: duke@435: // Update (advance) the soft ref master clock field. duke@435: void update_soft_ref_master_clock(); duke@435: duke@435: public: duke@435: // constructor duke@435: ReferenceProcessor(): duke@435: _span((HeapWord*)NULL, (HeapWord*)NULL), johnc@3210: _discovered_refs(NULL), duke@435: _discoveredSoftRefs(NULL), _discoveredWeakRefs(NULL), duke@435: _discoveredFinalRefs(NULL), _discoveredPhantomRefs(NULL), duke@435: _discovering_refs(false), duke@435: _discovery_is_atomic(true), duke@435: _enqueuing_is_done(false), duke@435: _discovery_is_mt(false), ysr@777: _discovered_list_needs_barrier(false), ysr@777: _bs(NULL), duke@435: _is_alive_non_header(NULL), duke@435: _num_q(0), jmasa@2188: _max_num_q(0), duke@435: _processing_is_mt(false), duke@435: _next_id(0) ysr@2651: { } duke@435: ysr@2651: // Default parameters give you a vanilla reference processor. ysr@2651: ReferenceProcessor(MemRegion span, jmasa@3357: bool mt_processing = false, uint mt_processing_degree = 1, jmasa@3357: bool mt_discovery = false, uint mt_discovery_degree = 1, ysr@2651: bool atomic_discovery = true, ysr@2651: BoolObjectClosure* is_alive_non_header = NULL, ysr@777: bool discovered_list_needs_barrier = false); duke@435: duke@435: // RefDiscoveryPolicy values johnc@1679: enum DiscoveryPolicy { duke@435: ReferenceBasedDiscovery = 0, johnc@1679: ReferentBasedDiscovery = 1, johnc@1679: DiscoveryPolicyMin = ReferenceBasedDiscovery, johnc@1679: DiscoveryPolicyMax = ReferentBasedDiscovery duke@435: }; duke@435: duke@435: static void init_statics(); duke@435: duke@435: public: duke@435: // get and set "is_alive_non_header" field duke@435: BoolObjectClosure* is_alive_non_header() { duke@435: return _is_alive_non_header; duke@435: } duke@435: void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) { duke@435: _is_alive_non_header = is_alive_non_header; duke@435: } duke@435: duke@435: // get and set span duke@435: MemRegion span() { return _span; } duke@435: void set_span(MemRegion span) { _span = span; } duke@435: duke@435: // start and stop weak ref discovery johnc@3188: void enable_discovery(bool verify_disabled, bool check_no_refs); duke@435: void disable_discovery() { _discovering_refs = false; } duke@435: bool discovery_enabled() { return _discovering_refs; } duke@435: duke@435: // whether discovery is atomic wrt other collectors duke@435: bool discovery_is_atomic() const { return _discovery_is_atomic; } duke@435: void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; } duke@435: ysr@3117: // whether the JDK in which we are embedded is a pre-4965777 JDK, ysr@3117: // and thus whether or not it uses the discovered field to chain ysr@3117: // the entries in the pending list. ysr@3117: static bool pending_list_uses_discovered_field() { ysr@3117: return _pending_list_uses_discovered_field; ysr@3117: } ysr@3117: duke@435: // whether discovery is done by multiple threads same-old-timeously duke@435: bool discovery_is_mt() const { return _discovery_is_mt; } duke@435: void set_mt_discovery(bool mt) { _discovery_is_mt = mt; } duke@435: duke@435: // Whether we are in a phase when _processing_ is MT. duke@435: bool processing_is_mt() const { return _processing_is_mt; } duke@435: void set_mt_processing(bool mt) { _processing_is_mt = mt; } duke@435: duke@435: // whether all enqueuing of weak references is complete duke@435: bool enqueuing_is_done() { return _enqueuing_is_done; } duke@435: void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; } duke@435: duke@435: // iterate over oops duke@435: void weak_oops_do(OopClosure* f); // weak roots duke@435: jmasa@2188: // Balance each of the discovered lists. jmasa@2188: void balance_all_queues(); coleenp@4037: void verify_list(DiscoveredList& ref_list); jmasa@2188: duke@435: // Discover a Reference object, using appropriate discovery criteria duke@435: bool discover_reference(oop obj, ReferenceType rt); duke@435: duke@435: // Process references found during GC (called by the garbage collector) ysr@888: void process_discovered_references(BoolObjectClosure* is_alive, duke@435: OopClosure* keep_alive, duke@435: VoidClosure* complete_gc, duke@435: AbstractRefProcTaskExecutor* task_executor); duke@435: duke@435: public: duke@435: // Enqueue references at end of GC (called by the garbage collector) duke@435: bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL); duke@435: ysr@777: // If a discovery is in process that is being superceded, abandon it: all ysr@777: // the discovered lists will be empty, and all the objects on them will ysr@777: // have NULL discovered fields. Must be called only at a safepoint. ysr@777: void abandon_partial_discovery(); ysr@777: duke@435: // debugging duke@435: void verify_no_references_recorded() PRODUCT_RETURN; ysr@2337: void verify_referent(oop obj) PRODUCT_RETURN; duke@435: duke@435: // clear the discovered lists (unlinking each entry). duke@435: void clear_discovered_references() PRODUCT_RETURN; duke@435: }; duke@435: duke@435: // A utility class to disable reference discovery in duke@435: // the scope which contains it, for given ReferenceProcessor. duke@435: class NoRefDiscovery: StackObj { duke@435: private: duke@435: ReferenceProcessor* _rp; duke@435: bool _was_discovering_refs; duke@435: public: duke@435: NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) { twisti@2144: _was_discovering_refs = _rp->discovery_enabled(); twisti@2144: if (_was_discovering_refs) { duke@435: _rp->disable_discovery(); duke@435: } duke@435: } duke@435: duke@435: ~NoRefDiscovery() { duke@435: if (_was_discovering_refs) { johnc@3175: _rp->enable_discovery(true /*verify_disabled*/, false /*check_no_refs*/); duke@435: } duke@435: } duke@435: }; duke@435: duke@435: duke@435: // A utility class to temporarily mutate the span of the duke@435: // given ReferenceProcessor in the scope that contains it. duke@435: class ReferenceProcessorSpanMutator: StackObj { duke@435: private: duke@435: ReferenceProcessor* _rp; duke@435: MemRegion _saved_span; duke@435: duke@435: public: duke@435: ReferenceProcessorSpanMutator(ReferenceProcessor* rp, duke@435: MemRegion span): duke@435: _rp(rp) { duke@435: _saved_span = _rp->span(); duke@435: _rp->set_span(span); duke@435: } duke@435: duke@435: ~ReferenceProcessorSpanMutator() { duke@435: _rp->set_span(_saved_span); duke@435: } duke@435: }; duke@435: duke@435: // A utility class to temporarily change the MT'ness of duke@435: // reference discovery for the given ReferenceProcessor duke@435: // in the scope that contains it. ysr@2651: class ReferenceProcessorMTDiscoveryMutator: StackObj { duke@435: private: duke@435: ReferenceProcessor* _rp; duke@435: bool _saved_mt; duke@435: duke@435: public: ysr@2651: ReferenceProcessorMTDiscoveryMutator(ReferenceProcessor* rp, ysr@2651: bool mt): duke@435: _rp(rp) { duke@435: _saved_mt = _rp->discovery_is_mt(); duke@435: _rp->set_mt_discovery(mt); duke@435: } duke@435: ysr@2651: ~ReferenceProcessorMTDiscoveryMutator() { duke@435: _rp->set_mt_discovery(_saved_mt); duke@435: } duke@435: }; duke@435: duke@435: duke@435: // A utility class to temporarily change the disposition duke@435: // of the "is_alive_non_header" closure field of the duke@435: // given ReferenceProcessor in the scope that contains it. duke@435: class ReferenceProcessorIsAliveMutator: StackObj { duke@435: private: duke@435: ReferenceProcessor* _rp; duke@435: BoolObjectClosure* _saved_cl; duke@435: duke@435: public: duke@435: ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp, duke@435: BoolObjectClosure* cl): duke@435: _rp(rp) { duke@435: _saved_cl = _rp->is_alive_non_header(); duke@435: _rp->set_is_alive_non_header(cl); duke@435: } duke@435: duke@435: ~ReferenceProcessorIsAliveMutator() { duke@435: _rp->set_is_alive_non_header(_saved_cl); duke@435: } duke@435: }; duke@435: duke@435: // A utility class to temporarily change the disposition duke@435: // of the "discovery_is_atomic" field of the duke@435: // given ReferenceProcessor in the scope that contains it. duke@435: class ReferenceProcessorAtomicMutator: StackObj { duke@435: private: duke@435: ReferenceProcessor* _rp; duke@435: bool _saved_atomic_discovery; duke@435: duke@435: public: duke@435: ReferenceProcessorAtomicMutator(ReferenceProcessor* rp, duke@435: bool atomic): duke@435: _rp(rp) { duke@435: _saved_atomic_discovery = _rp->discovery_is_atomic(); duke@435: _rp->set_atomic_discovery(atomic); duke@435: } duke@435: duke@435: ~ReferenceProcessorAtomicMutator() { duke@435: _rp->set_atomic_discovery(_saved_atomic_discovery); duke@435: } duke@435: }; duke@435: duke@435: duke@435: // A utility class to temporarily change the MT processing duke@435: // disposition of the given ReferenceProcessor instance duke@435: // in the scope that contains it. duke@435: class ReferenceProcessorMTProcMutator: StackObj { duke@435: private: duke@435: ReferenceProcessor* _rp; duke@435: bool _saved_mt; duke@435: duke@435: public: duke@435: ReferenceProcessorMTProcMutator(ReferenceProcessor* rp, duke@435: bool mt): duke@435: _rp(rp) { duke@435: _saved_mt = _rp->processing_is_mt(); duke@435: _rp->set_mt_processing(mt); duke@435: } duke@435: duke@435: ~ReferenceProcessorMTProcMutator() { duke@435: _rp->set_mt_processing(_saved_mt); duke@435: } duke@435: }; duke@435: duke@435: duke@435: // This class is an interface used to implement task execution for the duke@435: // reference processing. duke@435: class AbstractRefProcTaskExecutor { duke@435: public: duke@435: duke@435: // Abstract tasks to execute. duke@435: class ProcessTask; duke@435: class EnqueueTask; duke@435: duke@435: // Executes a task using worker threads. duke@435: virtual void execute(ProcessTask& task) = 0; duke@435: virtual void execute(EnqueueTask& task) = 0; duke@435: duke@435: // Switch to single threaded mode. duke@435: virtual void set_single_threaded_mode() { }; duke@435: }; duke@435: duke@435: // Abstract reference processing task to execute. duke@435: class AbstractRefProcTaskExecutor::ProcessTask { duke@435: protected: duke@435: ProcessTask(ReferenceProcessor& ref_processor, duke@435: DiscoveredList refs_lists[], duke@435: bool marks_oops_alive) duke@435: : _ref_processor(ref_processor), duke@435: _refs_lists(refs_lists), duke@435: _marks_oops_alive(marks_oops_alive) duke@435: { } duke@435: duke@435: public: duke@435: virtual void work(unsigned int work_id, BoolObjectClosure& is_alive, duke@435: OopClosure& keep_alive, duke@435: VoidClosure& complete_gc) = 0; duke@435: duke@435: // Returns true if a task marks some oops as alive. duke@435: bool marks_oops_alive() const duke@435: { return _marks_oops_alive; } duke@435: duke@435: protected: duke@435: ReferenceProcessor& _ref_processor; duke@435: DiscoveredList* _refs_lists; duke@435: const bool _marks_oops_alive; duke@435: }; duke@435: duke@435: // Abstract reference processing task to execute. duke@435: class AbstractRefProcTaskExecutor::EnqueueTask { duke@435: protected: duke@435: EnqueueTask(ReferenceProcessor& ref_processor, duke@435: DiscoveredList refs_lists[], coleenp@548: HeapWord* pending_list_addr, duke@435: int n_queues) duke@435: : _ref_processor(ref_processor), duke@435: _refs_lists(refs_lists), duke@435: _pending_list_addr(pending_list_addr), duke@435: _n_queues(n_queues) duke@435: { } duke@435: duke@435: public: duke@435: virtual void work(unsigned int work_id) = 0; duke@435: duke@435: protected: duke@435: ReferenceProcessor& _ref_processor; duke@435: DiscoveredList* _refs_lists; coleenp@548: HeapWord* _pending_list_addr; duke@435: int _n_queues; duke@435: }; stefank@2314: stefank@2314: #endif // SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP