Fri, 17 May 2013 11:57:05 +0200
8014277: Remove ObjectClosure as base class for BoolObjectClosure
Reviewed-by: brutisso, tschatzl
1 /*
2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
8 *
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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,
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23 */
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1REMSET_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1REMSET_HPP
28 // A G1RemSet provides ways of iterating over pointers into a selected
29 // collection set.
31 class G1CollectedHeap;
32 class CardTableModRefBarrierSet;
33 class ConcurrentG1Refine;
35 // A G1RemSet in which each heap region has a rem set that records the
36 // external heap references into it. Uses a mod ref bs to track updates,
37 // so that they can be used to update the individual region remsets.
39 class G1RemSet: public CHeapObj<mtGC> {
40 protected:
41 G1CollectedHeap* _g1;
42 unsigned _conc_refine_cards;
43 uint n_workers();
45 protected:
46 enum SomePrivateConstants {
47 UpdateRStoMergeSync = 0,
48 MergeRStoDoDirtySync = 1,
49 DoDirtySync = 2,
50 LastSync = 3,
52 SeqTask = 0,
53 NumSeqTasks = 1
54 };
56 CardTableModRefBS* _ct_bs;
57 SubTasksDone* _seq_task;
58 G1CollectorPolicy* _g1p;
60 ConcurrentG1Refine* _cg1r;
62 size_t* _cards_scanned;
63 size_t _total_cards_scanned;
65 // Used for caching the closure that is responsible for scanning
66 // references into the collection set.
67 OopsInHeapRegionClosure** _cset_rs_update_cl;
69 public:
70 // This is called to reset dual hash tables after the gc pause
71 // is finished and the initial hash table is no longer being
72 // scanned.
73 void cleanupHRRS();
75 G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs);
76 ~G1RemSet();
78 // Invoke "blk->do_oop" on all pointers into the CS in objects in regions
79 // outside the CS (having invoked "blk->set_region" to set the "from"
80 // region correctly beforehand.) The "worker_i" param is for the
81 // parallel case where the number of the worker thread calling this
82 // function can be helpful in partitioning the work to be done. It
83 // should be the same as the "i" passed to the calling thread's
84 // work(i) function. In the sequential case this param will be ingored.
85 void oops_into_collection_set_do(OopsInHeapRegionClosure* blk, int worker_i);
87 // Prepare for and cleanup after an oops_into_collection_set_do
88 // call. Must call each of these once before and after (in sequential
89 // code) any threads call oops_into_collection_set_do. (This offers an
90 // opportunity to sequential setup and teardown of structures needed by a
91 // parallel iteration over the CS's RS.)
92 void prepare_for_oops_into_collection_set_do();
93 void cleanup_after_oops_into_collection_set_do();
95 void scanRS(OopsInHeapRegionClosure* oc, int worker_i);
96 void updateRS(DirtyCardQueue* into_cset_dcq, int worker_i);
98 CardTableModRefBS* ct_bs() { return _ct_bs; }
99 size_t cardsScanned() { return _total_cards_scanned; }
101 // Record, if necessary, the fact that *p (where "p" is in region "from",
102 // which is required to be non-NULL) has changed to a new non-NULL value.
103 template <class T> void write_ref(HeapRegion* from, T* p);
104 template <class T> void par_write_ref(HeapRegion* from, T* p, int tid);
106 // Requires "region_bm" and "card_bm" to be bitmaps with 1 bit per region
107 // or card, respectively, such that a region or card with a corresponding
108 // 0 bit contains no part of any live object. Eliminates any remembered
109 // set entries that correspond to dead heap ranges.
110 void scrub(BitMap* region_bm, BitMap* card_bm);
112 // Like the above, but assumes is called in parallel: "worker_num" is the
113 // parallel thread id of the current thread, and "claim_val" is the
114 // value that should be used to claim heap regions.
115 void scrub_par(BitMap* region_bm, BitMap* card_bm,
116 uint worker_num, int claim_val);
118 // Refine the card corresponding to "card_ptr".
119 // If check_for_refs_into_cset is true, a true result is returned
120 // if the given card contains oops that have references into the
121 // current collection set.
122 virtual bool refine_card(jbyte* card_ptr,
123 int worker_i,
124 bool check_for_refs_into_cset);
126 // Print any relevant summary info.
127 virtual void print_summary_info();
129 // Prepare remembered set for verification.
130 virtual void prepare_for_verify();
131 };
133 class CountNonCleanMemRegionClosure: public MemRegionClosure {
134 G1CollectedHeap* _g1;
135 int _n;
136 HeapWord* _start_first;
137 public:
138 CountNonCleanMemRegionClosure(G1CollectedHeap* g1) :
139 _g1(g1), _n(0), _start_first(NULL)
140 {}
141 void do_MemRegion(MemRegion mr);
142 int n() { return _n; };
143 HeapWord* start_first() { return _start_first; }
144 };
146 class UpdateRSOopClosure: public ExtendedOopClosure {
147 HeapRegion* _from;
148 G1RemSet* _rs;
149 int _worker_i;
151 template <class T> void do_oop_work(T* p);
153 public:
154 UpdateRSOopClosure(G1RemSet* rs, int worker_i = 0) :
155 _from(NULL), _rs(rs), _worker_i(worker_i)
156 {}
158 void set_from(HeapRegion* from) {
159 assert(from != NULL, "from region must be non-NULL");
160 _from = from;
161 }
163 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
164 virtual void do_oop(oop* p) { do_oop_work(p); }
166 // Override: this closure is idempotent.
167 // bool idempotent() { return true; }
168 bool apply_to_weak_ref_discovered_field() { return true; }
169 };
171 class UpdateRSetImmediate: public OopsInHeapRegionClosure {
172 private:
173 G1RemSet* _g1_rem_set;
175 template <class T> void do_oop_work(T* p);
176 public:
177 UpdateRSetImmediate(G1RemSet* rs) :
178 _g1_rem_set(rs) {}
180 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
181 virtual void do_oop( oop* p) { do_oop_work(p); }
182 };
185 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1REMSET_HPP