--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1RemSet.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,215 @@
+/*
+ * Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_G1_G1REMSET_HPP
+#define SHARE_VM_GC_G1_G1REMSET_HPP
+
+#include "gc/g1/dirtyCardQueue.hpp"
+#include "gc/g1/g1CardLiveData.hpp"
+#include "gc/g1/g1RemSetSummary.hpp"
+#include "gc/g1/heapRegion.hpp"
+#include "memory/allocation.hpp"
+#include "memory/iterator.hpp"
+
+// A G1RemSet provides ways of iterating over pointers into a selected
+// collection set.
+
+class BitMap;
+class CardTableModRefBS;
+class G1BlockOffsetTable;
+class CodeBlobClosure;
+class G1CollectedHeap;
+class G1HotCardCache;
+class G1RemSetScanState;
+class G1ParScanThreadState;
+class G1Policy;
+class G1SATBCardTableModRefBS;
+class G1ScanObjsDuringScanRSClosure;
+class G1ScanObjsDuringUpdateRSClosure;
+class HeapRegionClaimer;
+
+// A G1RemSet in which each heap region has a rem set that records the
+// external heap references into it. Uses a mod ref bs to track updates,
+// so that they can be used to update the individual region remsets.
+class G1RemSet: public CHeapObj<mtGC> {
+private:
+ G1RemSetScanState* _scan_state;
+ G1CardLiveData _card_live_data;
+
+ G1RemSetSummary _prev_period_summary;
+
+ // Scan all remembered sets of the collection set for references into the collection
+ // set.
+ void scan_rem_set(G1ParScanThreadState* pss,
+ CodeBlobClosure* heap_region_codeblobs,
+ uint worker_i);
+
+ // Flush remaining refinement buffers for cross-region references to either evacuate references
+ // into the collection set or update the remembered set.
+ void update_rem_set(G1ParScanThreadState* pss, uint worker_i);
+
+ G1CollectedHeap* _g1;
+ size_t _num_conc_refined_cards; // Number of cards refined concurrently to the mutator.
+
+ CardTableModRefBS* _ct_bs;
+ G1Policy* _g1p;
+ G1HotCardCache* _hot_card_cache;
+
+public:
+ // Gives an approximation on how many threads can be expected to add records to
+ // a remembered set in parallel. This can be used for sizing data structures to
+ // decrease performance losses due to data structure sharing.
+ // Examples for quantities that influence this value are the maximum number of
+ // mutator threads, maximum number of concurrent refinement or GC threads.
+ static uint num_par_rem_sets();
+
+ // Initialize data that depends on the heap size being known.
+ void initialize(size_t capacity, uint max_regions);
+
+ // This is called to reset dual hash tables after the gc pause
+ // is finished and the initial hash table is no longer being
+ // scanned.
+ void cleanupHRRS();
+
+ G1RemSet(G1CollectedHeap* g1,
+ CardTableModRefBS* ct_bs,
+ G1HotCardCache* hot_card_cache);
+ ~G1RemSet();
+
+ // Process all oops in the collection set from the cards in the refinement buffers and
+ // remembered sets using pss.
+ //
+ // Further applies heap_region_codeblobs on the oops of the unmarked nmethods on the strong code
+ // roots list for each region in the collection set.
+ void oops_into_collection_set_do(G1ParScanThreadState* pss,
+ CodeBlobClosure* heap_region_codeblobs,
+ uint worker_i);
+
+ // Prepare for and cleanup after an oops_into_collection_set_do
+ // call. Must call each of these once before and after (in sequential
+ // code) any thread calls oops_into_collection_set_do.
+ void prepare_for_oops_into_collection_set_do();
+ void cleanup_after_oops_into_collection_set_do();
+
+ G1RemSetScanState* scan_state() const { return _scan_state; }
+
+ // Record, if necessary, the fact that *p (where "p" is in region "from",
+ // which is required to be non-NULL) has changed to a new non-NULL value.
+ template <class T> void par_write_ref(HeapRegion* from, T* p, uint tid);
+
+ // Eliminates any remembered set entries that correspond to dead heap ranges.
+ void scrub(uint worker_num, HeapRegionClaimer* hrclaimer);
+
+ // Refine the card corresponding to "card_ptr". Safe to be called concurrently
+ // to the mutator.
+ void refine_card_concurrently(jbyte* card_ptr,
+ uint worker_i);
+
+ // Refine the card corresponding to "card_ptr", applying the given closure to
+ // all references found. Must only be called during gc.
+ // Returns whether the card has been scanned.
+ bool refine_card_during_gc(jbyte* card_ptr, G1ScanObjsDuringUpdateRSClosure* update_rs_cl);
+
+ // Print accumulated summary info from the start of the VM.
+ void print_summary_info();
+
+ // Print accumulated summary info from the last time called.
+ void print_periodic_summary_info(const char* header, uint period_count);
+
+ size_t num_conc_refined_cards() const { return _num_conc_refined_cards; }
+
+ void create_card_live_data(WorkGang* workers, G1CMBitMap* mark_bitmap);
+ void finalize_card_live_data(WorkGang* workers, G1CMBitMap* mark_bitmap);
+
+ // Verify that the liveness count data created concurrently matches one created
+ // during this safepoint.
+ void verify_card_live_data(WorkGang* workers, G1CMBitMap* actual_bitmap);
+
+ void clear_card_live_data(WorkGang* workers);
+
+#ifdef ASSERT
+ void verify_card_live_data_is_clear();
+#endif
+};
+
+class G1ScanRSForRegionClosure : public HeapRegionClosure {
+ G1RemSetScanState* _scan_state;
+
+ size_t _cards_scanned;
+ size_t _cards_claimed;
+ size_t _cards_skipped;
+
+ G1CollectedHeap* _g1h;
+
+ G1ScanObjsDuringScanRSClosure* _scan_objs_on_card_cl;
+ CodeBlobClosure* _code_root_cl;
+
+ G1BlockOffsetTable* _bot;
+ G1SATBCardTableModRefBS *_ct_bs;
+
+ double _strong_code_root_scan_time_sec;
+ uint _worker_i;
+
+ void claim_card(size_t card_index, const uint region_idx_for_card);
+ void scan_card(MemRegion mr, uint region_idx_for_card);
+ void scan_strong_code_roots(HeapRegion* r);
+public:
+ G1ScanRSForRegionClosure(G1RemSetScanState* scan_state,
+ G1ScanObjsDuringScanRSClosure* scan_obj_on_card,
+ CodeBlobClosure* code_root_cl,
+ uint worker_i);
+
+ bool doHeapRegion(HeapRegion* r);
+
+ double strong_code_root_scan_time_sec() {
+ return _strong_code_root_scan_time_sec;
+ }
+
+ size_t cards_scanned() const { return _cards_scanned; }
+ size_t cards_claimed() const { return _cards_claimed; }
+ size_t cards_skipped() const { return _cards_skipped; }
+};
+
+class RebuildRSOopClosure: public ExtendedOopClosure {
+ HeapRegion* _from;
+ G1RemSet* _rs;
+ uint _worker_i;
+
+ template <class T> void do_oop_work(T* p);
+
+public:
+ RebuildRSOopClosure(G1RemSet* rs, uint worker_i = 0) :
+ _from(NULL), _rs(rs), _worker_i(worker_i)
+ {}
+
+ void set_from(HeapRegion* from) {
+ assert(from != NULL, "from region must be non-NULL");
+ _from = from;
+ }
+
+ virtual void do_oop(narrowOop* p) { do_oop_work(p); }
+ virtual void do_oop(oop* p) { do_oop_work(p); }
+};
+
+#endif // SHARE_VM_GC_G1_G1REMSET_HPP