--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1RemSet.hpp Wed May 13 15:16:06 2015 +0200
@@ -0,0 +1,178 @@
+/*
+ * Copyright (c) 2001, 2015, 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/g1RemSetSummary.hpp"
+
+// A G1RemSet provides ways of iterating over pointers into a selected
+// collection set.
+
+class G1CollectedHeap;
+class ConcurrentG1Refine;
+class G1ParPushHeapRSClosure;
+
+// 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:
+ G1RemSetSummary _prev_period_summary;
+protected:
+ G1CollectedHeap* _g1;
+ size_t _conc_refine_cards;
+ uint n_workers();
+
+protected:
+ enum SomePrivateConstants {
+ UpdateRStoMergeSync = 0,
+ MergeRStoDoDirtySync = 1,
+ DoDirtySync = 2,
+ LastSync = 3,
+
+ SeqTask = 0,
+ NumSeqTasks = 1
+ };
+
+ CardTableModRefBS* _ct_bs;
+ G1CollectorPolicy* _g1p;
+
+ ConcurrentG1Refine* _cg1r;
+
+ size_t* _cards_scanned;
+ size_t _total_cards_scanned;
+
+ // Used for caching the closure that is responsible for scanning
+ // references into the collection set.
+ G1ParPushHeapRSClosure** _cset_rs_update_cl;
+
+ // Print the given summary info
+ virtual void print_summary_info(G1RemSetSummary * summary, const char * header = NULL);
+public:
+ // 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);
+ ~G1RemSet();
+
+ // Invoke "blk->do_oop" on all pointers into the collection set
+ // from objects in regions outside the collection set (having
+ // invoked "blk->set_region" to set the "from" region correctly
+ // beforehand.)
+ //
+ // Invoke code_root_cl->do_code_blob on the unmarked nmethods
+ // on the strong code roots list for each region in the
+ // collection set.
+ //
+ // The "worker_i" param is for the parallel case where the id
+ // of the worker thread calling this function can be helpful in
+ // partitioning the work to be done. It should be the same as
+ // the "i" passed to the calling thread's work(i) function.
+ // In the sequential case this param will be ignored.
+ void oops_into_collection_set_do(G1ParPushHeapRSClosure* blk,
+ CodeBlobClosure* code_root_cl,
+ 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 threads call oops_into_collection_set_do. (This offers an
+ // opportunity to sequential setup and teardown of structures needed by a
+ // parallel iteration over the CS's RS.)
+ void prepare_for_oops_into_collection_set_do();
+ void cleanup_after_oops_into_collection_set_do();
+
+ void scanRS(G1ParPushHeapRSClosure* oc,
+ CodeBlobClosure* code_root_cl,
+ uint worker_i);
+
+ void updateRS(DirtyCardQueue* into_cset_dcq, uint worker_i);
+
+ CardTableModRefBS* ct_bs() { return _ct_bs; }
+ size_t cardsScanned() { return _total_cards_scanned; }
+
+ // 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 write_ref(HeapRegion* from, T* p);
+ template <class T> void par_write_ref(HeapRegion* from, T* p, uint tid);
+
+ // Requires "region_bm" and "card_bm" to be bitmaps with 1 bit per region
+ // or card, respectively, such that a region or card with a corresponding
+ // 0 bit contains no part of any live object. Eliminates any remembered
+ // set entries that correspond to dead heap ranges. "worker_num" is the
+ // parallel thread id of the current thread, and "hrclaimer" is the
+ // HeapRegionClaimer that should be used.
+ void scrub(BitMap* region_bm, BitMap* card_bm, uint worker_num, HeapRegionClaimer* hrclaimer);
+
+ // Refine the card corresponding to "card_ptr".
+ // If check_for_refs_into_cset is true, a true result is returned
+ // if the given card contains oops that have references into the
+ // current collection set.
+ virtual bool refine_card(jbyte* card_ptr,
+ uint worker_i,
+ bool check_for_refs_into_cset);
+
+ // Print accumulated summary info from the start of the VM.
+ virtual void print_summary_info();
+
+ // Print accumulated summary info from the last time called.
+ virtual void print_periodic_summary_info(const char* header);
+
+ // Prepare remembered set for verification.
+ virtual void prepare_for_verify();
+
+ size_t conc_refine_cards() const {
+ return _conc_refine_cards;
+ }
+};
+
+class UpdateRSOopClosure: public ExtendedOopClosure {
+ HeapRegion* _from;
+ G1RemSet* _rs;
+ uint _worker_i;
+
+ template <class T> void do_oop_work(T* p);
+
+public:
+ UpdateRSOopClosure(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); }
+
+ // Override: this closure is idempotent.
+ // bool idempotent() { return true; }
+ bool apply_to_weak_ref_discovered_field() { return true; }
+};
+
+#endif // SHARE_VM_GC_G1_G1REMSET_HPP