1 /*
  2  * Copyright (c) 2017, 2023, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 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,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #include "precompiled.hpp"
 26 #include "classfile/classLoaderData.hpp"
 27 #include "classfile/classLoaderDataGraph.hpp"
 28 #include "gc/g1/g1CollectedHeap.hpp"
 29 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
 30 #include "gc/g1/g1FullCollector.inline.hpp"
 31 #include "gc/g1/g1FullGCAdjustTask.hpp"
 32 #include "gc/g1/g1FullGCCompactionPoint.hpp"
 33 #include "gc/g1/g1FullGCMarker.hpp"
 34 #include "gc/g1/g1FullGCOopClosures.inline.hpp"
 35 #include "gc/g1/heapRegion.inline.hpp"
 36 #include "gc/shared/gcTraceTime.inline.hpp"
 37 #include "gc/shared/referenceProcessor.hpp"
 38 #include "gc/shared/weakProcessor.inline.hpp"
 39 #include "logging/log.hpp"
 40 #include "memory/iterator.inline.hpp"
 41 #include "runtime/atomic.hpp"
 42 
 43 template <bool ALT_FWD>
 44 class G1AdjustLiveClosure : public StackObj {
 45   G1AdjustClosure<ALT_FWD>* _adjust_closure;
 46 public:
 47   G1AdjustLiveClosure(G1AdjustClosure<ALT_FWD>* cl) :
 48     _adjust_closure(cl) { }
 49 
 50   size_t apply(oop object) {
 51     return object->oop_iterate_size(_adjust_closure);
 52   }
 53 };
 54 
 55 class G1AdjustRegionClosure : public HeapRegionClosure {
 56   G1FullCollector* _collector;
 57   G1CMBitMap* _bitmap;
 58   uint _worker_id;
 59  public:
 60   G1AdjustRegionClosure(G1FullCollector* collector, uint worker_id) :
 61     _collector(collector),
 62     _bitmap(collector->mark_bitmap()),
 63     _worker_id(worker_id) { }
 64 
 65   bool do_heap_region(HeapRegion* r) {
 66     if (UseAltGCForwarding) {
 67       return do_heap_region_impl<true>(r);
 68     } else {
 69       return do_heap_region_impl<false>(r);
 70     }
 71   }
 72 
 73 private:
 74   template <bool ALT_FWD>
 75   bool do_heap_region_impl(HeapRegion* r) {
 76     G1AdjustClosure<ALT_FWD> cl(_collector);
 77     if (r->is_humongous()) {
 78       // Special handling for humongous regions to get somewhat better
 79       // work distribution.
 80       oop obj = cast_to_oop(r->humongous_start_region()->bottom());
 81       obj->oop_iterate(&cl, MemRegion(r->bottom(), r->top()));
 82     } else if (!r->is_free()) {
 83       // Free regions do not contain objects to iterate. So skip them.
 84       G1AdjustLiveClosure<ALT_FWD> adjust(&cl);
 85       r->apply_to_marked_objects(_bitmap, &adjust);
 86     }
 87     return false;
 88   }
 89 };
 90 
 91 G1FullGCAdjustTask::G1FullGCAdjustTask(G1FullCollector* collector) :
 92     G1FullGCTask("G1 Adjust", collector),
 93     _root_processor(G1CollectedHeap::heap(), collector->workers()),
 94     _weak_proc_task(collector->workers()),
 95     _hrclaimer(collector->workers()) {
 96   ClassLoaderDataGraph::verify_claimed_marks_cleared(ClassLoaderData::_claim_stw_fullgc_adjust);
 97 }
 98 
 99 template <bool ALT_FWD>
100 void G1FullGCAdjustTask::work_impl(uint worker_id) {
101   Ticks start = Ticks::now();
102   ResourceMark rm;
103 
104   // Adjust preserved marks first since they are not balanced.
105   G1FullGCCompactionPoint* cp = collector()->compaction_point(worker_id);
106   cp->preserved_stack()->adjust_during_full_gc();
107 
108   G1AdjustClosure<ALT_FWD> adjust(collector());
109   {
110     // Adjust the weak roots.
111     AlwaysTrueClosure always_alive;
112     _weak_proc_task.work(worker_id, &always_alive, &adjust);
113   }
114 
115   CLDToOopClosure adjust_cld(&adjust, ClassLoaderData::_claim_stw_fullgc_adjust);
116   CodeBlobToOopClosure adjust_code(&adjust, CodeBlobToOopClosure::FixRelocations);
117   _root_processor.process_all_roots(&adjust, &adjust_cld, &adjust_code);
118 
119   // Now adjust pointers region by region
120   G1AdjustRegionClosure blk(collector(), worker_id);
121   G1CollectedHeap::heap()->heap_region_par_iterate_from_worker_offset(&blk, &_hrclaimer, worker_id);
122   log_task("Adjust task", worker_id, start);
123 }
124 
125 void G1FullGCAdjustTask::work(uint worker_id) {
126   if (UseAltGCForwarding) {
127     work_impl<true>(worker_id);
128   } else {
129     work_impl<false>(worker_id);
130   }
131 }