1 /*
2 * Copyright (c) 2021, Red Hat, Inc. 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
27 #include "compiler/oopMap.hpp"
28 #include "gc/shared/workerThread.hpp"
29 #include "gc/shenandoah/shenandoahClosures.inline.hpp"
30 #include "gc/shenandoah/shenandoahGC.hpp"
31 #include "gc/shenandoah/shenandoahHeap.hpp"
32 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
33 #include "gc/shenandoah/shenandoahRootProcessor.inline.hpp"
34 #include "gc/shenandoah/shenandoahUtils.hpp"
35
36 const char* ShenandoahGC::degen_point_to_string(ShenandoahDegenPoint point) {
37 switch(point) {
38 case _degenerated_unset:
39 return "<UNSET>";
40 case _degenerated_outside_cycle:
41 return "Outside of Cycle";
42 case _degenerated_mark:
43 return "Mark";
44 case _degenerated_evac:
45 return "Evacuation";
46 case _degenerated_updaterefs:
47 return "Update References";
48 default:
49 ShouldNotReachHere();
50 return "ERROR";
51 }
52 }
53
54 class ShenandoahUpdateRootsTask : public WorkerTask {
55 private:
56 ShenandoahRootUpdater* _root_updater;
57 bool _check_alive;
58 public:
59 ShenandoahUpdateRootsTask(ShenandoahRootUpdater* root_updater, bool check_alive) :
60 WorkerTask("Shenandoah Update Roots"),
61 _root_updater(root_updater),
62 _check_alive(check_alive){
63 }
64
65 void work(uint worker_id) {
66 assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Must be at a safepoint");
67 ShenandoahParallelWorkerSession worker_session(worker_id);
68
69 ShenandoahUpdateRefsClosure cl;
70 if (_check_alive) {
71 ShenandoahForwardedIsAliveClosure is_alive;
72 _root_updater->roots_do<ShenandoahForwardedIsAliveClosure, ShenandoahUpdateRefsClosure>(worker_id, &is_alive, &cl);
73 } else {
74 AlwaysTrueClosure always_true;;
75 _root_updater->roots_do<AlwaysTrueClosure, ShenandoahUpdateRefsClosure>(worker_id, &always_true, &cl);
76 }
77 }
78 };
79
80 void ShenandoahGC::update_roots(bool full_gc) {
81 assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Must be at a safepoint");
82 assert(ShenandoahHeap::heap()->is_full_gc_in_progress() ||
83 ShenandoahHeap::heap()->is_degenerated_gc_in_progress(),
84 "Only for degenerated GC and full GC");
85
86 bool check_alive = !full_gc;
87 ShenandoahPhaseTimings::Phase p = full_gc ?
88 ShenandoahPhaseTimings::full_gc_update_roots :
89 ShenandoahPhaseTimings::degen_gc_update_roots;
90
91 ShenandoahGCPhase phase(p);
92 #if COMPILER2_OR_JVMCI
93 DerivedPointerTable::clear();
94 #endif
95
96 ShenandoahHeap* const heap = ShenandoahHeap::heap();
97 WorkerThreads* workers = heap->workers();
98 uint nworkers = workers->active_workers();
99
100 ShenandoahRootUpdater root_updater(nworkers, p);
101 ShenandoahUpdateRootsTask update_roots(&root_updater, check_alive);
102 workers->run_task(&update_roots);
103
104 #if COMPILER2_OR_JVMCI
105 DerivedPointerTable::update_pointers();
106 #endif
107 }