1 /*
2 * Copyright (c) 2013, 2021, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHGENERATIONALCONTROLTHREAD_HPP
27 #define SHARE_GC_SHENANDOAH_SHENANDOAHGENERATIONALCONTROLTHREAD_HPP
28
29 #include "gc/shared/gcCause.hpp"
30 #include "gc/shenandoah/shenandoahController.hpp"
31 #include "gc/shenandoah/shenandoahGC.hpp"
32 #include "gc/shenandoah/shenandoahHeap.hpp"
33 #include "gc/shenandoah/shenandoahPadding.hpp"
34 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
35
36 class ShenandoahOldGeneration;
37
38 class ShenandoahGenerationalControlThread: public ShenandoahController {
39 friend class VMStructs;
40
41 public:
42 typedef enum {
43 none,
44 concurrent_normal,
45 stw_degenerated,
46 stw_full,
47 bootstrapping_old,
48 servicing_old
49 } GCMode;
50
51 private:
52 Monitor _control_lock;
53 Monitor _regulator_lock;
54
55 ShenandoahSharedFlag _allow_old_preemption;
56 ShenandoahSharedFlag _preemption_requested;
57
58 GCCause::Cause _requested_gc_cause;
59 volatile ShenandoahGenerationType _requested_generation;
60 ShenandoahGC::ShenandoahDegenPoint _degen_point;
61 ShenandoahGeneration* _degen_generation;
62
63 shenandoah_padding(0);
64 volatile GCMode _mode;
65 shenandoah_padding(1);
66
67 public:
68 ShenandoahGenerationalControlThread();
69
70 void run_service() override;
71 void stop_service() override;
72
73 void request_gc(GCCause::Cause cause) override;
74
75 // Return true if the request to start a concurrent GC for the given generation succeeded.
76 bool request_concurrent_gc(ShenandoahGenerationType generation);
77
78 GCMode gc_mode() {
79 return _mode;
80 }
81 private:
82
83 // Returns true if the cycle has been cancelled or degenerated.
84 bool check_cancellation_or_degen(ShenandoahGC::ShenandoahDegenPoint point);
85
86 // Returns true if the old generation marking completed (i.e., final mark executed for old generation).
87 bool resume_concurrent_old_cycle(ShenandoahOldGeneration* generation, GCCause::Cause cause);
88 void service_concurrent_cycle(ShenandoahGeneration* generation, GCCause::Cause cause, bool reset_old_bitmap_specially);
89 void service_stw_full_cycle(GCCause::Cause cause);
90 void service_stw_degenerated_cycle(GCCause::Cause cause, ShenandoahGC::ShenandoahDegenPoint point);
91
92 void notify_gc_waiters();
93
94 // Handle GC request.
95 // Blocks until GC is over.
96 void handle_requested_gc(GCCause::Cause cause);
97
98 bool is_explicit_gc(GCCause::Cause cause) const;
99 bool is_implicit_gc(GCCause::Cause cause) const;
100
101 // Returns true if the old generation marking was interrupted to allow a young cycle.
102 bool preempt_old_marking(ShenandoahGenerationType generation);
103
104 void process_phase_timings(const ShenandoahHeap* heap);
105
106 void service_concurrent_normal_cycle(ShenandoahHeap* heap,
107 ShenandoahGenerationType generation,
108 GCCause::Cause cause);
109
110 void service_concurrent_old_cycle(ShenandoahHeap* heap,
111 GCCause::Cause &cause);
112
113 void set_gc_mode(GCMode new_mode);
114
115 static const char* gc_mode_name(GCMode mode);
116
117 void notify_control_thread();
118
119 void service_concurrent_cycle(ShenandoahHeap* heap,
120 ShenandoahGeneration* generation,
121 GCCause::Cause &cause,
122 bool do_old_gc_bootstrap);
123
124 };
125
126 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHGENERATIONALCONTROLTHREAD_HPP