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/shenandoahGenerationType.hpp"
32 #include "gc/shenandoah/shenandoahGC.hpp"
33 #include "gc/shenandoah/shenandoahPadding.hpp"
34 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
35
36 class ShenandoahOldGeneration;
37 class ShenandoahGeneration;
38 class ShenandoahGenerationalHeap;
39 class ShenandoahHeap;
40
41 class ShenandoahGenerationalControlThread: public ShenandoahController {
42 friend class VMStructs;
43
44 public:
45 typedef enum {
46 none,
47 concurrent_normal,
48 stw_degenerated,
49 stw_full,
50 bootstrapping_old,
51 servicing_old
52 } GCMode;
53
54 private:
55 Monitor _control_lock;
56 Monitor _regulator_lock;
57
58 ShenandoahSharedFlag _allow_old_preemption;
59 ShenandoahSharedFlag _preemption_requested;
60
61 GCCause::Cause _requested_gc_cause;
62 volatile ShenandoahGenerationType _requested_generation;
63 ShenandoahGC::ShenandoahDegenPoint _degen_point;
64 ShenandoahGeneration* _degen_generation;
65
66 shenandoah_padding(0);
67 volatile GCMode _mode;
68 shenandoah_padding(1);
69
70 public:
71 ShenandoahGenerationalControlThread();
72
73 void run_service() override;
74 void stop_service() override;
75
76 void request_gc(GCCause::Cause cause) override;
77
78 // Return true if the request to start a concurrent GC for the given generation succeeded.
79 bool request_concurrent_gc(ShenandoahGenerationType generation);
80
81 GCMode gc_mode() {
82 return _mode;
83 }
84 private:
85
86 // Returns true if the cycle has been cancelled or degenerated.
87 bool check_cancellation_or_degen(ShenandoahGC::ShenandoahDegenPoint point);
88
89 // Returns true if the old generation marking completed (i.e., final mark executed for old generation).
90 bool resume_concurrent_old_cycle(ShenandoahOldGeneration* generation, GCCause::Cause cause);
91 void service_concurrent_cycle(ShenandoahGeneration* generation, GCCause::Cause cause, bool reset_old_bitmap_specially);
92 void service_stw_full_cycle(GCCause::Cause cause);
93 void service_stw_degenerated_cycle(GCCause::Cause cause, ShenandoahGC::ShenandoahDegenPoint point);
94
95 void notify_gc_waiters();
96
97 // Handle GC request.
98 // Blocks until GC is over.
99 void handle_requested_gc(GCCause::Cause cause);
100
101 bool is_explicit_gc(GCCause::Cause cause) const;
102 bool is_implicit_gc(GCCause::Cause cause) const;
103
104 // Returns true if the old generation marking was interrupted to allow a young cycle.
105 bool preempt_old_marking(ShenandoahGenerationType generation);
106
107 void process_phase_timings(const ShenandoahGenerationalHeap* heap);
108
109 void service_concurrent_normal_cycle(ShenandoahGenerationalHeap* heap,
110 ShenandoahGenerationType generation,
111 GCCause::Cause cause);
112
113 void service_concurrent_old_cycle(ShenandoahGenerationalHeap* heap,
114 GCCause::Cause &cause);
115
116 void set_gc_mode(GCMode new_mode);
117
118 static const char* gc_mode_name(GCMode mode);
119
120 void notify_control_thread();
121
122 void service_concurrent_cycle(ShenandoahHeap* heap,
123 ShenandoahGeneration* generation,
124 GCCause::Cause &cause,
125 bool do_old_gc_bootstrap);
126
127 };
128
129 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHGENERATIONALCONTROLTHREAD_HPP