1 /*
 2  * Copyright (c) 2013, 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 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHCONTROLTHREAD_HPP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHCONTROLTHREAD_HPP
27 
28 #include "gc/shared/gcCause.hpp"
29 #include "gc/shared/concurrentGCThread.hpp"
30 #include "gc/shenandoah/shenandoahGC.hpp"
31 #include "gc/shenandoah/shenandoahGenerationType.hpp"
32 #include "gc/shenandoah/shenandoahHeap.hpp"
33 #include "gc/shenandoah/shenandoahPadding.hpp"
34 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
35 
36 class ShenandoahControlThread: public ShenandoahController {
37   friend class VMStructs;
38 
39 private:
40   typedef enum {
41     none,
42     concurrent_normal,
43     stw_degenerated,
44     stw_full
45   } GCMode;
46 
47   ShenandoahSharedFlag _gc_requested;
48   GCCause::Cause       _requested_gc_cause;
49   ShenandoahGC::ShenandoahDegenPoint _degen_point;
50 
51 public:
52   ShenandoahControlThread();
53 
54   void run_service() override;
55   void stop_service() override;
56 
57   void request_gc(GCCause::Cause cause) override;
58 
59 private:
60 
61   bool check_cancellation_or_degen(ShenandoahGC::ShenandoahDegenPoint point);
62   void service_concurrent_normal_cycle(GCCause::Cause cause);
63   void service_stw_full_cycle(GCCause::Cause cause);
64   void service_stw_degenerated_cycle(GCCause::Cause cause, ShenandoahGC::ShenandoahDegenPoint point);
65 
66   void notify_gc_waiters();
67 
68   // Handle GC request.
69   // Blocks until GC is over.
70   void handle_requested_gc(GCCause::Cause cause);
71 };
72 
73 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHCONTROLTHREAD_HPP