1 /*
 2  * Copyright (c) 2021, Red Hat, Inc. All rights reserved.
 3  * Copyright (c) 2020, 2024, Oracle and/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
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25 
26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHSTACKWATERMARK_HPP
27 #define SHARE_GC_SHENANDOAH_SHENANDOAHSTACKWATERMARK_HPP
28 
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/barrierSetNMethod.hpp"
31 #include "gc/shenandoah/shenandoahClosures.hpp"
32 #include "memory/allocation.hpp"
33 #include "memory/iterator.hpp"
34 #include "oops/oopsHierarchy.hpp"
35 #include "runtime/stackWatermark.hpp"
36 #include "utilities/globalDefinitions.hpp"
37 
38 class frame;
39 class JavaThread;
40 
41 class ShenandoahOnStackNMethodClosure : public NMethodClosure {
42 private:
43   BarrierSetNMethod* _bs_nm;
44 
45   void do_nmethod(nmethod* nm);
46 public:
47   ShenandoahOnStackNMethodClosure();
48 };
49 
50 class ShenandoahStackWatermark : public StackWatermark {
51 private:
52   // Start epochs from 1 to catch uninitialized paths.
53   // Wrap the epoch around smaller range to avoid truncation
54   // in StackWatermark encoding and verify the wraparound in tests.
55   static constexpr uint32_t MIN_EPOCH_ID = 1;
56   static constexpr uint32_t MAX_EPOCH_ID = (1 << 10);
57 
58   static uint32_t                      _epoch_id;
59   ShenandoahHeap* const                _heap;
60   ThreadLocalAllocStats                _stats;
61 
62   // Closures
63   ShenandoahNoOpClosure                _no_op_cl;
64   ShenandoahKeepAliveClosure           _keep_alive_cl;
65   ShenandoahEvacuateUpdateRootsClosure _evac_update_oop_cl;
66   ShenandoahOnStackNMethodClosure      _nm_cl;
67 public:
68   ShenandoahStackWatermark(JavaThread* jt);
69   ThreadLocalAllocStats& stats();
70 
71   static void change_epoch_id();
72 private:
73   OopClosure* closure_from_context(void* context);
74   uint32_t epoch_id() const;
75   void start_processing_impl(void* context);
76   void process(const frame& fr, RegisterMap& register_map, void* context);
77 
78   void retire_tlab();
79 };
80 
81 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHSTACKWATERMARK_HPP