1 /*
2 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. 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.
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23 */
24
25 #ifndef SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP
26 #define SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP
27
28 #include "gc/shared/strongRootsScope.hpp"
29 #include "memory/allocation.hpp"
30 #include "runtime/mutex.hpp"
31
32 class CLDClosure;
33 class CodeBlobClosure;
34 class G1CollectedHeap;
35 class G1EvacuationRootClosures;
36 class G1GCPhaseTimes;
37 class G1RootClosures;
38 class Monitor;
39 class OopClosure;
40 class SubTasksDone;
41
42 // Scoped object to assist in applying oop, CLD and code blob closures to
43 // root locations. Handles claiming of different root scanning tasks
44 // and takes care of global state for root scanning via a StrongRootsScope.
45 // In the parallel case there is a shared G1RootProcessor object where all
46 // worker thread call the process_roots methods.
47 class G1RootProcessor : public StackObj {
48 G1CollectedHeap* _g1h;
49 SubTasksDone _process_strong_tasks;
50 StrongRootsScope _srs;
51
52 // Used to implement the Thread work barrier.
53 Monitor _lock;
54 volatile jint _n_workers_discovered_strong_classes;
55
56 enum G1H_process_roots_tasks {
57 G1RP_PS_Universe_oops_do,
58 G1RP_PS_JNIHandles_oops_do,
59 G1RP_PS_ObjectSynchronizer_oops_do,
60 G1RP_PS_Management_oops_do,
61 G1RP_PS_SystemDictionary_oops_do,
62 G1RP_PS_ClassLoaderDataGraph_oops_do,
63 G1RP_PS_jvmti_oops_do,
64 G1RP_PS_CodeCache_oops_do,
65 G1RP_PS_aot_oops_do,
66 G1RP_PS_filter_satb_buffers,
67 G1RP_PS_refProcessor_oops_do,
68 G1RP_PS_weakProcessor_oops_do,
69 // Leave this one last.
70 G1RP_PS_NumElements
71 };
72
73 void worker_has_discovered_all_strong_classes();
74 void wait_until_all_strong_classes_discovered();
75
76 void process_all_roots(OopClosure* oops,
77 CLDClosure* clds,
78 CodeBlobClosure* blobs,
79 bool process_string_table);
80
81 void process_java_roots(G1RootClosures* closures,
82 G1GCPhaseTimes* phase_times,
83 uint worker_i);
84
85 void process_vm_roots(G1RootClosures* closures,
86 G1GCPhaseTimes* phase_times,
87 uint worker_i);
88
89 void process_string_table_roots(G1RootClosures* closures,
90 G1GCPhaseTimes* phase_times,
91 uint worker_i);
92
93 void process_code_cache_roots(CodeBlobClosure* code_closure,
94 G1GCPhaseTimes* phase_times,
95 uint worker_i);
96
97 public:
98 G1RootProcessor(G1CollectedHeap* g1h, uint n_workers);
99
100 // Apply closures to the strongly and weakly reachable roots in the system
101 // in a single pass.
102 // Record and report timing measurements for sub phases using the worker_i
103 void evacuate_roots(G1EvacuationRootClosures* closures, uint worker_i);
104
105 // Apply oops, clds and blobs to all strongly reachable roots in the system
106 void process_strong_roots(OopClosure* oops,
107 CLDClosure* clds,
108 CodeBlobClosure* blobs);
109
110 // Apply oops, clds and blobs to strongly and weakly reachable roots in the system
111 void process_all_roots(OopClosure* oops,
112 CLDClosure* clds,
113 CodeBlobClosure* blobs);
114
115 // Apply oops, clds and blobs to strongly and weakly reachable roots in the system,
116 // the only thing different from process_all_roots is that we skip the string table
117 // to avoid keeping every string live when doing class unloading.
118 void process_all_roots_no_string_table(OopClosure* oops,
119 CLDClosure* clds,
120 CodeBlobClosure* blobs);
121
122 // Apply closure to weak roots in the system. Used during the adjust phase
123 // for the Full GC.
124 void process_full_gc_weak_roots(OopClosure* oops);
125
126 // Number of worker threads used by the root processor.
127 uint n_workers() const;
128 };
129
130 #endif // SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP