1 /*
2 * Copyright (c) 2002, 2015, 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.
22 *
23 */
24
25 #ifndef SHARE_VM_GC_SHARED_GCCAUSE_HPP
26 #define SHARE_VM_GC_SHARED_GCCAUSE_HPP
27
28 #include "memory/allocation.hpp"
29
30 //
31 // This class exposes implementation details of the various
32 // collector(s), and we need to be very careful with it. If
33 // use of this class grows, we should split it into public
34 // and implementation-private "causes".
35 //
36
37 class GCCause : public AllStatic {
38 public:
39 enum Cause {
40 /* public */
41 _java_lang_system_gc,
42 _full_gc_alot,
43 _scavenge_alot,
44 _allocation_profiler,
45 _jvmti_force_gc,
46 _gc_locker,
47 _heap_inspection,
48 _heap_dump,
49 _wb_young_gc,
50 _wb_conc_mark,
51 _update_allocation_context_stats_inc,
52 _update_allocation_context_stats_full,
53
54 /* implementation independent, but reserved for GC use */
55 _no_gc,
56 _no_cause_specified,
57 _allocation_failure,
58
59 /* implementation specific */
60
61 _tenured_generation_full,
62 _metadata_GC_threshold,
63
64 _cms_generation_full,
65 _cms_initial_mark,
66 _cms_final_remark,
67 _cms_concurrent_mark,
68
69 _old_generation_expanded_on_last_scavenge,
70 _old_generation_too_full_to_scavenge,
71 _adaptive_size_policy,
72
73 _g1_inc_collection_pause,
74 _g1_humongous_allocation,
75
76 _shenandoah_init_mark,
77
78 _last_ditch_collection,
79
80 _dcmd_gc_run,
81
82 _last_gc_cause
83 };
84
85 inline static bool is_user_requested_gc(GCCause::Cause cause) {
86 return (cause == GCCause::_java_lang_system_gc ||
87 cause == GCCause::_dcmd_gc_run);
88 }
89
90 inline static bool is_serviceability_requested_gc(GCCause::Cause
91 cause) {
92 return (cause == GCCause::_jvmti_force_gc ||
93 cause == GCCause::_heap_inspection ||
94 cause == GCCause::_heap_dump);
95 }
96
97 // Causes for collection of the tenured gernation
98 inline static bool is_tenured_allocation_failure_gc(GCCause::Cause cause) {
99 assert(cause != GCCause::_old_generation_too_full_to_scavenge &&
100 cause != GCCause::_old_generation_expanded_on_last_scavenge,
101 err_msg("This GCCause may be correct but is not expected yet: %s",
102 to_string(cause)));
103 // _tenured_generation_full or _cms_generation_full for full tenured generations
104 // _adaptive_size_policy for a full collection after a young GC
105 // _allocation_failure is the generic cause a collection which could result
106 // in the collection of the tenured generation if there is not enough space
107 // in the tenured generation to support a young GC.
108 // _last_ditch_collection is a collection done to include SoftReferences.
109 return (cause == GCCause::_tenured_generation_full ||
110 cause == GCCause::_cms_generation_full ||
111 cause == GCCause::_adaptive_size_policy ||
112 cause == GCCause::_allocation_failure ||
113 cause == GCCause::_last_ditch_collection);
114 }
115
116 // Causes for collection of the young generation
117 inline static bool is_allocation_failure_gc(GCCause::Cause cause) {
118 // _allocation_failure is the generic cause a collection for allocation failure
119 // _adaptive_size_policy is for a collecton done before a full GC
120 // _last_ditch_collection is a collection done to include SoftReferences.
121 return (cause == GCCause::_allocation_failure ||
122 cause == GCCause::_adaptive_size_policy ||
123 cause == GCCause::_last_ditch_collection);
124 }
125
126 // Return a string describing the GCCause.
127 static const char* to_string(GCCause::Cause cause);
128 };
129
130 // Helper class for doing logging that includes the GC Cause
131 // as a string.
132 class GCCauseString : StackObj {
133 private:
134 static const int _length = 128;
135 char _buffer[_length];
136 int _position;
137
138 public:
139 GCCauseString(const char* prefix, GCCause::Cause cause) {
140 if (PrintGCCause) {
141 _position = jio_snprintf(_buffer, _length, "%s (%s) ", prefix, GCCause::to_string(cause));
142 } else {
143 _position = jio_snprintf(_buffer, _length, "%s ", prefix);
144 }
145 assert(_position >= 0 && _position <= _length,
146 err_msg("Need to increase the buffer size in GCCauseString? %d", _position));
147 }
148
149 GCCauseString& append(const char* str) {
150 int res = jio_snprintf(_buffer + _position, _length - _position, "%s", str);
151 _position += res;
152 assert(res >= 0 && _position <= _length,
153 err_msg("Need to increase the buffer size in GCCauseString? %d", res));
154 return *this;
155 }
156
157 operator const char*() {
158 return _buffer;
159 }
160 };
161
162 #endif // SHARE_VM_GC_SHARED_GCCAUSE_HPP