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 _last_ditch_collection, 77 78 _dcmd_gc_run, 79 80 _last_gc_cause 81 }; 82 83 inline static bool is_user_requested_gc(GCCause::Cause cause) { 84 return (cause == GCCause::_java_lang_system_gc || 85 cause == GCCause::_dcmd_gc_run); 86 } 87 88 inline static bool is_serviceability_requested_gc(GCCause::Cause 89 cause) { 90 return (cause == GCCause::_jvmti_force_gc || 91 cause == GCCause::_heap_inspection || 92 cause == GCCause::_heap_dump); 93 } 94 95 // Causes for collection of the tenured gernation 96 inline static bool is_tenured_allocation_failure_gc(GCCause::Cause cause) { 97 assert(cause != GCCause::_old_generation_too_full_to_scavenge && 98 cause != GCCause::_old_generation_expanded_on_last_scavenge, 99 "This GCCause may be correct but is not expected yet: %s", 100 to_string(cause)); 101 // _tenured_generation_full or _cms_generation_full for full tenured generations 102 // _adaptive_size_policy for a full collection after a young GC 103 // _allocation_failure is the generic cause a collection which could result 104 // in the collection of the tenured generation if there is not enough space 105 // in the tenured generation to support a young GC. 106 // _last_ditch_collection is a collection done to include SoftReferences. 107 return (cause == GCCause::_tenured_generation_full || 108 cause == GCCause::_cms_generation_full || 109 cause == GCCause::_adaptive_size_policy || 110 cause == GCCause::_allocation_failure || 111 cause == GCCause::_last_ditch_collection); 112 } 113 114 // Causes for collection of the young generation 115 inline static bool is_allocation_failure_gc(GCCause::Cause cause) { 116 // _allocation_failure is the generic cause a collection for allocation failure 117 // _adaptive_size_policy is for a collecton done before a full GC 118 // _last_ditch_collection is a collection done to include SoftReferences. 119 return (cause == GCCause::_allocation_failure || 120 cause == GCCause::_adaptive_size_policy || 121 cause == GCCause::_last_ditch_collection); 122 } 123 124 // Return a string describing the GCCause. 125 static const char* to_string(GCCause::Cause cause); 126 }; 127 128 // Helper class for doing logging that includes the GC Cause 129 // as a string. 130 class GCCauseString : StackObj { 131 private: 132 static const int _length = 128; 133 char _buffer[_length]; 134 int _position; 135 136 public: 137 GCCauseString(const char* prefix, GCCause::Cause cause) { 138 if (PrintGCCause) { 139 _position = jio_snprintf(_buffer, _length, "%s (%s) ", prefix, GCCause::to_string(cause)); 140 } else { 141 _position = jio_snprintf(_buffer, _length, "%s ", prefix); 142 } 143 assert(_position >= 0 && _position <= _length, 144 "Need to increase the buffer size in GCCauseString? %d", _position); 145 } 146 147 GCCauseString& append(const char* str) { 148 int res = jio_snprintf(_buffer + _position, _length - _position, "%s", str); 149 _position += res; 150 assert(res >= 0 && _position <= _length, 151 "Need to increase the buffer size in GCCauseString? %d", res); 152 return *this; 153 } 154 155 operator const char*() { 156 return _buffer; 157 } 158 }; 159 160 #endif // SHARE_VM_GC_SHARED_GCCAUSE_HPP