1 /*
  2  * Copyright (c) 2013, 2021, Red Hat, Inc. All rights reserved.
  3  * Copyright Amazon.com Inc. 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
 21  * or visit www.oracle.com if you need additional information or have any
 22  * questions.
 23  *
 24  */
 25 
 26 #include "precompiled.hpp"
 27 
 28 #include "gc/shenandoah/shenandoahCollectorPolicy.hpp"
 29 #include "gc/shenandoah/shenandoahGC.hpp"
 30 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
 31 #include "runtime/os.hpp"
 32 
 33 ShenandoahCollectorPolicy::ShenandoahCollectorPolicy() :
 34   _success_concurrent_gcs(0),
 35   _abbreviated_concurrent_gcs(0),
 36   _success_degenerated_gcs(0),
 37   _abbreviated_degenerated_gcs(0),
 38   _success_full_gcs(0),
 39   _consecutive_degenerated_gcs(0),
 40   _consecutive_young_gcs(0),
 41   _mixed_gcs(0),
 42   _success_old_gcs(0),
 43   _interrupted_old_gcs(0),
 44   _alloc_failure_degenerated(0),
 45   _alloc_failure_degenerated_upgrade_to_full(0),
 46   _alloc_failure_full(0) {





 47 
 48   Copy::zero_to_bytes(_degen_point_counts, sizeof(size_t) * ShenandoahGC::_DEGENERATED_LIMIT);
 49   Copy::zero_to_bytes(_collection_cause_counts, sizeof(size_t) * GCCause::_last_gc_cause);
 50 
 51   _tracer = new ShenandoahTracer();













 52 }
 53 
 54 void ShenandoahCollectorPolicy::record_collection_cause(GCCause::Cause cause) {
 55   assert(cause < GCCause::_last_gc_cause, "Invalid GCCause");
 56   _collection_cause_counts[cause]++;
 57 }
 58 
 59 void ShenandoahCollectorPolicy::record_alloc_failure_to_full() {
 60   _alloc_failure_full++;
 61 }
 62 
 63 void ShenandoahCollectorPolicy::record_alloc_failure_to_degenerated(ShenandoahGC::ShenandoahDegenPoint point) {
 64   assert(point < ShenandoahGC::_DEGENERATED_LIMIT, "sanity");
 65   _alloc_failure_degenerated++;
 66   _degen_point_counts[point]++;
 67 }
 68 
 69 void ShenandoahCollectorPolicy::record_degenerated_upgrade_to_full() {
 70   _consecutive_degenerated_gcs = 0;
 71   _alloc_failure_degenerated_upgrade_to_full++;
 72 }
 73 
 74 void ShenandoahCollectorPolicy::record_success_concurrent(bool is_young, bool is_abbreviated) {
 75   update_young(is_young);
 76 
 77   _consecutive_degenerated_gcs = 0;
 78   _success_concurrent_gcs++;
 79   if (is_abbreviated) {
 80     _abbreviated_concurrent_gcs++;
 81   }
 82 }
 83 
 84 void ShenandoahCollectorPolicy::record_mixed_cycle() {
 85   _mixed_gcs++;
 86 }
 87 
 88 void ShenandoahCollectorPolicy::record_success_old() {
 89   _consecutive_young_gcs = 0;
 90   _success_old_gcs++;
 91 }
 92 
 93 void ShenandoahCollectorPolicy::record_interrupted_old() {
 94   _consecutive_young_gcs = 0;
 95   _interrupted_old_gcs++;
 96 }
 97 
 98 void ShenandoahCollectorPolicy::record_success_degenerated(bool is_young, bool is_abbreviated) {
 99   update_young(is_young);
100 
101   _success_degenerated_gcs++;
102   _consecutive_degenerated_gcs++;
103   if (is_abbreviated) {
104     _abbreviated_degenerated_gcs++;
105   }
106 }
107 
108 void ShenandoahCollectorPolicy::update_young(bool is_young) {
109   if (is_young) {
110     _consecutive_young_gcs++;
111   } else {
112     _consecutive_young_gcs = 0;
113   }
114 }
115 
116 void ShenandoahCollectorPolicy::record_success_full() {
117   _consecutive_degenerated_gcs = 0;
118   _consecutive_young_gcs = 0;
119   _success_full_gcs++;
120 }
121 
122 void ShenandoahCollectorPolicy::record_shutdown() {
123   _in_shutdown.set();
124 }
125 
126 bool ShenandoahCollectorPolicy::is_at_shutdown() {
127   return _in_shutdown.is_set();
128 }
129 
130 bool is_explicit_gc(GCCause::Cause cause) {
131   return GCCause::is_user_requested_gc(cause)
132       || GCCause::is_serviceability_requested_gc(cause);
133 }
134 
135 bool is_implicit_gc(GCCause::Cause cause) {
136   return cause != GCCause::_no_gc
137       && cause != GCCause::_shenandoah_concurrent_gc
138       && cause != GCCause::_allocation_failure
139       && !is_explicit_gc(cause);
140 }
141 
142 #ifdef ASSERT
143 bool is_valid_request(GCCause::Cause cause) {
144   return is_explicit_gc(cause)
145       || cause == GCCause::_metadata_GC_clear_soft_refs
146       || cause == GCCause::_codecache_GC_aggressive
147       || cause == GCCause::_codecache_GC_threshold
148       || cause == GCCause::_full_gc_alot
149       || cause == GCCause::_wb_young_gc
150       || cause == GCCause::_wb_full_gc
151       || cause == GCCause::_wb_breakpoint
152       || cause == GCCause::_scavenge_alot;
153 }
154 #endif
155 
156 bool ShenandoahCollectorPolicy::is_requested_gc(GCCause::Cause cause) {
157   return is_explicit_gc(cause) || is_implicit_gc(cause);
158 }
159 
160 bool ShenandoahCollectorPolicy::should_run_full_gc(GCCause::Cause cause) {
161   return is_explicit_gc(cause) ? !ExplicitGCInvokesConcurrent : !ShenandoahImplicitGCInvokesConcurrent;
162 }
163 
164 bool ShenandoahCollectorPolicy::should_handle_requested_gc(GCCause::Cause cause) {
165   assert(is_valid_request(cause), "only requested GCs here: %s", GCCause::to_string(cause));
166 
167   if (DisableExplicitGC) {
168     return !is_explicit_gc(cause);
169   }
170   return true;
171 }
172 
173 void ShenandoahCollectorPolicy::print_gc_stats(outputStream* out) const {
174   out->print_cr("Under allocation pressure, concurrent cycles may cancel, and either continue cycle");
175   out->print_cr("under stop-the-world pause or result in stop-the-world Full GC. Increase heap size,");
176   out->print_cr("tune GC heuristics, set more aggressive pacing delay, or lower allocation rate");
177   out->print_cr("to avoid Degenerated and Full GC cycles. Abbreviated cycles are those which found");
178   out->print_cr("enough regions with no live objects to skip evacuation.");
179   out->cr();
180 
181   size_t completed_gcs = _success_full_gcs + _success_degenerated_gcs + _success_concurrent_gcs + _success_old_gcs;
182   out->print_cr(SIZE_FORMAT_W(5) " Completed GCs", completed_gcs);
183 
184   size_t explicit_requests = 0;
185   size_t implicit_requests = 0;
186   for (int c = 0; c < GCCause::_last_gc_cause; c++) {
187     size_t cause_count = _collection_cause_counts[c];
188     if (cause_count > 0) {
189       auto cause = (GCCause::Cause) c;
190       if (is_explicit_gc(cause)) {
191         explicit_requests += cause_count;
192       } else if (is_implicit_gc(cause)) {
193         implicit_requests += cause_count;
194       }
195       const char* desc = GCCause::to_string(cause);
196       out->print_cr("  " SIZE_FORMAT_W(5) " caused by %s (%.2f%%)", cause_count, desc, percent_of(cause_count, completed_gcs));
197     }
198   }
199 
200   out->cr();
201   out->print_cr(SIZE_FORMAT_W(5) " Successful Concurrent GCs (%.2f%%)", _success_concurrent_gcs, percent_of(_success_concurrent_gcs, completed_gcs));
202   if (ExplicitGCInvokesConcurrent) {
203     out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
204   }
205   if (ShenandoahImplicitGCInvokesConcurrent) {
206     out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
207   }
208   out->print_cr("  " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)",  _abbreviated_concurrent_gcs, percent_of(_abbreviated_concurrent_gcs, _success_concurrent_gcs));
209   out->cr();
210 
211   if (ShenandoahHeap::heap()->mode()->is_generational()) {
212     out->print_cr(SIZE_FORMAT_W(5) " Completed Old GCs (%.2f%%)",        _success_old_gcs, percent_of(_success_old_gcs, completed_gcs));
213     out->print_cr("  " SIZE_FORMAT_W(5) " mixed",                        _mixed_gcs);
214     out->print_cr("  " SIZE_FORMAT_W(5) " interruptions",                _interrupted_old_gcs);
215     out->cr();
216   }
217 
218   size_t degenerated_gcs = _alloc_failure_degenerated_upgrade_to_full + _success_degenerated_gcs;
219   out->print_cr(SIZE_FORMAT_W(5) " Degenerated GCs (%.2f%%)", degenerated_gcs, percent_of(degenerated_gcs, completed_gcs));
220   out->print_cr("  " SIZE_FORMAT_W(5) " upgraded to Full GC (%.2f%%)",          _alloc_failure_degenerated_upgrade_to_full, percent_of(_alloc_failure_degenerated_upgrade_to_full, degenerated_gcs));
221   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_degenerated, percent_of(_alloc_failure_degenerated, degenerated_gcs));
222   out->print_cr("  " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)",                  _abbreviated_degenerated_gcs, percent_of(_abbreviated_degenerated_gcs, degenerated_gcs));
223   for (int c = 0; c < ShenandoahGC::_DEGENERATED_LIMIT; c++) {
224     if (_degen_point_counts[c] > 0) {
225       const char* desc = ShenandoahGC::degen_point_to_string((ShenandoahGC::ShenandoahDegenPoint)c);
226       out->print_cr("    " SIZE_FORMAT_W(5) " happened at %s", _degen_point_counts[c], desc);
227     }
228   }

229   out->cr();
230 
231   out->print_cr(SIZE_FORMAT_W(5) " Full GCs (%.2f%%)", _success_full_gcs, percent_of(_success_full_gcs, completed_gcs));
232   if (!ExplicitGCInvokesConcurrent) {
233     out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
234   }
235   if (!ShenandoahImplicitGCInvokesConcurrent) {
236     out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
237   }
238   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_full, percent_of(_alloc_failure_full, _success_full_gcs));
239   out->print_cr("  " SIZE_FORMAT_W(5) " upgraded from Degenerated GC (%.2f%%)", _alloc_failure_degenerated_upgrade_to_full, percent_of(_alloc_failure_degenerated_upgrade_to_full, _success_full_gcs));
240 }
--- EOF ---