1 /*
   2  * Copyright (c) 2013, 2018, Red Hat, Inc. All rights reserved.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #include "precompiled.hpp"
  25 
  26 #include "gc/shenandoah/shenandoahCollectorPolicy.hpp"
  27 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
  28 #include "runtime/os.hpp"
  29 
  30 ShenandoahCollectorPolicy::ShenandoahCollectorPolicy() :
  31   _success_concurrent_gcs(0),
  32   _success_degenerated_gcs(0),
  33   _success_full_gcs(0),
  34   _alloc_failure_degenerated(0),
  35   _alloc_failure_degenerated_upgrade_to_full(0),
  36   _alloc_failure_full(0),
  37   _explicit_concurrent(0),
  38   _explicit_full(0),
  39   _implicit_concurrent(0),
  40   _implicit_full(0),
  41   _cycle_counter(0) {
  42 
  43   Copy::zero_to_bytes(_degen_points, sizeof(size_t) * ShenandoahHeap::_DEGENERATED_LIMIT);
  44 
  45   ShenandoahHeapRegion::setup_sizes(initial_heap_byte_size(), max_heap_byte_size());
  46 
  47   initialize_all();
  48 
  49   _tracer = new (ResourceObj::C_HEAP, mtGC) ShenandoahTracer();
  50 
  51 }
  52 
  53 void ShenandoahCollectorPolicy::initialize_alignments() {
  54   // This is expected by our algorithm for ShenandoahHeap::heap_region_containing().
  55   size_t align = ShenandoahHeapRegion::region_size_bytes();
  56   if (UseLargePages) {
  57     align = MAX2(align, os::large_page_size());
  58   }
  59   _space_alignment = align;
  60   _heap_alignment = align;
  61 }
  62 
  63 void ShenandoahCollectorPolicy::record_explicit_to_concurrent() {
  64   _explicit_concurrent++;
  65 }
  66 
  67 void ShenandoahCollectorPolicy::record_explicit_to_full() {
  68   _explicit_full++;
  69 }
  70 
  71 void ShenandoahCollectorPolicy::record_implicit_to_concurrent() {
  72   _implicit_concurrent++;
  73 }
  74 
  75 void ShenandoahCollectorPolicy::record_implicit_to_full() {
  76   _implicit_full++;
  77 }
  78 
  79 void ShenandoahCollectorPolicy::record_alloc_failure_to_full() {
  80   _alloc_failure_full++;
  81 }
  82 
  83 void ShenandoahCollectorPolicy::record_alloc_failure_to_degenerated(ShenandoahHeap::ShenandoahDegenPoint point) {
  84   assert(point < ShenandoahHeap::_DEGENERATED_LIMIT, "sanity");
  85   _alloc_failure_degenerated++;
  86   _degen_points[point]++;
  87 }
  88 
  89 void ShenandoahCollectorPolicy::record_degenerated_upgrade_to_full() {
  90   _alloc_failure_degenerated_upgrade_to_full++;
  91 }
  92 
  93 void ShenandoahCollectorPolicy::record_success_concurrent() {
  94   _success_concurrent_gcs++;
  95 }
  96 
  97 void ShenandoahCollectorPolicy::record_success_degenerated() {
  98   _success_degenerated_gcs++;
  99 }
 100 
 101 void ShenandoahCollectorPolicy::record_success_full() {
 102   _success_full_gcs++;
 103 }
 104 
 105 size_t ShenandoahCollectorPolicy::cycle_counter() const {
 106   return _cycle_counter;
 107 }
 108 
 109 void ShenandoahCollectorPolicy::record_cycle_start() {
 110   _cycle_counter++;
 111 }
 112 
 113 void ShenandoahCollectorPolicy::record_shutdown() {
 114   _in_shutdown.set();
 115 }
 116 
 117 bool ShenandoahCollectorPolicy::is_at_shutdown() {
 118   return _in_shutdown.is_set();
 119 }
 120 
 121 void ShenandoahCollectorPolicy::print_gc_stats(outputStream* out) const {
 122   out->print_cr("Under allocation pressure, concurrent cycles may cancel, and either continue cycle");
 123   out->print_cr("under stop-the-world pause or result in stop-the-world Full GC. Increase heap size,");
 124   out->print_cr("tune GC heuristics, set more aggressive pacing delay, or lower allocation rate");
 125   out->print_cr("to avoid Degenerated and Full GC cycles.");
 126   out->cr();
 127 
 128   out->print_cr(SIZE_FORMAT_W(5) " successful concurrent GCs",         _success_concurrent_gcs);
 129   out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly",           _explicit_concurrent);
 130   out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly",           _implicit_concurrent);
 131   out->cr();
 132 
 133   out->print_cr(SIZE_FORMAT_W(5) " Degenerated GCs",                   _success_degenerated_gcs);
 134   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure", _alloc_failure_degenerated);
 135   for (int c = 0; c < ShenandoahHeap::_DEGENERATED_LIMIT; c++) {
 136     if (_degen_points[c] > 0) {
 137       const char* desc = ShenandoahHeap::degen_point_to_string((ShenandoahHeap::ShenandoahDegenPoint)c);
 138       out->print_cr("    " SIZE_FORMAT_W(5) " happened at %s",         _degen_points[c], desc);
 139     }
 140   }
 141   out->print_cr("  " SIZE_FORMAT_W(5) " upgraded to Full GC",          _alloc_failure_degenerated_upgrade_to_full);
 142   out->cr();
 143 
 144   out->print_cr(SIZE_FORMAT_W(5) " Full GCs",                          _success_full_gcs + _alloc_failure_degenerated_upgrade_to_full);
 145   out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly",           _explicit_full);
 146   out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly",           _implicit_full);
 147   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure", _alloc_failure_full);
 148   out->print_cr("  " SIZE_FORMAT_W(5) " upgraded from Degenerated GC", _alloc_failure_degenerated_upgrade_to_full);
 149 }