| /* |
| * Copyright (c) 2018, Red Hat, Inc. All rights reserved. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| |
| #include "gc/shenandoah/heuristics/shenandoahAggressiveHeuristics.hpp" |
| #include "gc/shenandoah/shenandoahCollectionSet.hpp" |
| #include "gc/shenandoah/shenandoahHeapRegion.inline.hpp" |
| #include "logging/log.hpp" |
| #include "logging/logTag.hpp" |
| #include "runtime/os.hpp" |
| |
| ShenandoahAggressiveHeuristics::ShenandoahAggressiveHeuristics() : ShenandoahHeuristics() { |
| // Do not shortcut evacuation |
| SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahImmediateThreshold, 100); |
| |
| // Aggressive evacuates everything, so it needs as much evac space as it can get |
| SHENANDOAH_ERGO_ENABLE_FLAG(ShenandoahEvacReserveOverflow); |
| |
| // If class unloading is globally enabled, aggressive does unloading even with |
| // concurrent cycles. |
| if (ClassUnloading) { |
| SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahUnloadClassesFrequency, 1); |
| } |
| } |
| |
| void ShenandoahAggressiveHeuristics::choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset, |
| RegionData* data, size_t size, |
| size_t free) { |
| for (size_t idx = 0; idx < size; idx++) { |
| ShenandoahHeapRegion* r = data[idx]._region; |
| if (r->garbage() > 0) { |
| cset->add_region(r); |
| } |
| } |
| } |
| |
| bool ShenandoahAggressiveHeuristics::should_start_gc() const { |
| log_info(gc)("Trigger: Start next cycle immediately"); |
| return true; |
| } |
| |
| bool ShenandoahAggressiveHeuristics::should_process_references() { |
| if (!can_process_references()) return false; |
| // Randomly process refs with 50% chance. |
| return (os::random() & 1) == 1; |
| } |
| |
| bool ShenandoahAggressiveHeuristics::should_unload_classes() { |
| if (!can_unload_classes_normal()) return false; |
| if (has_metaspace_oom()) return true; |
| // Randomly unload classes with 50% chance. |
| return (os::random() & 1) == 1; |
| } |