--- /dev/null 2015-05-01 18:18:34.004970999 -0400 +++ new/src/share/vm/gc_implementation/g1/g1CollectorState.hpp 2015-05-12 17:05:58.677549509 -0400 @@ -0,0 +1,132 @@ +/* + * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * 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. + * + */ + +#ifndef G1COLLECTORSTATE_HPP +#define G1COLLECTORSTATE_HPP + +#include "utilities/globalDefinitions.hpp" + +class G1CollectorState VALUE_OBJ_CLASS_SPEC { + // Various boolean state variables that indicate + // the phase of the G1 collection. + bool _in_young_gc_mode; + // indicates whether we are in full young or partially young GC mode + bool _gcs_are_young; + bool _last_gc_was_young; + bool _last_young_gc; + + // If initiate_conc_mark_if_possible() is set at the beginning of a + // pause, it is a suggestion that the pause should start a marking + // cycle by doing the initial-mark work. However, it is possible + // that the concurrent marking thread is still finishing up the + // previous marking cycle (e.g., clearing the next marking + // bitmap). If that is the case we cannot start a new cycle and + // we'll have to wait for the concurrent marking thread to finish + // what it is doing. In this case we will postpone the marking cycle + // initiation decision for the next pause. When we eventually decide + // to start a cycle, we will set _during_initial_mark_pause which + // will stay true until the end of the initial-mark pause and it's + // the condition that indicates that a pause is doing the + // initial-mark work. + volatile bool _during_initial_mark_pause; + + // At the end of a pause we check the heap occupancy and we decide + // whether we will start a marking cycle during the next pause. If + // we decide that we want to do that, we will set this parameter to + // true. So, this parameter will stay true between the end of a + // pause and the beginning of a subsequent pause (not necessarily + // the next one, see the comments on the next field) when we decide + // that we will indeed start a marking cycle and do the initial-mark + // work. + volatile bool _initiate_conc_mark_if_possible; + + // NOTE: if some of these are synonyms for others, + // the redundant fields should be eliminated. XXX + bool _during_marking; + bool _mark_in_progress; + bool _in_marking_window; + bool _in_marking_window_im; + + bool _concurrent_cycle_started; + bool _full_collection; + + public: + G1CollectorState() : + _in_young_gc_mode(false), + _gcs_are_young(true), + _last_gc_was_young(false), + _last_young_gc(false), + + _during_initial_mark_pause(false), + _initiate_conc_mark_if_possible(false), + + _during_marking(false), + _mark_in_progress(false), + _in_marking_window(false), + _in_marking_window_im(false), + _concurrent_cycle_started(false), + _full_collection(false) {} + + + // Setters + void set_in_young_gc_mode(bool v) { _in_young_gc_mode = v; } + void set_gcs_are_young(bool v) { _gcs_are_young = v; } + void set_last_gc_was_young(bool v) { _last_gc_was_young = v; } + void set_last_young_gc(bool v) { _last_young_gc = v; } + void set_during_initial_mark_pause(bool v) { _during_initial_mark_pause = v; } + void set_initiate_conc_mark_if_possible(bool v) { _initiate_conc_mark_if_possible = v; } + void set_during_marking(bool v) { _during_marking = v; } + void set_mark_in_progress(bool v) { _mark_in_progress = v; } + void set_in_marking_window(bool v) { _in_marking_window = v; } + void set_in_marking_window_im(bool v) { _in_marking_window_im = v; } + void set_concurrent_cycle_started(bool v) { _concurrent_cycle_started = v; } + void set_full_collection(bool v) { _full_collection = v; } + + // Getters + bool in_young_gc_mode() { return _in_young_gc_mode; } + bool gcs_are_young() { return _gcs_are_young; } + bool last_gc_was_young() { return _last_gc_was_young; } + bool last_young_gc() { return _last_young_gc; } + bool during_initial_mark_pause() { return _during_initial_mark_pause; } + bool initiate_conc_mark_if_possible() { return _initiate_conc_mark_if_possible; } + bool during_marking() { return _during_marking; } + bool mark_in_progress() { return _mark_in_progress; } + bool in_marking_window() { return _in_marking_window; } + bool in_marking_window_im() { return _in_marking_window_im; } + bool concurrent_cycle_started() { return _concurrent_cycle_started; } + bool full_collection() { return _full_collection; } + + // Composite booleans (clients worry about flickering) + bool during_concurrent_mark() { + return (_in_marking_window && !_in_marking_window_im); + } + + bool should_propagate() { // XXX should have a more suitable state name or abstraction for this + return (_last_young_gc && !_in_marking_window); + } + +}; + +#endif /* G1COLLECTORSTATE_HPP */ +