1 /* 2 * Copyright (c) 2001, 2016, 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_SOFTREFPOLICY_HPP 26 #define SHARE_VM_GC_SHARED_SOFTREFPOLICY_HPP 27 28 #include "memory/allocation.hpp" 29 30 class SoftRefPolicy { 31 private: 32 // Set to true when policy wants soft refs cleared. 33 // Reset to false by gc after it clears all soft refs. 34 bool _should_clear_all_soft_refs; 35 36 // Set to true by the GC if the just-completed gc cleared all 37 // softrefs. This is set to true whenever a gc clears all softrefs, and 38 // set to false each time gc returns to the mutator. For example, in the 39 // ParallelScavengeHeap case the latter would be done toward the end of 40 // mem_allocate() where it returns op.result() 41 bool _all_soft_refs_clear; 42 43 public: 44 SoftRefPolicy(); 45 46 bool should_clear_all_soft_refs() { return _should_clear_all_soft_refs; } 47 void set_should_clear_all_soft_refs(bool v) { _should_clear_all_soft_refs = v; } 48 // Returns the current value of _should_clear_all_soft_refs. 49 // _should_clear_all_soft_refs is set to false as a side effect. 50 bool use_should_clear_all_soft_refs(bool v); 51 bool all_soft_refs_clear() { return _all_soft_refs_clear; } 52 void set_all_soft_refs_clear(bool v) { _all_soft_refs_clear = v; } 53 54 // Called by the GC after Soft Refs have been cleared to indicate 55 // that the request in _should_clear_all_soft_refs has been fulfilled. 56 virtual void cleared_all_soft_refs(); 57 }; 58 59 class ClearedAllSoftRefs : public StackObj { 60 bool _clear_all_soft_refs; 61 SoftRefPolicy* _soft_ref_policy; 62 public: 63 ClearedAllSoftRefs(bool clear_all_soft_refs, SoftRefPolicy* soft_ref_policy) : 64 _clear_all_soft_refs(clear_all_soft_refs), 65 _soft_ref_policy(soft_ref_policy) {} 66 67 ~ClearedAllSoftRefs() { 68 if (_clear_all_soft_refs) { 69 _soft_ref_policy->cleared_all_soft_refs(); 70 } 71 } 72 73 bool should_clear() { return _clear_all_soft_refs; } 74 }; 75 76 #endif // SHARE_VM_GC_SHARED_SOFTREFPOLICY_HPP