1 /* 2 * Copyright (c) 2015, 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_G1_G1IHOPCONTROL_HPP 26 #define SHARE_VM_GC_G1_G1IHOPCONTROL_HPP 27 28 #include "memory/allocation.hpp" 29 #include "utilities/numberSeq.hpp" 30 31 class G1Predictions; 32 33 // Manages the decision about the threshold when concurrent marking should start. 34 class G1IHOPControl : public CHeapObj<mtGC> { 35 protected: 36 double _ihop_percent; 37 size_t _target_occupancy; 38 39 // Initialize an instance with the initial IHOP value in percent and the target 40 // occupancy. The target occupancy is the number of bytes when marking should 41 // be finished and reclaim started. 42 G1IHOPControl(double initial_ihop_percent, size_t target_occupancy); 43 public: 44 virtual ~G1IHOPControl() { } 45 46 // Get the current marking threshold in bytes. 47 virtual size_t get_conc_mark_start_threshold() = 0; 48 49 // Update information about recent time during which allocations happened, 50 // how many allocations happened and an additional safety buffer. 51 virtual void update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) = 0; 52 // Update the time from the end of initial mark to the first mixed gc. 53 virtual void update_time_to_mixed(double marking_length_s) = 0; 54 55 virtual void print() = 0; 56 }; 57 58 class G1StaticIHOPControl : public G1IHOPControl { 59 double _last_allocation_time_s; 60 size_t _last_allocated_bytes; 61 double _last_marking_length_s; 62 public: 63 G1StaticIHOPControl(double ihop_percent, size_t target_occupancy) : 64 G1IHOPControl(ihop_percent, target_occupancy), 65 _last_allocation_time_s(0.0), 66 _last_allocated_bytes(0), 67 _last_marking_length_s(0.0) { } 68 69 size_t get_conc_mark_start_threshold() { return (size_t) (_ihop_percent * _target_occupancy / 100.0); } 70 71 virtual void update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) { 72 assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s); 73 _last_allocation_time_s = allocation_time_s; 74 _last_allocated_bytes = allocated_bytes; 75 } 76 77 virtual void update_time_to_mixed(double marking_length_s) { 78 assert(marking_length_s > 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s); 79 _last_marking_length_s = marking_length_s; 80 } 81 82 virtual void print(); 83 #ifndef PRODUCT 84 static void test(); 85 #endif 86 }; 87 88 #endif // SHARE_VM_GC_G1_G1IHOPCONTROL_HPP