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 class G1NewTracer; 33 34 // Manages the decision about the threshold when concurrent marking should start. 35 class G1IHOPControl : public CHeapObj<mtGC> { 36 protected: 37 double _ihop_percent; 38 size_t _target_occupancy; 39 40 // Initialize an instance with the initial IHOP value in percent and the target 41 // occupancy. The target occupancy is the number of bytes when marking should 42 // be finished and reclaim started. 43 G1IHOPControl(double initial_ihop_percent, size_t target_occupancy); 44 public: 45 virtual ~G1IHOPControl() { } 46 47 // Get the current marking threshold in bytes. 48 virtual size_t get_conc_mark_start_threshold() = 0; 49 50 // Update information about recent time during which allocations happened, 51 // how many allocations happened and an additional safety buffer. 52 virtual void update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) = 0; 53 // Update the time from the end of initial mark to the first mixed gc. 54 virtual void update_time_to_mixed(double marking_length_s) = 0; 55 56 virtual void print() = 0; 57 virtual void send_event(G1NewTracer* tracer) = 0; 58 }; 59 60 class G1StaticIHOPControl : public G1IHOPControl { 61 double _last_allocation_time_s; 62 size_t _last_allocated_bytes; 63 double _last_marking_length_s; 64 public: 65 G1StaticIHOPControl(double ihop_percent, size_t target_occupancy); 66 67 size_t get_conc_mark_start_threshold() { return (size_t) (_ihop_percent * _target_occupancy / 100.0); } 68 69 virtual void update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) { 70 assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s); 71 _last_allocation_time_s = allocation_time_s; 72 _last_allocated_bytes = allocated_bytes; 73 } 74 75 virtual void update_time_to_mixed(double marking_length_s) { 76 assert(marking_length_s > 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s); 77 _last_marking_length_s = marking_length_s; 78 } 79 80 virtual void print(); 81 virtual void send_event(G1NewTracer* tracer); 82 #ifndef PRODUCT 83 static void test(); 84 #endif 85 }; 86 87 class G1AdaptiveIHOPControl : public G1IHOPControl { 88 G1Predictions const * _predictor; 89 90 TruncatedSeq _marking_times_s; 91 TruncatedSeq _allocation_rate_s; 92 93 size_t _last_allocation_bytes; // Most recent mutator allocation since last GC. 94 size_t _prev_unrestrained_young_size; 95 96 size_t _current_threshold; 97 98 // Updates _current_threshold according to internal state. 99 void recalculate(); 100 101 bool have_enough_data_for_prediction() const; 102 public: 103 G1AdaptiveIHOPControl(double ihop_percent, size_t initial_target_occupancy, G1Predictions const* predictor); 104 105 virtual void set_target_occupancy(size_t target_occupancy); 106 107 virtual size_t get_conc_mark_start_threshold(); 108 109 virtual void update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size); 110 virtual void update_time_to_mixed(double marking_length_s); 111 112 virtual void print(); 113 virtual void send_event(G1NewTracer* tracer); 114 #ifndef PRODUCT 115 static void test(); 116 #endif 117 }; 118 119 #endif // SHARE_VM_GC_G1_G1IHOPCONTROL_HPP