1 /* 2 * Copyright (c) 2013, 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_OOPS_METHODCOUNTERS_HPP 26 #define SHARE_VM_OOPS_METHODCOUNTERS_HPP 27 28 #include "oops/metadata.hpp" 29 #include "interpreter/invocationCounter.hpp" 30 31 class MethodCounters: public MetaspaceObj { 32 friend class VMStructs; 33 private: 34 int _interpreter_invocation_count; // Count of times invoked (reused as prev_event_count in tiered) 35 u2 _interpreter_throwout_count; // Count of times method was exited via exception while interpreting 36 u2 _number_of_breakpoints; // fullspeed debugging support 37 InvocationCounter _invocation_counter; // Incremented before each activation of the method - used to trigger frequency-based optimizations 38 InvocationCounter _backedge_counter; // Incremented before each backedge taken - used to trigger frequencey-based optimizations 39 // NMethod age is a counter for warm methods detection in the code cache sweeper. 40 // The counter is reset by the sweeper and is decremented by some of the compiled 41 // code. The counter values are interpreted as follows: 42 // 1. (HotMethodDetection..INT_MAX] - initial value, no counters inserted 43 // 2. (1..HotMethodDetectionLimit) - the method is warm, the counter is used 44 // to figure out which methods can be flushed. 45 // 3. (INT_MIN..0] - method is hot and will deopt and get 46 // recompiled without the counters 47 int _nmethod_age; 48 49 #ifdef TIERED 50 float _rate; // Events (invocation and backedge counter increments) per millisecond 51 jlong _prev_time; // Previous time the rate was acquired 52 #endif 53 54 MethodCounters() : _interpreter_invocation_count(0), 55 _interpreter_throwout_count(0), 56 _number_of_breakpoints(0), 57 _nmethod_age(INT_MAX) 58 #ifdef TIERED 59 , _rate(0), 60 _prev_time(0) 61 #endif 62 { 63 invocation_counter()->init(); 64 backedge_counter()->init(); 65 66 if (StressCodeAging) { 67 set_nmethod_age(HotMethodDetectionLimit); 68 } 69 } 70 71 public: 72 static MethodCounters* allocate(ClassLoaderData* loader_data, TRAPS); 73 74 void deallocate_contents(ClassLoaderData* loader_data) {} 75 DEBUG_ONLY(bool on_stack() { return false; }) // for template 76 77 static int size() { return sizeof(MethodCounters) / wordSize; } 78 79 bool is_klass() const { return false; } 80 81 void clear_counters(); 82 83 int interpreter_invocation_count() { 84 return _interpreter_invocation_count; 85 } 86 void set_interpreter_invocation_count(int count) { 87 _interpreter_invocation_count = count; 88 } 89 int increment_interpreter_invocation_count() { 90 return ++_interpreter_invocation_count; 91 } 92 93 void interpreter_throwout_increment() { 94 if (_interpreter_throwout_count < 65534) { 95 _interpreter_throwout_count++; 96 } 97 } 98 int interpreter_throwout_count() const { 99 return _interpreter_throwout_count; 100 } 101 void set_interpreter_throwout_count(int count) { 102 _interpreter_throwout_count = count; 103 } 104 105 u2 number_of_breakpoints() const { return _number_of_breakpoints; } 106 void incr_number_of_breakpoints() { ++_number_of_breakpoints; } 107 void decr_number_of_breakpoints() { --_number_of_breakpoints; } 108 void clear_number_of_breakpoints() { _number_of_breakpoints = 0; } 109 110 #ifdef TIERED 111 jlong prev_time() const { return _prev_time; } 112 void set_prev_time(jlong time) { _prev_time = time; } 113 float rate() const { return _rate; } 114 void set_rate(float rate) { _rate = rate; } 115 #endif 116 117 // invocation counter 118 InvocationCounter* invocation_counter() { return &_invocation_counter; } 119 InvocationCounter* backedge_counter() { return &_backedge_counter; } 120 121 int nmethod_age() { 122 return _nmethod_age; 123 } 124 void set_nmethod_age(int age) { 125 _nmethod_age = age; 126 } 127 void reset_nmethod_age() { 128 set_nmethod_age(HotMethodDetectionLimit); 129 } 130 131 static bool is_nmethod_hot(int age) { return age <= 0; } 132 static bool is_nmethod_warm(int age) { return age < HotMethodDetectionLimit; } 133 static bool is_nmethod_age_unset(int age) { return age > HotMethodDetectionLimit; } 134 135 static ByteSize nmethod_age_offset() { 136 return byte_offset_of(MethodCounters, _nmethod_age); 137 } 138 139 static ByteSize interpreter_invocation_counter_offset() { 140 return byte_offset_of(MethodCounters, _interpreter_invocation_count); 141 } 142 143 static ByteSize invocation_counter_offset() { 144 return byte_offset_of(MethodCounters, _invocation_counter); 145 } 146 147 static ByteSize backedge_counter_offset() { 148 return byte_offset_of(MethodCounters, _backedge_counter); 149 } 150 151 static int interpreter_invocation_counter_offset_in_bytes() { 152 return offset_of(MethodCounters, _interpreter_invocation_count); 153 } 154 155 }; 156 #endif //SHARE_VM_OOPS_METHODCOUNTERS_HPP