1 /*
2 * Copyright (c) 1997, 2017, 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 #include "precompiled.hpp"
26 #include "interpreter/invocationCounter.hpp"
27 #include "runtime/frame.hpp"
28 #include "runtime/handles.inline.hpp"
29
30
31 // Implementation of InvocationCounter
32
33 void InvocationCounter::init() {
34 _counter = 0; // reset all the bits, including the sticky carry
35 reset();
36 }
37
38 void InvocationCounter::reset() {
39 // Only reset the state and don't make the method look like it's never
40 // been executed
41 set_state(wait_for_compile);
42 }
43
44 void InvocationCounter::set_carry() {
45 set_carry_flag();
46 // The carry bit now indicates that this counter had achieved a very
47 // large value. Now reduce the value, so that the method can be
48 // executed many more times before re-entering the VM.
49 int old_count = count();
50 int new_count = MIN2(old_count, (int) (CompileThreshold / 2));
51 // prevent from going to zero, to distinguish from never-executed methods
52 if (new_count == 0) new_count = 1;
53 if (old_count != new_count) set(state(), new_count);
54 }
55
56 void InvocationCounter::set_state(State state) {
57 assert(0 <= state && state < number_of_states, "illegal state");
58 int init = _init[state];
59 // prevent from going to zero, to distinguish from never-executed methods
60 if (init == 0 && count() > 0) init = 1;
61 int carry = (_counter & carry_mask); // the carry bit is sticky
62 _counter = (init << number_of_noncount_bits) | carry | state;
63 }
64
65
66 void InvocationCounter::print() {
67 tty->print_cr("invocation count: up = %d, limit = %d, carry = %s, state = %s",
68 count(), limit(),
69 carry() ? "true" : "false",
70 state_as_string(state()));
71 }
72
73 void InvocationCounter::print_short() {
74 tty->print(" [%d%s;%s]", count(), carry()?"+carry":"", state_as_short_string(state()));
75 }
76
77 // Initialization
78
79 int InvocationCounter::_init [InvocationCounter::number_of_states];
80 InvocationCounter::Action InvocationCounter::_action[InvocationCounter::number_of_states];
81 int InvocationCounter::InterpreterInvocationLimit;
82 int InvocationCounter::InterpreterBackwardBranchLimit;
83 int InvocationCounter::InterpreterProfileLimit;
84
85
86 const char* InvocationCounter::state_as_string(State state) {
87 switch (state) {
88 case wait_for_nothing : return "wait_for_nothing";
89 case wait_for_compile : return "wait_for_compile";
90 default:
91 ShouldNotReachHere();
92 return NULL;
93 }
94 }
95
96 const char* InvocationCounter::state_as_short_string(State state) {
97 switch (state) {
98 case wait_for_nothing : return "not comp.";
99 case wait_for_compile : return "compileable";
100 default:
101 ShouldNotReachHere();
102 return NULL;
103 }
104 }
105
106
107 static address do_nothing(methodHandle method, TRAPS) {
108 // dummy action for inactive invocation counters
109 MethodCounters* mcs = method->method_counters();
110 assert(mcs != NULL, "");
111 mcs->invocation_counter()->set_carry();
112 mcs->invocation_counter()->set_state(InvocationCounter::wait_for_nothing);
113 return NULL;
114 }
115
116
117 static address do_decay(methodHandle method, TRAPS) {
118 // decay invocation counters so compilation gets delayed
119 MethodCounters* mcs = method->method_counters();
120 assert(mcs != NULL, "");
121 mcs->invocation_counter()->decay();
122 return NULL;
123 }
124
125
126 void InvocationCounter::def(State state, int init, Action action) {
127 assert(0 <= state && state < number_of_states, "illegal state");
128 assert(0 <= init && init < count_limit, "initial value out of range");
129 _init [state] = init;
130 _action[state] = action;
131 }
132
133 address dummy_invocation_counter_overflow(methodHandle m, TRAPS) {
134 ShouldNotReachHere();
135 return NULL;
136 }
137
138 void InvocationCounter::reinitialize(bool delay_overflow) {
139 // define states
140 guarantee((int)number_of_states <= (int)state_limit, "adjust number_of_state_bits");
141 def(wait_for_nothing, 0, do_nothing);
142 if (delay_overflow) {
143 def(wait_for_compile, 0, do_decay);
144 } else {
145 def(wait_for_compile, 0, dummy_invocation_counter_overflow);
146 }
147
148 InterpreterInvocationLimit = CompileThreshold << number_of_noncount_bits;
149 InterpreterProfileLimit = ((CompileThreshold * InterpreterProfilePercentage) / 100)<< number_of_noncount_bits;
150
151 // When methodData is collected, the backward branch limit is compared against a
152 // methodData counter, rather than an InvocationCounter. In the former case, we
153 // don't need the shift by number_of_noncount_bits, but we do need to adjust
154 // the factor by which we scale the threshold.
155 if (ProfileInterpreter) {
156 InterpreterBackwardBranchLimit = (CompileThreshold * (OnStackReplacePercentage - InterpreterProfilePercentage)) / 100;
157 } else {
158 InterpreterBackwardBranchLimit = ((CompileThreshold * OnStackReplacePercentage) / 100) << number_of_noncount_bits;
159 }
160
161 assert(0 <= InterpreterBackwardBranchLimit,
162 "OSR threshold should be non-negative");
163 assert(0 <= InterpreterProfileLimit &&
164 InterpreterProfileLimit <= InterpreterInvocationLimit,
165 "profile threshold should be less than the compilation threshold "
166 "and non-negative");
167 }
168
169 void invocationCounter_init() {
170 InvocationCounter::reinitialize(DelayCompilationDuringStartup);
171 }