1 /*
2 * Copyright (c) 1997, 2010, 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 "incls/_precompiled.incl"
26 # include "incls/_invocationCounter.cpp.incl"
27
28
29 // Implementation of InvocationCounter
30
31 void InvocationCounter::init() {
32 _counter = 0; // reset all the bits, including the sticky carry
33 reset();
34 }
35
36 void InvocationCounter::reset() {
37 // Only reset the state and don't make the method look like it's never
38 // been executed
39 set_state(wait_for_compile);
40 }
41
42 void InvocationCounter::set_carry() {
43 set_carry_flag();
44 // The carry bit now indicates that this counter had achieved a very
45 // large value. Now reduce the value, so that the method can be
46 // executed many more times before re-entering the VM.
47 int old_count = count();
48 int new_count = MIN2(old_count, (int) (CompileThreshold / 2));
49 // prevent from going to zero, to distinguish from never-executed methods
50 if (new_count == 0) new_count = 1;
51 if (old_count != new_count) set(state(), new_count);
52 }
53
54 void InvocationCounter::set_state(State state) {
55 assert(0 <= state && state < number_of_states, "illegal state");
56 int init = _init[state];
57 // prevent from going to zero, to distinguish from never-executed methods
58 if (init == 0 && count() > 0) init = 1;
59 int carry = (_counter & carry_mask); // the carry bit is sticky
60 _counter = (init << number_of_noncount_bits) | carry | state;
61 }
62
63
64 void InvocationCounter::print() {
65 tty->print_cr("invocation count: up = %d, limit = %d, carry = %s, state = %s",
66 count(), limit(),
67 carry() ? "true" : "false",
68 state_as_string(state()));
69 }
70
71 void InvocationCounter::print_short() {
72 tty->print(" [%d%s;%s]", count(), carry()?"+carry":"", state_as_short_string(state()));
73 }
74
75 // Initialization
76
77 int InvocationCounter::_init [InvocationCounter::number_of_states];
78 InvocationCounter::Action InvocationCounter::_action[InvocationCounter::number_of_states];
79 int InvocationCounter::InterpreterInvocationLimit;
80 int InvocationCounter::InterpreterBackwardBranchLimit;
81 int InvocationCounter::InterpreterProfileLimit;
82
83
84 const char* InvocationCounter::state_as_string(State state) {
85 switch (state) {
86 case wait_for_nothing : return "wait_for_nothing";
87 case wait_for_compile : return "wait_for_compile";
88 }
89 ShouldNotReachHere();
90 return NULL;
91 }
92
93 const char* InvocationCounter::state_as_short_string(State state) {
94 switch (state) {
95 case wait_for_nothing : return "not comp.";
96 case wait_for_compile : return "compileable";
97 }
98 ShouldNotReachHere();
99 return NULL;
100 }
101
102
103 static address do_nothing(methodHandle method, TRAPS) {
104 // dummy action for inactive invocation counters
105 method->invocation_counter()->set_carry();
106 method->invocation_counter()->set_state(InvocationCounter::wait_for_nothing);
107 return NULL;
108 }
109
110
111 static address do_decay(methodHandle method, TRAPS) {
112 // decay invocation counters so compilation gets delayed
113 method->invocation_counter()->decay();
114 return NULL;
115 }
116
117
118 void InvocationCounter::def(State state, int init, Action action) {
119 assert(0 <= state && state < number_of_states, "illegal state");
120 assert(0 <= init && init < count_limit, "initial value out of range");
121 _init [state] = init;
122 _action[state] = action;
123 }
124
125 address dummy_invocation_counter_overflow(methodHandle m, TRAPS) {
126 ShouldNotReachHere();
127 return NULL;
128 }
129
130 void InvocationCounter::reinitialize(bool delay_overflow) {
131 // define states
132 guarantee((int)number_of_states <= (int)state_limit, "adjust number_of_state_bits");
133 def(wait_for_nothing, 0, do_nothing);
134 if (delay_overflow) {
135 def(wait_for_compile, 0, do_decay);
136 } else {
137 def(wait_for_compile, 0, dummy_invocation_counter_overflow);
138 }
139
140 InterpreterInvocationLimit = CompileThreshold << number_of_noncount_bits;
141 InterpreterProfileLimit = ((CompileThreshold * InterpreterProfilePercentage) / 100)<< number_of_noncount_bits;
142
143 // When methodData is collected, the backward branch limit is compared against a
144 // methodData counter, rather than an InvocationCounter. In the former case, we
145 // don't need the shift by number_of_noncount_bits, but we do need to adjust
146 // the factor by which we scale the threshold.
147 if (ProfileInterpreter) {
148 InterpreterBackwardBranchLimit = (CompileThreshold * (OnStackReplacePercentage - InterpreterProfilePercentage)) / 100;
149 } else {
150 InterpreterBackwardBranchLimit = ((CompileThreshold * OnStackReplacePercentage) / 100) << number_of_noncount_bits;
151 }
152
153 assert(0 <= InterpreterBackwardBranchLimit,
154 "OSR threshold should be non-negative");
155 assert(0 <= InterpreterProfileLimit &&
156 InterpreterProfileLimit <= InterpreterInvocationLimit,
157 "profile threshold should be less than the compilation threshold "
158 "and non-negative");
159 }
160
161 void invocationCounter_init() {
162 InvocationCounter::reinitialize(DelayCompilationDuringStartup);
163 }