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comparison truffle/com.oracle.truffle.api.profiles/src/com/oracle/truffle/api/profiles/BranchProfile.java @ 22503:828c67903db2

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Moving profiles into their own project to ensure the core API doesn't reference these utility classes.
author Jaroslav Tulach <jaroslav.tulach@oracle.com>
date Thu, 17 Dec 2015 10:01:38 +0100
parents truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/profiles/BranchProfile.java@a63bda98cfdb
children d80a5ff56f51
comparison
equal deleted inserted replaced
22502:d2b4fe945c23 22503:828c67903db2
1 /*
2 * Copyright (c) 2013, 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package com.oracle.truffle.api.profiles;
26
27 import com.oracle.truffle.api.CompilerDirectives;
28 import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
29 import com.oracle.truffle.api.Truffle;
30
31 /**
32 * <p>
33 * BranchProfiles are profiles to speculate on branches that are unlikely to be visited. If the
34 * {@link #enter()} method is invoked first the optimized code is invalidated and the branch where
35 * {@link #enter()} is invoked is enabled for compilation. Otherwise if the {@link #enter()} method
36 * was never invoked the branch will not get compiled.
37 * </p>
38 *
39 * <p>
40 * <b> Usage example: </b>
41 *
42 * <pre>
43 * class SampleNode extends Node {
44 *
45 * final BranchProfile errorProfile = BranchProfile.create();
46 *
47 * void execute(int value) {
48 * if (value == Integer.MAX_VALUE) {
49 * errorProfile.enter();
50 * throw new Error(&quot;Invalid input value&quot;)
51 * }
52 * return value;
53 * }
54 * }
55 * </pre>
56 *
57 * {@inheritDoc}
58 *
59 * @see BranchProfile#enter()
60 */
61 public abstract class BranchProfile extends Profile {
62
63 BranchProfile() {
64 }
65
66 /**
67 * Call when an unlikely branch is entered.
68 */
69 public abstract void enter();
70
71 /**
72 * @deprecated it is not reliable when profiling is turned off.
73 */
74 @Deprecated
75 public abstract boolean isVisited();
76
77 /**
78 * Call to create a new instance of a branch profile.
79 */
80 public static BranchProfile create() {
81 if (Truffle.getRuntime().isProfilingEnabled()) {
82 return Enabled.create0();
83 } else {
84 return Disabled.INSTANCE;
85 }
86 }
87
88 static final class Enabled extends BranchProfile {
89
90 @CompilationFinal private boolean visited;
91
92 @Override
93 public void enter() {
94 if (!visited) {
95 CompilerDirectives.transferToInterpreterAndInvalidate();
96 visited = true;
97 }
98 }
99
100 @SuppressWarnings("deprecation")
101 @Override
102 public boolean isVisited() {
103 return visited;
104 }
105
106 @Override
107 public String toString() {
108 return toString(BranchProfile.class, !visited, false, "VISITED");
109 }
110
111 /* Needed for lazy class loading. */
112 static BranchProfile create0() {
113 return new Enabled();
114 }
115 }
116
117 static final class Disabled extends BranchProfile {
118
119 static final BranchProfile INSTANCE = new Disabled();
120
121 @Override
122 protected Object clone() {
123 return INSTANCE;
124 }
125
126 @Override
127 public void enter() {
128 }
129
130 @SuppressWarnings("deprecation")
131 @Override
132 public boolean isVisited() {
133 return true;
134 }
135
136 @Override
137 public String toString() {
138 return toStringDisabled(BranchProfile.class);
139 }
140
141 }
142
143 }