1 /*
2 * Copyright (c) 2013, 2018, 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 package org.graalvm.compiler.replacements;
26
27 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_IGNORED;
28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_IGNORED;
29 import static org.graalvm.compiler.replacements.SnippetTemplate.DEFAULT_REPLACER;
30
31 import java.lang.reflect.Field;
32 import java.util.Arrays;
33
34 import org.graalvm.compiler.api.replacements.Fold;
35 import org.graalvm.compiler.api.replacements.Snippet;
36 import org.graalvm.compiler.api.replacements.Snippet.ConstantParameter;
37 import org.graalvm.compiler.api.replacements.SnippetReflectionProvider;
38 import org.graalvm.compiler.core.common.type.StampFactory;
39 import org.graalvm.compiler.debug.DebugHandlersFactory;
40 import org.graalvm.compiler.debug.GraalError;
41 import org.graalvm.compiler.graph.NodeClass;
42 import org.graalvm.compiler.nodeinfo.NodeInfo;
43 import org.graalvm.compiler.nodes.FixedWithNextNode;
44 import org.graalvm.compiler.nodes.NamedLocationIdentity;
45 import org.graalvm.compiler.nodes.StructuredGraph;
46 import org.graalvm.compiler.nodes.ValueNode;
47 import org.graalvm.compiler.nodes.spi.Lowerable;
48 import org.graalvm.compiler.nodes.spi.LoweringTool;
49 import org.graalvm.compiler.options.OptionValues;
50 import org.graalvm.compiler.phases.util.Providers;
51 import org.graalvm.compiler.replacements.SnippetTemplate.AbstractTemplates;
52 import org.graalvm.compiler.replacements.SnippetTemplate.Arguments;
53 import org.graalvm.compiler.replacements.SnippetTemplate.SnippetInfo;
54 import org.graalvm.compiler.word.ObjectAccess;
55 import jdk.internal.vm.compiler.word.LocationIdentity;
56
57 import jdk.vm.ci.code.TargetDescription;
58 import sun.misc.Unsafe;
59
60 /**
61 * This node can be used to add a counter to the code that will estimate the dynamic number of calls
62 * by adding an increment to the compiled code. This should of course only be used for
63 * debugging/testing purposes.
64 *
65 * A unique counter will be created for each unique name passed to the constructor. Depending on the
66 * value of withContext, the name of the root method is added to the counter's name.
67 */
68 @NodeInfo(cycles = CYCLES_IGNORED, size = SIZE_IGNORED)
69 public class SnippetCounterNode extends FixedWithNextNode implements Lowerable {
70
71 public static final NodeClass<SnippetCounterNode> TYPE = NodeClass.create(SnippetCounterNode.class);
72
73 @Input protected ValueNode increment;
74
75 protected final SnippetCounter counter;
76
77 public SnippetCounterNode(SnippetCounter counter, ValueNode increment) {
78 super(TYPE, StampFactory.forVoid());
79 this.counter = counter;
80 this.increment = increment;
81 }
82
83 public SnippetCounter getCounter() {
84 return counter;
85 }
86
87 public ValueNode getIncrement() {
88 return increment;
89 }
90
91 @NodeIntrinsic
92 public static native void add(@ConstantNodeParameter SnippetCounter counter, int increment);
93
94 public static void increment(@ConstantNodeParameter SnippetCounter counter) {
95 add(counter, 1);
96 }
97
98 @Override
99 public void lower(LoweringTool tool) {
100 if (graph().getGuardsStage().areFrameStatesAtDeopts()) {
101 SnippetCounterSnippets.Templates templates = tool.getReplacements().getSnippetTemplateCache(SnippetCounterSnippets.Templates.class);
102 templates.lower(this, tool);
103 }
104 }
105
106 /**
107 * Add {@link #SNIPPET_COUNTER_LOCATION} to {@code privateLocations} if it isn't already there.
108 *
109 * @param privateLocations
110 * @return a copy of privateLocations with any needed locations added
111 */
112 public static LocationIdentity[] addSnippetCounters(LocationIdentity[] privateLocations) {
113 for (LocationIdentity location : privateLocations) {
114 if (location.equals(SNIPPET_COUNTER_LOCATION)) {
115 return privateLocations;
116 }
117 }
118 LocationIdentity[] result = Arrays.copyOf(privateLocations, privateLocations.length + 1);
119 result[result.length - 1] = SnippetCounterNode.SNIPPET_COUNTER_LOCATION;
120 return result;
121 }
122
123 /**
124 * We do not want to use the {@link LocationIdentity} of the {@link SnippetCounter#value()}
125 * field, so that the usage in snippets is always possible. If a method accesses the counter via
126 * the field and the snippet, the result might not be correct though.
127 */
128 public static final LocationIdentity SNIPPET_COUNTER_LOCATION = NamedLocationIdentity.mutable("SnippetCounter");
129
130 static class SnippetCounterSnippets implements Snippets {
131
132 @Fold
133 static int countOffset() {
134 try {
135 return (int) UNSAFE.objectFieldOffset(SnippetCounter.class.getDeclaredField("value"));
136 } catch (Exception e) {
137 throw new GraalError(e);
138 }
139 }
140
141 @Snippet
142 public static void add(@ConstantParameter SnippetCounter counter, int increment) {
143 long loadedValue = ObjectAccess.readLong(counter, countOffset(), SNIPPET_COUNTER_LOCATION);
144 ObjectAccess.writeLong(counter, countOffset(), loadedValue + increment, SNIPPET_COUNTER_LOCATION);
145 }
146
147 public static class Templates extends AbstractTemplates {
148
149 private final SnippetInfo add = snippet(SnippetCounterSnippets.class, "add", SNIPPET_COUNTER_LOCATION);
150
151 Templates(OptionValues options, Iterable<DebugHandlersFactory> factories, Providers providers, SnippetReflectionProvider snippetReflection, TargetDescription target) {
152 super(options, factories, providers, snippetReflection, target);
153 }
154
155 public void lower(SnippetCounterNode counter, LoweringTool tool) {
156 StructuredGraph graph = counter.graph();
157 Arguments args = new Arguments(add, graph.getGuardsStage(), tool.getLoweringStage());
158 args.addConst("counter", counter.getCounter());
159 args.add("increment", counter.getIncrement());
160
161 template(counter, args).instantiate(providers.getMetaAccess(), counter, DEFAULT_REPLACER, args);
162 }
163 }
164 }
165
166 private static final Unsafe UNSAFE = initUnsafe();
167
168 private static Unsafe initUnsafe() {
169 try {
170 return Unsafe.getUnsafe();
171 } catch (SecurityException se) {
172 try {
173 Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
174 theUnsafe.setAccessible(true);
175 return (Unsafe) theUnsafe.get(Unsafe.class);
176 } catch (Exception e) {
177 throw new RuntimeException("exception while trying to get Unsafe", e);
178 }
179 }
180 }
181 }