1 /*
2 * Copyright (c) 2013, 2016, 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 package org.graalvm.compiler.replacements;
24
25 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_IGNORED;
26 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_IGNORED;
27 import static org.graalvm.compiler.replacements.SnippetTemplate.DEFAULT_REPLACER;
28
29 import java.lang.reflect.Field;
30 import java.util.Arrays;
31
32 import org.graalvm.compiler.api.replacements.Fold;
33 import org.graalvm.compiler.api.replacements.Snippet;
34 import org.graalvm.compiler.api.replacements.Snippet.ConstantParameter;
35 import org.graalvm.compiler.api.replacements.SnippetReflectionProvider;
36 import org.graalvm.compiler.core.common.type.StampFactory;
37 import org.graalvm.compiler.debug.DebugHandlersFactory;
38 import org.graalvm.compiler.debug.GraalError;
39 import org.graalvm.compiler.graph.NodeClass;
40 import org.graalvm.compiler.nodeinfo.NodeInfo;
41 import org.graalvm.compiler.nodes.FixedWithNextNode;
42 import org.graalvm.compiler.nodes.NamedLocationIdentity;
43 import org.graalvm.compiler.nodes.StructuredGraph;
44 import org.graalvm.compiler.nodes.ValueNode;
45 import org.graalvm.compiler.nodes.spi.Lowerable;
46 import org.graalvm.compiler.nodes.spi.LoweringTool;
47 import org.graalvm.compiler.options.OptionValues;
48 import org.graalvm.compiler.phases.util.Providers;
49 import org.graalvm.compiler.replacements.SnippetTemplate.AbstractTemplates;
50 import org.graalvm.compiler.replacements.SnippetTemplate.Arguments;
51 import org.graalvm.compiler.replacements.SnippetTemplate.SnippetInfo;
52 import org.graalvm.compiler.word.ObjectAccess;
53 import org.graalvm.word.LocationIdentity;
54
55 import jdk.vm.ci.code.TargetDescription;
56 import sun.misc.Unsafe;
57
58 /**
59 * This node can be used to add a counter to the code that will estimate the dynamic number of calls
60 * by adding an increment to the compiled code. This should of course only be used for
61 * debugging/testing purposes.
62 *
63 * A unique counter will be created for each unique name passed to the constructor. Depending on the
64 * value of withContext, the name of the root method is added to the counter's name.
65 */
66 @NodeInfo(cycles = CYCLES_IGNORED, size = SIZE_IGNORED)
67 public class SnippetCounterNode extends FixedWithNextNode implements Lowerable {
68
69 public static final NodeClass<SnippetCounterNode> TYPE = NodeClass.create(SnippetCounterNode.class);
70
71 @Input protected ValueNode increment;
72
73 protected final SnippetCounter counter;
74
75 public SnippetCounterNode(SnippetCounter counter, ValueNode increment) {
76 super(TYPE, StampFactory.forVoid());
77 this.counter = counter;
78 this.increment = increment;
79 }
80
81 public SnippetCounter getCounter() {
82 return counter;
83 }
84
85 public ValueNode getIncrement() {
86 return increment;
87 }
88
89 @NodeIntrinsic
90 public static native void add(@ConstantNodeParameter SnippetCounter counter, int increment);
91
92 public static void increment(@ConstantNodeParameter SnippetCounter counter) {
93 add(counter, 1);
94 }
95
96 @Override
97 public void lower(LoweringTool tool) {
98 if (graph().getGuardsStage().areFrameStatesAtDeopts()) {
99 SnippetCounterSnippets.Templates templates = tool.getReplacements().getSnippetTemplateCache(SnippetCounterSnippets.Templates.class);
100 templates.lower(this, tool);
101 }
102 }
103
104 /**
105 * Add {@link #SNIPPET_COUNTER_LOCATION} to {@code privateLocations} if it isn't already there.
106 *
107 * @param privateLocations
108 * @return a copy of privateLocations with any needed locations added
109 */
110 public static LocationIdentity[] addSnippetCounters(LocationIdentity[] privateLocations) {
111 for (LocationIdentity location : privateLocations) {
112 if (location.equals(SNIPPET_COUNTER_LOCATION)) {
113 return privateLocations;
114 }
115 }
116 LocationIdentity[] result = Arrays.copyOf(privateLocations, privateLocations.length + 1);
117 result[result.length - 1] = SnippetCounterNode.SNIPPET_COUNTER_LOCATION;
118 return result;
119 }
120
121 /**
122 * We do not want to use the {@link LocationIdentity} of the {@link SnippetCounter#value()}
123 * field, so that the usage in snippets is always possible. If a method accesses the counter via
124 * the field and the snippet, the result might not be correct though.
125 */
126 public static final LocationIdentity SNIPPET_COUNTER_LOCATION = NamedLocationIdentity.mutable("SnippetCounter");
127
128 static class SnippetCounterSnippets implements Snippets {
129
130 @Fold
131 static int countOffset() {
132 try {
133 return (int) UNSAFE.objectFieldOffset(SnippetCounter.class.getDeclaredField("value"));
134 } catch (Exception e) {
135 throw new GraalError(e);
136 }
137 }
138
139 @Snippet
140 public static void add(@ConstantParameter SnippetCounter counter, int increment) {
141 long loadedValue = ObjectAccess.readLong(counter, countOffset(), SNIPPET_COUNTER_LOCATION);
142 ObjectAccess.writeLong(counter, countOffset(), loadedValue + increment, SNIPPET_COUNTER_LOCATION);
143 }
144
145 public static class Templates extends AbstractTemplates {
146
147 private final SnippetInfo add = snippet(SnippetCounterSnippets.class, "add", SNIPPET_COUNTER_LOCATION);
148
149 Templates(OptionValues options, Iterable<DebugHandlersFactory> factories, Providers providers, SnippetReflectionProvider snippetReflection, TargetDescription target) {
150 super(options, factories, providers, snippetReflection, target);
151 }
152
153 public void lower(SnippetCounterNode counter, LoweringTool tool) {
154 StructuredGraph graph = counter.graph();
155 Arguments args = new Arguments(add, graph.getGuardsStage(), tool.getLoweringStage());
156 args.addConst("counter", counter.getCounter());
157 args.add("increment", counter.getIncrement());
158
159 template(counter.getDebug(), args).instantiate(providers.getMetaAccess(), counter, DEFAULT_REPLACER, args);
160 }
161 }
162 }
163
164 private static final Unsafe UNSAFE = initUnsafe();
165
166 private static Unsafe initUnsafe() {
167 try {
168 return Unsafe.getUnsafe();
169 } catch (SecurityException se) {
170 try {
171 Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
172 theUnsafe.setAccessible(true);
173 return (Unsafe) theUnsafe.get(Unsafe.class);
174 } catch (Exception e) {
175 throw new RuntimeException("exception while trying to get Unsafe", e);
176 }
177 }
178 }
179 }