src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.test/src/org/graalvm/compiler/core/test/LockEliminationTest.java
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package org.graalvm.compiler.core.test;
import org.graalvm.compiler.loop.DefaultLoopPolicies;
import org.graalvm.compiler.loop.phases.LoopFullUnrollPhase;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
import org.graalvm.compiler.nodes.java.MonitorExitNode;
import org.graalvm.compiler.nodes.java.RawMonitorEnterNode;
import org.graalvm.compiler.nodes.spi.LoweringTool;
import org.graalvm.compiler.phases.common.CanonicalizerPhase;
import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;
import org.graalvm.compiler.phases.common.LockEliminationPhase;
import org.graalvm.compiler.phases.common.LoweringPhase;
import org.graalvm.compiler.phases.tiers.HighTierContext;
import org.graalvm.compiler.virtual.phases.ea.PartialEscapePhase;
import org.junit.Test;
import jdk.vm.ci.meta.ResolvedJavaMethod;
public class LockEliminationTest extends GraalCompilerTest {
static class A {
int value;
public synchronized int getValue() {
return value;
}
}
static int field1;
static int field2;
public static void testSynchronizedSnippet(A x, A y) {
synchronized (x) {
field1 = x.value;
}
synchronized (x) {
field2 = y.value;
}
}
@Test
public void testLock() {
test("testSynchronizedSnippet", new A(), new A());
StructuredGraph graph = getGraph("testSynchronizedSnippet", false);
new CanonicalizerPhase().apply(graph, getProviders());
new LockEliminationPhase().apply(graph);
assertDeepEquals(1, graph.getNodes().filter(RawMonitorEnterNode.class).count());
assertDeepEquals(1, graph.getNodes().filter(MonitorExitNode.class).count());
}
public static void testSynchronizedMethodSnippet(A x) {
int value1 = x.getValue();
int value2 = x.getValue();
field1 = value1;
field2 = value2;
}
@Test
public void testSynchronizedMethod() {
test("testSynchronizedMethodSnippet", new A());
StructuredGraph graph = getGraph("testSynchronizedMethodSnippet", false);
new CanonicalizerPhase().apply(graph, getProviders());
new LockEliminationPhase().apply(graph);
assertDeepEquals(1, graph.getNodes().filter(RawMonitorEnterNode.class).count());
assertDeepEquals(1, graph.getNodes().filter(MonitorExitNode.class).count());
}
public void testUnrolledSyncSnippet(Object a) {
for (int i = 0; i < 3; i++) {
synchronized (a) {
}
}
}
@Test
public void testUnrolledSync() {
StructuredGraph graph = getGraph("testUnrolledSyncSnippet", false);
CanonicalizerPhase canonicalizer = new CanonicalizerPhase();
canonicalizer.apply(graph, getProviders());
HighTierContext context = getDefaultHighTierContext();
new LoopFullUnrollPhase(canonicalizer, new DefaultLoopPolicies()).apply(graph, context);
new LockEliminationPhase().apply(graph);
assertDeepEquals(1, graph.getNodes().filter(RawMonitorEnterNode.class).count());
assertDeepEquals(1, graph.getNodes().filter(MonitorExitNode.class).count());
}
private StructuredGraph getGraph(String snippet, boolean doEscapeAnalysis) {
ResolvedJavaMethod method = getResolvedJavaMethod(snippet);
StructuredGraph graph = parseEager(method, AllowAssumptions.YES);
HighTierContext context = getDefaultHighTierContext();
CanonicalizerPhase canonicalizer = new CanonicalizerPhase();
canonicalizer.apply(graph, context);
createInliningPhase().apply(graph, context);
new CanonicalizerPhase().apply(graph, context);
new DeadCodeEliminationPhase().apply(graph);
if (doEscapeAnalysis) {
new PartialEscapePhase(true, canonicalizer, graph.getOptions()).apply(graph, context);
}
new LoweringPhase(new CanonicalizerPhase(), LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, context);
return graph;
}
public void testEscapeAnalysisSnippet(A a) {
A newA = new A();
synchronized (newA) {
synchronized (a) {
field1 = a.value;
}
}
/*
* Escape analysis removes the synchronization on newA. But lock elimination still must not
* combine the two synchronizations on the parameter a because they have a different lock
* depth.
*/
synchronized (a) {
field2 = a.value;
}
/*
* Lock elimination can combine these synchronizations, since they are both on parameter a
* with the same lock depth.
*/
synchronized (a) {
field1 = a.value;
}
}
@Test
public void testEscapeAnalysis() {
StructuredGraph graph = getGraph("testEscapeAnalysisSnippet", true);
assertDeepEquals(3, graph.getNodes().filter(RawMonitorEnterNode.class).count());
assertDeepEquals(3, graph.getNodes().filter(MonitorExitNode.class).count());
new LockEliminationPhase().apply(graph);
assertDeepEquals(2, graph.getNodes().filter(RawMonitorEnterNode.class).count());
assertDeepEquals(2, graph.getNodes().filter(MonitorExitNode.class).count());
}
}