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Merged
iloveeclipse merged 1 commit into from
Feb 26, 2026
+87 −37
Merged

Trigger GC in test snippet via JDI #878

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25 changes: 10 additions & 15 deletions org.eclipse.jdt.debug.tests/java9/LogicalStructures.java
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Original file line number Diff line number Diff line change
Expand Up @@ -19,10 +19,8 @@
* Tests built in logical structures.
*/
public class LogicalStructures {

public static void main(String[] args) {
generateGarbage();

Map<String, Integer> map = new HashMap<>();
map.put("one", 1);
map.put("two", 2);
Expand All @@ -33,18 +31,15 @@ public static void main(String[] args) {
Map.Entry<String, Integer> entry = set.iterator().next();
entry.getKey();
}

private static void generateGarbage() {
// generate garbage repeatedly to verify that logical values don't get GCed
Timer timer = new Timer(true);
timer.scheduleAtFixedRate(new TimerTask() {
private List<String> garbage;
@Override
public void run() {
System.gc();
garbage = Arrays.asList(new String("a"), new String("b"), new String("c"));
}
}, 200, 20);

// called from test to verify that logical values don't get GCed
private static void generateGarbageAndGC() throws InterruptedException {
List<Object> garbage;
for (int i = 0; i < 10; ++i) {
System.gc();
garbage = Arrays.asList(new Object(), new Object(), new Object());
Thread.sleep(20);
}
}

}
25 changes: 10 additions & 15 deletions org.eclipse.jdt.debug.tests/testprograms/LogicalStructures.java
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Original file line number Diff line number Diff line change
Expand Up @@ -19,10 +19,8 @@
* Tests built in logical structures.
*/
public class LogicalStructures {

public static void main(String[] args) {
generateGarbage();

Map<String, Integer> map = new HashMap<>();
map.put("one", 1);
map.put("two", 2);
Expand All @@ -33,18 +31,15 @@ public static void main(String[] args) {
Map.Entry<String, Integer> entry = set.iterator().next();
entry.getKey();
}

private static void generateGarbage() {
// generate garbage repeatedly to verify that logical values don't get GCed
Timer timer = new Timer(true);
timer.scheduleAtFixedRate(new TimerTask() {
private List<String> garbage;
@Override
public void run() {
System.gc();
garbage = Arrays.asList(new String("a"), new String("b"), new String("c"));
}
}, 200, 20);

// called from test to verify that logical values don't get GCed
private static void generateGarbageAndGC() throws InterruptedException {
List<Object> garbage;
for (int i = 0; i < 10; ++i) {
System.gc();
garbage = Arrays.asList(new Object(), new Object(), new Object());
Thread.sleep(20);
}
}

}
74 changes: 67 additions & 7 deletions ...se.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/variables/TestLogicalStructures.java
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Original file line number Diff line number Diff line change
Expand Up @@ -13,17 +13,29 @@
*******************************************************************************/
package org.eclipse.jdt.debug.tests.variables;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.concurrent.atomic.AtomicBoolean;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.debug.core.DebugEvent;
import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILogicalStructureType;
import org.eclipse.debug.core.model.IBreakpoint;
import org.eclipse.debug.core.model.IValue;
import org.eclipse.debug.core.model.IVariable;
import org.eclipse.jdt.debug.core.IJavaArray;
import org.eclipse.jdt.debug.core.IJavaDebugTarget;
import org.eclipse.jdt.debug.core.IJavaObject;
import org.eclipse.jdt.debug.core.IJavaStackFrame;
import org.eclipse.jdt.debug.core.IJavaThread;
import org.eclipse.jdt.debug.core.IJavaVariable;
import org.eclipse.jdt.debug.eval.IAstEvaluationEngine;
import org.eclipse.jdt.debug.eval.IEvaluationListener;
import org.eclipse.jdt.debug.eval.IEvaluationResult;
import org.eclipse.jdt.debug.tests.AbstractDebugTest;
import org.eclipse.jdt.internal.debug.core.JDIDebugPlugin;

/**
* Tests for logical structures
Expand All @@ -44,7 +56,7 @@ public TestLogicalStructures(String name) {
*/
public void testListLogicalStructure() throws Exception {
String typeName = "LogicalStructures";
createLineBreakpoint(34, typeName);
createLineBreakpoint(32, typeName);
IJavaThread thread= null;
try {
thread= launchToBreakpoint(typeName);
Expand All @@ -64,7 +76,7 @@ public void testListLogicalStructure() throws Exception {
assertEquals("Should be one logical structure type", 1, types.length);

IJavaObject logicalValue = (IJavaObject) types[0].getLogicalStructure(value);
Thread.sleep(500); // run a few GC cycles
gcInSnippet(frame);
assertEquals("Logical value should be an array", "java.lang.Object[]", logicalValue.getJavaType().getName());

IJavaArray array = (IJavaArray) logicalValue;
Expand All @@ -81,7 +93,7 @@ public void testListLogicalStructure() throws Exception {
*/
public void testMapLogicalStructure() throws Exception {
String typeName = "LogicalStructures";
createLineBreakpoint(34, typeName);
createLineBreakpoint(32, typeName);
IJavaThread thread= null;
try {
thread= launchToBreakpoint(typeName);
Expand All @@ -101,7 +113,7 @@ public void testMapLogicalStructure() throws Exception {
assertEquals("Should be one logical structure type", 1, types.length);

IJavaObject logicalValue = (IJavaObject) types[0].getLogicalStructure(value);
Thread.sleep(500); // run a few GC cycles
gcInSnippet(frame);
assertEquals("Logical value should be an array", "java.lang.Object[]", logicalValue.getJavaType().getName());

IJavaArray array = (IJavaArray) logicalValue;
Expand All @@ -118,7 +130,7 @@ public void testMapLogicalStructure() throws Exception {
*/
public void testEntryLogicalStructure() throws Exception {
String typeName = "LogicalStructures";
createLineBreakpoint(34, typeName);
createLineBreakpoint(32, typeName);
IJavaThread thread= null;
try {
thread= launchToBreakpoint(typeName);
Expand All @@ -138,15 +150,63 @@ public void testEntryLogicalStructure() throws Exception {
assertEquals("Should be one logical structure type", 1, types.length);

IJavaObject logicalValue = (IJavaObject) types[0].getLogicalStructure(value);
Thread.sleep(500); // run a few GC cycles
gcInSnippet(frame);
IVariable[] children = logicalValue.getVariables();
assertEquals("Should be two elements in the structure", 2, children.length);
assertEquals("First entry should be key", "key", children[0].getName());
assertEquals("Second entry should be value", "value", children[1].getName());

} finally {
terminateAndRemove(thread);
removeAllBreakpoints();
}
}

private void gcInSnippet(IJavaStackFrame stackFrame) throws CoreException, InterruptedException {
IAstEvaluationEngine engine = JDIDebugPlugin.getDefault().getEvaluationEngine(getProjectContext(), (IJavaDebugTarget) stackFrame.getDebugTarget());
EvaluationListener listener = new EvaluationListener();
engine.evaluate("generateGarbageAndGC()", stackFrame, listener, DebugEvent.EVALUATION_IMPLICIT, false);
listener.await();

}

private static class EvaluationListener implements IEvaluationListener {

private final AtomicBoolean done = new AtomicBoolean(false);
private final StringBuilder errors = new StringBuilder();

@Override
public void evaluationComplete(IEvaluationResult result) {
if (result.hasErrors()) {
errors.append("Evaluation resulted in errors:");
errors.append(System.lineSeparator());
for (String error : result.getErrorMessages()) {
errors.append(error);
errors.append(System.lineSeparator());
}
DebugException exception = result.getException();
if (exception != null) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
exception.printStackTrace(pw);
errors.append(sw.getBuffer().toString());
errors.append(System.lineSeparator());
}
}
done.set(true);

}

private void await() throws InterruptedException {
long start = System.currentTimeMillis();
while (!done.get() && System.currentTimeMillis() - start <= DEFAULT_TIMEOUT) {
Thread.sleep(10);
}
if (!done.get()) {
fail("Timeout occurred while waiting on evaluation result");
}
if (!errors.isEmpty()) {
fail(errors.toString());
}
}
}
}
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