Bug 537399 - prevent GC on logical type results
Added a bit flag to instruct IAstEvaluationEngine to disable GC on the
result object.
Logical structures use this flag and only reenable GC when the program
resumes.
Change-Id: I0992957be34bad1992f49929c863a252435c4695
Signed-off-by: Julian Honnen <julian.honnen@vector.com>
diff --git a/org.eclipse.jdt.debug.tests/java9/LogicalStructures.java b/org.eclipse.jdt.debug.tests/java9/LogicalStructures.java
index cb268b3..1244ca8 100644
--- a/org.eclipse.jdt.debug.tests/java9/LogicalStructures.java
+++ b/org.eclipse.jdt.debug.tests/java9/LogicalStructures.java
@@ -12,11 +12,7 @@
* IBM Corporation - initial API and implementation
*******************************************************************************/
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
import java.util.Map.Entry;
/**
@@ -25,15 +21,30 @@
public class LogicalStructures {
public static void main(String[] args) {
- Map map = new HashMap();
- map.put("one", new Integer(1));
- map.put("two", new Integer(2));
- List list = new ArrayList();
+ generateGarbage();
+
+ Map<String, Integer> map = new HashMap<>();
+ map.put("one", 1);
+ map.put("two", 2);
+ List<String> list = new ArrayList<>();
list.add("three");
list.add("four");
- Set set = map.entrySet();
- Entry entry = (Entry) set.iterator().next();
+ Set<Entry<String, Integer>> set = map.entrySet();
+ 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"));
+ }
+ }, 50, 20);
+ }
}
diff --git a/org.eclipse.jdt.debug.tests/testprograms/LogicalStructures.java b/org.eclipse.jdt.debug.tests/testprograms/LogicalStructures.java
index cb268b3..1244ca8 100644
--- a/org.eclipse.jdt.debug.tests/testprograms/LogicalStructures.java
+++ b/org.eclipse.jdt.debug.tests/testprograms/LogicalStructures.java
@@ -12,11 +12,7 @@
* IBM Corporation - initial API and implementation
*******************************************************************************/
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
import java.util.Map.Entry;
/**
@@ -25,15 +21,30 @@
public class LogicalStructures {
public static void main(String[] args) {
- Map map = new HashMap();
- map.put("one", new Integer(1));
- map.put("two", new Integer(2));
- List list = new ArrayList();
+ generateGarbage();
+
+ Map<String, Integer> map = new HashMap<>();
+ map.put("one", 1);
+ map.put("two", 2);
+ List<String> list = new ArrayList<>();
list.add("three");
list.add("four");
- Set set = map.entrySet();
- Entry entry = (Entry) set.iterator().next();
+ Set<Entry<String, Integer>> set = map.entrySet();
+ 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"));
+ }
+ }, 50, 20);
+ }
}
diff --git a/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/variables/TestLogicalStructures.java b/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/variables/TestLogicalStructures.java
index d282a98..1d0f49b 100644
--- a/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/variables/TestLogicalStructures.java
+++ b/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/variables/TestLogicalStructures.java
@@ -46,7 +46,7 @@
*/
public void testListLogicalStructure() throws Exception {
String typeName = "LogicalStructures";
- createLineBreakpoint(36, typeName);
+ createLineBreakpoint(34, typeName);
IJavaThread thread= null;
try {
thread= launchToBreakpoint(typeName);
@@ -66,6 +66,7 @@
assertEquals("Should be one logical structure type", 1, types.length);
IJavaObject logicalValue = (IJavaObject) types[0].getLogicalStructure(value);
+ Thread.sleep(200); // run a few GC cycles
assertEquals("Logical value should be an array", "java.lang.Object[]", logicalValue.getJavaType().getName());
IJavaArray array = (IJavaArray) logicalValue;
@@ -84,7 +85,7 @@
*/
public void testMapLogicalStructure() throws Exception {
String typeName = "LogicalStructures";
- createLineBreakpoint(33, typeName);
+ createLineBreakpoint(34, typeName);
IJavaThread thread= null;
try {
thread= launchToBreakpoint(typeName);
@@ -104,6 +105,7 @@
assertEquals("Should be one logical structure type", 1, types.length);
IJavaObject logicalValue = (IJavaObject) types[0].getLogicalStructure(value);
+ Thread.sleep(200); // run a few GC cycles
assertEquals("Logical value should be an array", "java.lang.Object[]", logicalValue.getJavaType().getName());
IJavaArray array = (IJavaArray) logicalValue;
@@ -122,7 +124,7 @@
*/
public void testEntryLogicalStructure() throws Exception {
String typeName = "LogicalStructures";
- createLineBreakpoint(36, typeName);
+ createLineBreakpoint(34, typeName);
IJavaThread thread= null;
try {
thread= launchToBreakpoint(typeName);
@@ -142,6 +144,7 @@
assertEquals("Should be one logical structure type", 1, types.length);
IJavaObject logicalValue = (IJavaObject) types[0].getLogicalStructure(value);
+ Thread.sleep(200); // run a few GC cycles
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());
diff --git a/org.eclipse.jdt.debug/eval/org/eclipse/jdt/debug/eval/IAstEvaluationEngine.java b/org.eclipse.jdt.debug/eval/org/eclipse/jdt/debug/eval/IAstEvaluationEngine.java
index c1156bb..394f322 100644
--- a/org.eclipse.jdt.debug/eval/org/eclipse/jdt/debug/eval/IAstEvaluationEngine.java
+++ b/org.eclipse.jdt.debug/eval/org/eclipse/jdt/debug/eval/IAstEvaluationEngine.java
@@ -33,6 +33,14 @@
public interface IAstEvaluationEngine extends IEvaluationEngine {
/**
+ * Instructs the evaluation engine to disable garbage collection on the result object. The caller is then responsible to call
+ * {@link IJavaObject#enableCollection()} on the evaluated result. Can be passed as a bit flag to the <code>evaluationDetail</code> parameter.
+ *
+ * @since 3.17
+ */
+ int DISABLE_GC_ON_RESULT = 0x0100;
+
+ /**
* Asynchronously evaluates the given expression in the context of the
* specified stack frame, reporting the result back to the given listener.
* The thread is resumed from the location at which it is currently
@@ -50,8 +58,9 @@
* the listener that will receive notification when/if the
* evaluation completes
* @param evaluationDetail
- * one of <code>DebugEvent.EVALUATION</code> or
- * <code>DebugEvent.EVALUATION_IMPLICIT</code>
+ * bitmask of one of <code>DebugEvent.EVALUATION</code> or
+ * <code>DebugEvent.EVALUATION_IMPLICIT</code> and
+ * optionally <code>DISABLE_GC_ON_RESULT</code>
* @param hitBreakpoints
* whether or not breakpoints should be honored in the evaluation
* thread during the evaluation. If <code>false</code>,
@@ -97,8 +106,9 @@
* the listener that will receive notification when/if the
* evaluation completes
* @param evaluationDetail
- * one of <code>DebugEvent.EVALUATION</code> or
- * <code>DebugEvent.EVALUATION_IMPLICIT</code>
+ * bitmask of one of <code>DebugEvent.EVALUATION</code> or
+ * <code>DebugEvent.EVALUATION_IMPLICIT</code> and
+ * optionally <code>DISABLE_GC_ON_RESULT</code>
* @param hitBreakpoints
* whether or not breakpoints should be honored in the evaluation
* thread during the evaluation. If <code>false</code>,
diff --git a/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/ASTEvaluationEngine.java b/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/ASTEvaluationEngine.java
index edb4f8a..b5be5c5 100644
--- a/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/ASTEvaluationEngine.java
+++ b/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/ASTEvaluationEngine.java
@@ -79,6 +79,7 @@
public class ASTEvaluationEngine implements IAstEvaluationEngine {
public static final String ANONYMOUS_VAR_PREFIX = "val$"; //$NON-NLS-1$
+ private static final int EVALUATION_DETAIL_BITMASK = DebugEvent.EVALUATION | DebugEvent.EVALUATION_IMPLICIT;
private IJavaProject fProject;
private IJavaDebugTarget fDebugTarget;
@@ -699,6 +700,8 @@
private IEvaluationListener fListener;
+ private boolean fDisableGcOnResult;
+
public EvalRunnable(InstructionSequence expression, IJavaThread thread,
IRuntimeContext context, IEvaluationListener listener,
int evaluationDetail, boolean hitBreakpoints) {
@@ -706,8 +709,9 @@
fThread = thread;
fContext = context;
fListener = listener;
- fEvaluationDetail = evaluationDetail;
+ fEvaluationDetail = (evaluationDetail & EVALUATION_DETAIL_BITMASK);
fHitBreakpoints = hitBreakpoints;
+ fDisableGcOnResult = (evaluationDetail & IAstEvaluationEngine.DISABLE_GC_ON_RESULT) != 0;
}
@Override
@@ -774,7 +778,7 @@
EventFilter filter = new EventFilter();
try {
DebugPlugin.getDefault().addDebugEventFilter(filter);
- interpreter.execute();
+ interpreter.execute(fDisableGcOnResult);
} catch (CoreException exception) {
fException = exception;
if (fEvaluationDetail == DebugEvent.EVALUATION
diff --git a/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/Interpreter.java b/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/Interpreter.java
index 51377b8..9a3a2b5 100644
--- a/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/Interpreter.java
+++ b/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/Interpreter.java
@@ -60,7 +60,7 @@
fInternalVariables = new HashMap<>();
}
- public void execute() throws CoreException {
+ public void execute(boolean disableGcOnResult) throws CoreException {
try {
reset();
while (fInstructionCounter < fInstructions.length && !fStopped) {
@@ -75,7 +75,7 @@
throw new CoreException(new Status(IStatus.ERROR,
JDIDebugModel.getPluginIdentifier(), e.getMessage(), e));
} finally {
- releaseObjects();
+ releaseObjects(disableGcOnResult);
}
}
@@ -132,13 +132,16 @@
/**
* Re-enable garbage collection if interim results.
*/
- private void releaseObjects() {
+ private void releaseObjects(boolean disableGcOnResult) {
if (fPermStorage != null) {
+ IJavaValue result = getResult();
Iterator<IJavaObject> iterator = fPermStorage.iterator();
while (iterator.hasNext()) {
IJavaObject object = iterator.next();
try {
- object.enableCollection();
+ if (!disableGcOnResult || object != result) {
+ object.enableCollection();
+ }
} catch (CoreException e) {
// don't worry about GC if the VM has terminated
if ((e.getStatus().getException() instanceof VMDisconnectedException)) {
diff --git a/org.eclipse.jdt.debug/model/org/eclipse/jdt/internal/debug/core/logicalstructures/JavaLogicalStructure.java b/org.eclipse.jdt.debug/model/org/eclipse/jdt/internal/debug/core/logicalstructures/JavaLogicalStructure.java
index 2c180f5..e54c8c8 100644
--- a/org.eclipse.jdt.debug/model/org/eclipse/jdt/internal/debug/core/logicalstructures/JavaLogicalStructure.java
+++ b/org.eclipse.jdt.debug/model/org/eclipse/jdt/internal/debug/core/logicalstructures/JavaLogicalStructure.java
@@ -30,6 +30,7 @@
import org.eclipse.debug.core.ILogicalStructureType;
import org.eclipse.debug.core.IStatusHandler;
import org.eclipse.debug.core.model.IDebugTarget;
+import org.eclipse.debug.core.model.ILogicalStructureTypeDelegate3;
import org.eclipse.debug.core.model.IThread;
import org.eclipse.debug.core.model.IValue;
import org.eclipse.jdt.core.IJavaProject;
@@ -43,7 +44,6 @@
import org.eclipse.jdt.debug.core.IJavaThread;
import org.eclipse.jdt.debug.core.IJavaType;
import org.eclipse.jdt.debug.core.IJavaValue;
-import org.eclipse.jdt.debug.core.IJavaVariable;
import org.eclipse.jdt.debug.eval.IAstEvaluationEngine;
import org.eclipse.jdt.debug.eval.ICompiledExpression;
import org.eclipse.jdt.debug.eval.IEvaluationListener;
@@ -55,7 +55,7 @@
-public class JavaLogicalStructure implements ILogicalStructureType {
+public class JavaLogicalStructure implements ILogicalStructureType, ILogicalStructureTypeDelegate3 {
private static IStatusHandler fgStackFrameProvider;
@@ -151,7 +151,7 @@
fResult = null;
fEvaluationEngine.evaluateExpression(compiledExpression,
fEvaluationValue, fThread, this,
- DebugEvent.EVALUATION_IMPLICIT, false);
+ DebugEvent.EVALUATION_IMPLICIT | IAstEvaluationEngine.DISABLE_GC_ON_RESULT, false);
synchronized (this) {
if (fResult == null) {
try {
@@ -310,7 +310,7 @@
evaluationEngine);
if (fValue == null) {
// evaluate each variable
- IJavaVariable[] variables = new IJavaVariable[fVariables.length];
+ JDIPlaceholderVariable[] variables = new JDIPlaceholderVariable[fVariables.length];
for (int i = 0; i < fVariables.length; i++) {
variables[i] = new JDIPlaceholderVariable(fVariables[i][0],
evaluationBlock.evaluate(fVariables[i][1]),
@@ -334,6 +334,17 @@
return value;
}
+ @Override
+ public void releaseValue(IValue value) {
+ if (value instanceof IJavaObject) {
+ try {
+ ((IJavaObject) value).enableCollection();
+ } catch (DebugException e) {
+ JDIDebugPlugin.log(e);
+ }
+ }
+ }
+
/**
* Returns the <code>IJavaReferenceType</code> from the specified
* <code>IJavaObject</code>
diff --git a/org.eclipse.jdt.debug/model/org/eclipse/jdt/internal/debug/core/logicalstructures/LogicalObjectStructureValue.java b/org.eclipse.jdt.debug/model/org/eclipse/jdt/internal/debug/core/logicalstructures/LogicalObjectStructureValue.java
index 8eea396..b2c2d8f 100644
--- a/org.eclipse.jdt.debug/model/org/eclipse/jdt/internal/debug/core/logicalstructures/LogicalObjectStructureValue.java
+++ b/org.eclipse.jdt.debug/model/org/eclipse/jdt/internal/debug/core/logicalstructures/LogicalObjectStructureValue.java
@@ -16,13 +16,13 @@
import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.core.ILaunch;
import org.eclipse.debug.core.model.IDebugTarget;
+import org.eclipse.debug.core.model.IValue;
import org.eclipse.debug.core.model.IVariable;
import org.eclipse.jdt.debug.core.IJavaFieldVariable;
import org.eclipse.jdt.debug.core.IJavaObject;
import org.eclipse.jdt.debug.core.IJavaThread;
import org.eclipse.jdt.debug.core.IJavaType;
import org.eclipse.jdt.debug.core.IJavaValue;
-import org.eclipse.jdt.debug.core.IJavaVariable;
/**
* A proxy to an object representing the logical structure of that object.
@@ -30,7 +30,7 @@
public class LogicalObjectStructureValue implements IJavaObject {
private IJavaObject fObject;
- private IJavaVariable[] fVariables;
+ private JDIPlaceholderVariable[] fVariables;
/**
* Constructs a proxy to the given object, with the given variables as
@@ -42,7 +42,7 @@
* java variables to add as children to this object
*/
public LogicalObjectStructureValue(IJavaObject object,
- IJavaVariable[] variables) {
+ JDIPlaceholderVariable[] variables) {
fObject = object;
fVariables = variables;
}
@@ -269,6 +269,13 @@
@Override
public void enableCollection() throws DebugException {
fObject.enableCollection();
+
+ for (JDIPlaceholderVariable variable : fVariables) {
+ IValue variableValue = variable.getValue();
+ if (variableValue instanceof IJavaObject) {
+ ((IJavaObject) variableValue).enableCollection();
+ }
+ }
}
/*
