Bug 229621 ClassLoader Deadlock Occuring with IBM JDK.
diff --git a/bundles/org.eclipse.osgi/defaultAdaptor/src/org/eclipse/osgi/baseadaptor/loader/ClasspathManager.java b/bundles/org.eclipse.osgi/defaultAdaptor/src/org/eclipse/osgi/baseadaptor/loader/ClasspathManager.java
index 89976c2..33c821c 100644
--- a/bundles/org.eclipse.osgi/defaultAdaptor/src/org/eclipse/osgi/baseadaptor/loader/ClasspathManager.java
+++ b/bundles/org.eclipse.osgi/defaultAdaptor/src/org/eclipse/osgi/baseadaptor/loader/ClasspathManager.java
@@ -1,5 +1,5 @@
/*******************************************************************************
- * Copyright (c) 2005, 2007 IBM Corporation and others.
+ * Copyright (c) 2005, 2008 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
@@ -23,6 +23,7 @@
import org.eclipse.osgi.baseadaptor.hooks.ClassLoadingStatsHook;
import org.eclipse.osgi.framework.adaptor.BundleData;
import org.eclipse.osgi.framework.debug.Debug;
+import org.eclipse.osgi.framework.internal.core.FrameworkProperties;
import org.eclipse.osgi.internal.baseadaptor.AdaptorMsg;
import org.eclipse.osgi.util.NLS;
import org.osgi.framework.BundleException;
@@ -31,7 +32,7 @@
/**
* A helper class for <code>BaseClassLoader</code> implementations. This class will keep track of
* <code>ClasspathEntry</code> objects for the host bundle and any attached fragment bundles. This
- * class takes care of seaching the <code>ClasspathEntry</code> objects for a base class loader
+ * class takes care of searching the <code>ClasspathEntry</code> objects for a base class loader
* implementation. Additional behavior may be added to a classpath manager by configuring
* <code>ClassLoadingHook</code> and <code>ClassLoadingStatsHook</code>.
* @see BaseClassLoader
@@ -41,14 +42,18 @@
*/
public class ClasspathManager {
private static final FragmentClasspath[] emptyFragments = new FragmentClasspath[0];
+ private final static String PROP_CLASSLOADER_LOCK = "osgi.classloader.lock"; //$NON-NLS-1$
+ private final static String VALUE_CLASSNAME_LOCK = "classname"; //$NON-NLS-1$
+ private final static boolean LOCK_CLASSNAME = VALUE_CLASSNAME_LOCK.equals(FrameworkProperties.getProperty(PROP_CLASSLOADER_LOCK));
private BaseData data;
private String[] classpath;
private ClasspathEntry[] entries;
private BaseClassLoader classloader;
private FragmentClasspath[] fragments = emptyFragments;
- // a colloction of String[2], each element is {"libname", "libpath"}
+ // a collection of String[2], each element is {"libname", "libpath"}
private Collection loadedLibraries = null;
+ private HashMap classNameLocks = new HashMap(5);
/**
* Constructs a classpath manager for the given host base data, classpath and base class loader
@@ -412,7 +417,10 @@
try {
for (int i = 0; i < hooks.length; i++)
hooks[i].preFindLocalClass(classname, this);
- result = findLocalClassImpl(classname, hooks);
+ if (LOCK_CLASSNAME)
+ result = findLocalClass_LockClassName(classname, hooks);
+ else
+ result = findLocalClass_LockClassLoader(classname, hooks);
return result;
} finally {
for (int i = 0; i < hooks.length; i++)
@@ -420,33 +428,76 @@
}
}
+ private Class findLocalClass_LockClassName(String classname, ClassLoadingStatsHook[] hooks) throws ClassNotFoundException {
+ boolean initialLock = lockClassName(classname);
+ try {
+ return findLocalClassImpl(classname, hooks);
+ } finally {
+ if (initialLock)
+ unlockClassName(classname);
+ }
+ }
+
+ private Class findLocalClass_LockClassLoader(String classname, ClassLoadingStatsHook[] hooks) throws ClassNotFoundException {
+ synchronized (classloader) {
+ return findLocalClassImpl(classname, hooks);
+ }
+ }
+
private Class findLocalClassImpl(String classname, ClassLoadingStatsHook[] hooks) throws ClassNotFoundException {
// must call findLoadedClass here even if it was called earlier,
// the findLoadedClass and defineClass calls must be atomic
- synchronized (classloader) {
- Class result = classloader.publicFindLoaded(classname);
- if (result != null)
- return result;
- for (int i = 0; i < entries.length; i++) {
- if (entries[i] != null) {
- result = findClassImpl(classname, entries[i], hooks);
- if (result != null)
- return result;
- }
+ Class result = classloader.publicFindLoaded(classname);
+ if (result != null)
+ return result;
+ for (int i = 0; i < entries.length; i++) {
+ if (entries[i] != null) {
+ result = findClassImpl(classname, entries[i], hooks);
+ if (result != null)
+ return result;
}
- // look in fragments.
- for (int i = 0; i < fragments.length; i++) {
- ClasspathEntry[] fragEntries = fragments[i].getEntries();
- for (int j = 0; j < fragEntries.length; j++) {
- result = findClassImpl(classname, fragEntries[j], hooks);
- if (result != null)
- return result;
- }
+ }
+ // look in fragments.
+ for (int i = 0; i < fragments.length; i++) {
+ ClasspathEntry[] fragEntries = fragments[i].getEntries();
+ for (int j = 0; j < fragEntries.length; j++) {
+ result = findClassImpl(classname, fragEntries[j], hooks);
+ if (result != null)
+ return result;
}
}
throw new ClassNotFoundException(classname);
}
+ private boolean lockClassName(String classname) throws ClassNotFoundException {
+ synchronized (classNameLocks) {
+ Object lockingThread = classNameLocks.get(classname);
+ Thread current = Thread.currentThread();
+ if (lockingThread == current)
+ return false;
+ while (true) {
+ if (lockingThread == null) {
+ classNameLocks.put(classname, current);
+ return true;
+ }
+ try {
+ classNameLocks.wait();
+ lockingThread = classNameLocks.get(classname);
+ } catch (InterruptedException e) {
+ current.interrupt();
+ throw new ClassNotFoundException(classname);
+ }
+ }
+ }
+ }
+
+ private void unlockClassName(String classname) {
+ synchronized (classNameLocks) {
+ classNameLocks.remove(classname);
+ classNameLocks.notifyAll();
+ }
+ }
+
private Class findClassImpl(String name, ClasspathEntry classpathEntry, ClassLoadingStatsHook[] hooks) {
if (Debug.DEBUG && Debug.DEBUG_LOADER)
Debug.println("BundleClassLoader[" + classpathEntry.getBundleFile() + "].findClass(" + name + ")"); //$NON-NLS-1$ //$NON-NLS-2$//$NON-NLS-3$
diff --git a/bundles/org.eclipse.osgi/eclipseAdaptor/src/org/eclipse/core/runtime/internal/adaptor/EclipseClassLoadingHook.java b/bundles/org.eclipse.osgi/eclipseAdaptor/src/org/eclipse/core/runtime/internal/adaptor/EclipseClassLoadingHook.java
index c2ce6ca..aad589f 100644
--- a/bundles/org.eclipse.osgi/eclipseAdaptor/src/org/eclipse/core/runtime/internal/adaptor/EclipseClassLoadingHook.java
+++ b/bundles/org.eclipse.osgi/eclipseAdaptor/src/org/eclipse/core/runtime/internal/adaptor/EclipseClassLoadingHook.java
@@ -30,6 +30,7 @@
private static String[] NL_JAR_VARIANTS = buildNLJarVariants(EclipseEnvironmentInfo.getDefault().getNL());
private static boolean DEFINE_PACKAGES;
private static String[] LIB_VARIANTS = buildLibraryVariants();
+ private Object pkgLock = new Object();
static {
try {
@@ -65,9 +66,12 @@
if (lastIndex < 0)
return null;
String packageName = name.substring(0, lastIndex);
- Object pkg = manager.getBaseClassLoader().publicGetPackage(packageName);
- if (pkg != null)
- return null;
+ Object pkg;
+ synchronized (pkgLock) {
+ pkg = manager.getBaseClassLoader().publicGetPackage(packageName);
+ if (pkg != null)
+ return null;
+ }
// get info about the package from the classpath entry's manifest.
String specTitle = null, specVersion = null, specVendor = null, implTitle = null, implVersion = null, implVendor = null;
@@ -107,7 +111,12 @@
}
// The package is not defined yet define it before we define the class.
// TODO still need to seal packages.
- manager.getBaseClassLoader().publicDefinePackage(packageName, specTitle, specVersion, specVendor, implTitle, implVersion, implVendor, null);
+ synchronized (pkgLock) {
+ pkg = manager.getBaseClassLoader().publicGetPackage(packageName);
+ if (pkg != null)
+ return null;
+ manager.getBaseClassLoader().publicDefinePackage(packageName, specTitle, specVersion, specVendor, implTitle, implVersion, implVendor, null);
+ }
// not doing any byte processing
return null;
}
