How to Fix Eclipse Debug Hang - eclipse

Question

I'm running Ubuntu 10.04 LTS and Eclipse Version: Helios Service Release 2
Build id: 20110218-091, debugging PHP. While it doesn't happen every time, after I'm done debugging when I click the red square to stop the process the Eclipse screen goes grey, and stays there. A top, or System Monitor shows Eclipse is using whatever CPU cycles remain, which in my case is between 67-85%. It'll stay this way until I kill the process (I've waited up to 10 or more minutes). The last error in the log is:
Plug-in net.sf.simpletest.eclipse was unable to load class net.sf.simpletest.eclipse.launcher.SimpletestLaunchShortcut.Plug-in net.sf.simpletest.eclipse was unable to load class net.sf.simpletest.eclipse.launcher.SimpletestLaunchShortcut.
This just started happening today so I'm inclined to think something's up with my machine, an update from Ubuntu, memory???
Output from Eclipse Event Details is below.
Any suggestions would be most welcome.
eclipse.buildId=M20110210-1200
java.version=1.6.0_20
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=linux, ARCH=x86, WS=gtk, NL=en_US
Framework arguments: -product org.eclipse.epp.package.java.product
Command-line arguments: -os linux -ws gtk -arch x86 -product org.eclipse.epp.package.java.product
Error
Tue Oct 11 14:35:03 EDT 2011
Plug-in net.sf.simpletest.eclipse was unable to load class net.sf.simpletest.eclipse.launcher.SimpletestLaunchShortcut.
org.eclipse.core.runtime.internal.adaptor.EclipseLazyStarter$TerminatingClassNotFoundException: An error occurred while automatically activating bundle net.sf.simpletest.eclipse (505).
at org.eclipse.core.runtime.internal.adaptor.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:121)
at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass(ClasspathManager.java:453)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.findLocalClass(DefaultClassLoader.java:216)
at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:393)
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:469)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:422)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:410)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
at org.eclipse.osgi.internal.loader.BundleLoader.loadClass(BundleLoader.java:338)
at org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java:232)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadClass(AbstractBundle.java:1197)
at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:174)
at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:904)
at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:55)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchShortcutExtension.getDelegate(LaunchShortcutExtension.java:410)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchShortcutExtension.getLaunchConfigurations(LaunchShortcutExtension.java:505)
at org.eclipse.debug.internal.ui.contextlaunching.LaunchingResourceManager.getParticipatingLaunchConfigurations(LaunchingResourceManager.java:486)
at org.eclipse.debug.internal.ui.contextlaunching.LaunchingResourceManager.getLabel(LaunchingResourceManager.java:320)
at org.eclipse.debug.internal.ui.contextlaunching.LaunchingResourceManager.computeLabels(LaunchingResourceManager.java:241)
at org.eclipse.debug.internal.ui.contextlaunching.LaunchingResourceManager$2.run(LaunchingResourceManager.java:138)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)
Caused by: org.osgi.framework.BundleException: The activator net.sf.simpletest.eclipse.SimpletestPlugin for bundle net.sf.simpletest.eclipse is invalid
at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadBundleActivator(AbstractBundle.java:156)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:751)
at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:370)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:284)
at org.eclipse.osgi.framework.util.SecureAction.start(SecureAction.java:417)
at org.eclipse.osgi.internal.loader.BundleLoader.setLazyTrigger(BundleLoader.java:265)
at org.eclipse.core.runtime.internal.adaptor.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:106)
... 22 more
Caused by: java.lang.ExceptionInInitializerError
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
at java.lang.Class.newInstance0(Class.java:372)
at java.lang.Class.newInstance(Class.java:325)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadBundleActivator(AbstractBundle.java:151)
... 28 more
Caused by: org.eclipse.swt.SWTException: Invalid thread access
at org.eclipse.swt.SWT.error(SWT.java:4083)
at org.eclipse.swt.SWT.error(SWT.java:3998)
at org.eclipse.swt.SWT.error(SWT.java:3969)
at org.eclipse.swt.widgets.Display.error(Display.java:1203)
at org.eclipse.swt.widgets.Display.checkDevice(Display.java:751)
at org.eclipse.swt.widgets.Display.getSystemColor(Display.java:2068)
at net.sf.simpletest.eclipse.SimpletestPlugin.<clinit>(SimpletestPlugin.java:65)
... 35 more

Answer 1

The reason is very clear. An exception was thrown when initializing a class, which is caused by accessing SWT Display in a non-UI thread.