I'd like to discuss a possible deadlock fix.
This happen when a thread which has a bundle lock has some reentrant call
while the global lock is held by another thread (see stack trace below)
In the code Felix#acquireBundleLock, the comment on the loop says "Wait if
the desired bundle is already locked by someone else or if any thread has
the global lock, unless the current thread holds the global lock or the
bundle lock already." which makes total sense, but I don't think the code
handle the case where the lock is already held by the current thread *and*
the global lock is held by a different thread.
Possible patch below.
diff --git a/framework/src/main/java/org/apache/felix/framework/Felix.java
b/framework/src/main/java/org/apache/felix/framework/Felix.java
index 6504f13..0965d8b 100644
--- a/framework/src/main/java/org/apache/felix/framework/Felix.java
+++ b/framework/src/main/java/org/apache/felix/framework/Felix.java
@@ -5002,7 +5002,8 @@ public class Felix extends BundleImpl implements
Framework
// holds the global lock or the bundle lock already.
while (!bundle.isLockable() ||
((m_globalLockThread != null)
- && (m_globalLockThread != Thread.currentThread())))
+ && (m_globalLockThread != Thread.currentThread())
+ && (bundle.getLockingThread() !=
Thread.currentThread())))
{
// Check to make sure the bundle is in a desired state.
// If so, keep waiting. If not, throw an exception.
"FelixStartLevel" daemon prio=5 tid=7fb1b2ac7800 nid=0x111144000 in
Object.wait() [111142000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <7e039bc90> (a [Ljava.lang.Object;)
at java.lang.Object.wait(Object.java:485)
at org.apache.felix.framework.Felix.acquireBundleLock(Felix.java:5025)
- locked <7e039bc90> (a [Ljava.lang.Object;)
at org.apache.felix.framework.Felix.registerService(Felix.java:3282)
at
org.apache.felix.framework.BundleContextImpl.registerService(BundleContextImpl.java:346)
at
org.apache.aries.blueprint.container.BlueprintContainerImpl.registerService(BlueprintContainerImpl.java:408)
at
org.apache.aries.blueprint.container.ServiceRecipe.register(ServiceRecipe.java:184)
at
org.apache.aries.blueprint.container.BlueprintContainerImpl.registerServices(BlueprintContainerImpl.java:666)
at
org.apache.aries.blueprint.container.BlueprintContainerImpl.doRun(BlueprintContainerImpl.java:334)
at
org.apache.aries.blueprint.container.BlueprintContainerImpl.run(BlueprintContainerImpl.java:230)
- locked <7f5898750> (a java.util.concurrent.atomic.AtomicBoolean)
- locked <7f5898740> (a java.util.concurrent.atomic.AtomicBoolean)
at
org.apache.aries.blueprint.container.BlueprintExtender.checkBundle(BlueprintExtender.java:325)
at
org.apache.aries.blueprint.container.BlueprintExtender.bundleChanged(BlueprintExtender.java:244)
at
org.apache.aries.blueprint.container.BlueprintExtender$BlueprintBundleTrackerCustomizer.modifiedBundle(BlueprintExtender.java:471)
at
org.osgi.util.tracker.BundleTracker$Tracked.customizerModified(BundleTracker.java:495)
at
org.osgi.util.tracker.BundleTracker$Tracked.customizerModified(BundleTracker.java:1)
at org.osgi.util.tracker.AbstractTracked.track(AbstractTracked.java:238)
at
org.osgi.util.tracker.BundleTracker$Tracked.bundleChanged(BundleTracker.java:457)
at
org.apache.felix.framework.util.EventDispatcher.invokeBundleListenerCallback(EventDispatcher.java:870)
at
org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:791)
at
org.apache.felix.framework.util.EventDispatcher.fireBundleEvent(EventDispatcher.java:515)
at org.apache.felix.framework.Felix.fireBundleEvent(Felix.java:4321)
at org.apache.felix.framework.Felix.startBundle(Felix.java:1945)
at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1213)
at
org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:295)
at java.lang.Thread.run(Thread.java:680)
--
------------------------
Guillaume Nodet
------------------------
Blog: http://gnodet.blogspot.com/
------------------------
FuseSource, Integration everywhere
http://fusesource.com
