quality@glassfish.java.net

Re: A deadlock during server instance's startup

From: Bring Zhang <bring.zhang_at_gmail.com>
Date: Mon, 4 Aug 2008 21:14:09 +0800

Hello Kedar Mhaswade,

Thanks for your reply.

> Zhang Biyun,
>
> Shridatta is probably not seeing this e-mail. It's quite possible that
> this code isn't thread-safe and like all threading bugs, this bug is
> uncovered only in some situations.
>
> The RMI TCP Connection thread is created when you send some
> request on the RMI/JMX Channel. It seems to come in the way of
> the main thread which isn't done yet (initializing the server).

i think so, thanks again.

> Can you attach the domain.xml and the entire stack trace in an e-mail?

The domain.xml and entire stack trace has been attached.

Thanks,
Zhang Biyun

> Thanks,
> Kedar Mhaswade
>
> Bring Zhang wrote:
> > Hello Sridatta Viswanath, GlassFish guys
> >
> > i encountered a deadlock during the the server instance's startup. The
> > GF version is V2 final release. From the stack trace(attached at
> > the end of the mail), it seems to be a bug which caused by ConfigBean API,
> > acting as bellow:
> >
> > * A sub thread named "RMI TCP Connection(14)-137.172.75.72"£¬ calls the
> > synchronized API com.sun.enterprise.config.ConfigBean#clone(), and locks
> > configbeans of config tree in fllowing order:
> >
> > Domain¡úResources
> >
> > * The main thread, calls the synchronized API
> > com.sun.enterprise.config.ConfigBean#getInterceptor(), and lock configbeans
> > in reverse order:
> >
> > Resources¡úDomain
> >
> > Is it a bug? With a greate interest, i looked into the implemention of the
> > synchronized API, and found the reason. The getInterceptor API performs as a
> > recursive call in special condition, and locks all configbean object during
> > its invocation period. The API does not release any lock until it returned.
> >
> > ////////////////////////////////////////////////////////////////////////////
> > public synchronized ConfigBeanInterceptor getInterceptor() { <------locks this
> > if (null != _interceptor) {
> > return _interceptor;
> > }
> > ConfigBeanInterceptor cbi = null;
> > //get interceptor of ctx.
> > if (null != ctx) {
> > /**
> > * Should have used the ConfigContext interface. Too late and
> > * risky to change the interface.
> > */
> > cbi = ((ConfigContextImpl)ctx).getConfigBeanInterceptor();
> > } else {
> > //get interceptor of parent.
> > ConfigBean parent = (ConfigBean)parent();
> > /*
> > Hack :- BaseBean.parent() returns 'this' if this is root.
> > Added the check (this != parent) to avoid recursion.
> > */
> > if ((null != parent) && (this != parent)) {
> > cbi = parent.getInterceptor(); <------lock parent
> > }
> > }
> > /*
> > if (null == cbi) {
> > cbi = EnvironmentFactory.getEnvironmentFactory().
> > getConfigEnvironment().getConfigBeanInterceptor();
> > }*/
> > //_interceptor = cbi;
> > return cbi;
> > }
> > ////////////////////////////////////////////////////////////////////////////
> >
> > Is the getInterceptor API thread safe? If not, how to fix?
> > When i tried to fix, i found it is really hard to do. How can i change the
> > method to be thread safe and do not do any bad influence? Could you give me
> > some suggestion?
> >
> > i also tried to sychronize the execution between
> > com.sun.enterprise.config.ConfigBean#clone() and
> > com.sun.enterprise.config.ConfigBean#getInterceptor() by creating a new
> > mutex, but this may cause a new deadlock.Because i do not know who would
> > call the API.
> >
> > Besides, i have another question where the sub thread "RMI TCP
> > Connection(14)-137.172.75.72" is started. Could u do me a favor?
> >
> > ////////////////////////deadlock stack trace showing bellow//////////////////////////////////
> > Found one Java-level deadlock:
> > =============================
> > "RMI TCP Connection(14)-137.172.75.72":
> > waiting to lock monitor 0x684286c4 (object 0x285ef8a8, a
> > com.sun.enterprise.config.serverbeans.Resources),
> > which is held by "main"
> > "main":
> > waiting to lock monitor 0x055e2464 (object 0x285d8638, a
> > com.sun.enterprise.config.serverbeans.Domain),
> > which is held by "RMI TCP Connection(14)-137.172.75.72"
> >
> > Java stack information for the threads listed above:
> > ===================================================
> > "RMI TCP Connection(14)-137.172.75.72":
> > at com.sun.enterprise.config.ConfigBean.clone(ConfigBean.java:553)
> > - waiting to lock <0x285ef8a8> (a com.sun.enterprise.config.serverbeans.Resources)
> > at org.netbeans.modules.schema2beans.BaseBean.clone(BaseBean.java:1294)
> > at com.sun.enterprise.config.ConfigBean.clone(ConfigBean.java:554)
> > - locked <0x285d8638> (a com.sun.enterprise.config.serverbeans.Domain)
> > at com.sun.enterprise.config.impl.ConfigContextImpl.clone(ConfigContextImpl.java:509)
> > at com.sun.enterprise.admin.event.AdminEventMulticaster.initEventHandler(AdminEventMulticaster.java:523)
> > at com.sun.enterprise.admin.event.AdminEventMulticaster.processEvent(AdminEventMulticaster.java:453)
> > at com.sun.enterprise.admin.event.AdminEventMulticaster.multicastEvent(AdminEventMulticaster.java:176)
> > at com.sun.enterprise.ee.admin.mbeans.ServerRuntimeMBean.forwardEvent(ServerRuntimeMBean.java:111)
> > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> > at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> > at java.lang.reflect.Method.invoke(Method.java:585)
> > at com.sun.enterprise.admin.MBeanHelper.invokeOperationInBean(MBeanHelper.java:375)
> > at com.sun.enterprise.admin.MBeanHelper.invokeOperationInBean(MBeanHelper.java:358)
> > at com.sun.enterprise.admin.runtime.BaseRuntimeMBean.invoke(BaseRuntimeMBean.java:462)
> > at com.sun.jmx.mbeanserver.DynamicMetaDataImpl.invoke(DynamicMetaDataImpl.java:213)
> > at com.sun.jmx.mbeanserver.MetaDataImpl.invoke(MetaDataImpl.java:220)
> > at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:815)
> > at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:784)
> > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> > at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> > at java.lang.reflect.Method.invoke(Method.java:585)
> > at com.sun.enterprise.admin.util.proxy.ProxyClass.invoke(ProxyClass.java:90)
> > at $Proxy1.invoke(Unknown Source)
> > at com.sun.enterprise.admin.server.core.jmx.SunoneInterceptor.invoke(SunoneInterceptor.java:304)
> > at com.sun.enterprise.interceptor.DynamicInterceptor.invoke(DynamicInterceptor.java:174)
> > at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1410)
> > at javax.management.remote.rmi.RMIConnectionImpl.access$100(RMIConnectionImpl.java:81)
> > at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1247)
> > at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1343)
> > at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:784)
> > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> > at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> > at java.lang.reflect.Method.invoke(Method.java:585)
> > at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:294)
> > at sun.rmi.transport.Transport$1.run(Transport.java:153)
> > at java.security.AccessController.doPrivileged(Native Method)
> > at sun.rmi.transport.Transport.serviceCall(Transport.java:149)
> > at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:466)
> > at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:707)
> > at java.lang.Thread.run(Thread.java:595)
> >
> > "main":
> > at com.sun.enterprise.config.ConfigBean.getInterceptor(ConfigBean.java:779)
> > - waiting to lock <0x285d8638> (acom.sun.enterprise.config.serverbeans.Domain)
> > at com.sun.enterprise.config.ConfigBean.getInterceptor(ConfigBean.java:798)
> > - locked <0x285ef8a8> (a com.sun.enterprise.config.serverbeans.Resources)
> > at com.sun.enterprise.config.ConfigBean.getInterceptor(ConfigBean.java:798)
> > - locked <0x286654a0> (a com.sun.enterprise.config.serverbeans.JdbcConnectionPool)
> > at com.sun.enterprise.config.ConfigBean.postGetAttributeValue(ConfigBean.java:828)
> > at com.sun.enterprise.config.ConfigBean.getAttributeValue(ConfigBean.java:539)
> > - locked <0x286654a0> (a com.sun.enterprise.config.serverbeans.JdbcConnectionPool)
> > at com.sun.enterprise.config.serverbeans.JdbcConnectionPool.getDatasourceClassname(JdbcConnectionPool.java:189)
> > at com.sun.enterprise.resource.ResourceInstaller.recoverJdbcXAResources(ResourceInstaller.java:512)
> > at com.sun.enterprise.resource.ResourceInstaller.recoverXAResources(ResourceInstaller.java:331)
> > at com.sun.enterprise.server.ApplicationLifecycle.onStartup(ApplicationLifecycle.java:205)
> > at com.sun.enterprise.server.ApplicationServer.onStartup(ApplicationServer.java:464)
> > at com.sun.enterprise.server.ondemand.OnDemandServer.onStartup(OnDemandServer.java:120)
> > at com.sun.enterprise.server.PEMain.run(PEMain.java:436)
> > at com.sun.enterprise.server.PEMain.main(PEMain.java:359)
> > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> > at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> > at java.lang.reflect.Method.invoke(Method.java:585)
> > at com.sun.enterprise.server.PELaunch.main(PELaunch.java:412)
> >
> > Found 1 deadlock.
> > ////////////////////////////end////////////////////////////////////////////////
> >
> > Have a nice weekend!
> >
> > Thanks,
> > Zhang Biyun
>
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