blocked with no lock record ?

[David Holmes]

<I added a subject line >

On 8/03/2012 4:57 PM, Le Huy wrote:
> Can some one explain me why in stacktrace of hotspot  I see a thread
> blocked without any information about lock record by mean what is
> blocking it.
>
> e.g.
>
> ---
>
>     3 "ajp-0.0.0.0-8029-1082" daemon prio=10 tid=0x63721000 nid=0x2cba
> waiting for monitor entry [0x4e619000]
>      4    java.lang.Thread.State: BLOCKED (on object monitor)
>      5         at java.lang.Class.forName0(Native Method)

Most likely the forName call is triggering class initialization and the 
thread is blocked on the monitor used to guard that (it is not a monitor 
associated with a Java level object hence no information in the 
stacktrace). Check if another thread is executing in the <clinit> for 
that class.

David Holmes
-----------

>      6         at java.lang.Class.forName(Class.java:186)
>      7         at
> com.my.security.SecurityMethodInterceptor$Rule.isAllowed(SecurityMethodInterceptor.java:102)
>      8         at
> com.my.security.SecurityMethodInterceptor.isAllowed(SecurityMethodInterceptor.java:163)
>      9         at
> com.my.security.SecurityMethodInterceptor.invoke(SecurityMethodInterceptor.java:140)
>     10         at
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
>     11         at
> org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
>     12         at
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
>     13         at
> org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
>     14         at $Proxy53.setPINValidated(Unknown Source)
>     15         at sun.reflect.GeneratedMethodAccessor285.invoke(Unknown Source)
>     16         at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
>     17         at java.lang.reflect.Method.invoke(Method.java:616)
>     18         at
> org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)
>     19         at
> org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
>     20         at
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
>     21         at
> org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)
>     22         at
> org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
>     23         at
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
>     24         at
> org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
>     ...
>     removed because it is not relevant
> ---
>
> Huy