Package com.sun.xml.ws.api.pipe

Interface FiberContextSwitchInterceptor

public interface FiberContextSwitchInterceptor

Interception for Fiber context switch.

Even though pipeline runs asynchronously, sometimes it's desirable to bind some state to the current thread running a fiber. Such state may include security subject (in terms of AccessController.doPrivileged(java.security.PrivilegedAction<T>)), or a transaction.

This mechanism makes it possible to do such things, by allowing some code to be executed before and after a thread executes a fiber.

The design also encapsulates the entire fiber execution in a single opaque method invocation FiberContextSwitchInterceptor.Work.execute(P), allowing the use of finally block.

Author:

Kohsuke Kawaguchi

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	FiberContextSwitchInterceptor.Work<R,P>	Abstraction of the execution that happens inside the interceptor.

Method Summary

Modifier and Type	Method	Description
<R, P> R	execute(Fiber f, P p, FiberContextSwitchInterceptor.Work<R,P> work)	Allows the interception of the fiber execution.

Method Details

execute

<R,
P> R execute(Fiber f,
 P p,
 FiberContextSwitchInterceptor.Work<R,P> work)

Allows the interception of the fiber execution.

This method needs to be implemented like this:

 <R,P> R execute( Fiber f, P p, Work<R,P> work ) {
   // do some preparation work
   ...
   try {
     // invoke
     return work.execute(p);
   } finally {
     // do some clean up work
     ...
   }
 }
 

While somewhat unintuitive, this interception mechanism enables the interceptor to wrap the whole fiber execution into a AccessController.doPrivileged(PrivilegedAction), for example.

Parameters:

f - Fiber to be executed.

p - The opaque parameter value for FiberContextSwitchInterceptor.Work. Simply pass this value to FiberContextSwitchInterceptor.Work.execute(Object).

Returns:

The opaque return value from the the FiberContextSwitchInterceptor.Work. Simply return the value from FiberContextSwitchInterceptor.Work.execute(Object).