A threaded question

[Ericson James]

Hi,

I'm hoping that someone can help me. I'm developing with a webservice framework at the moment which allows me to call a method and pass the request String, along with an object which gets populated with data once the response has returned...

Sender.send(requestString, responseObject)

After calling the above method, the executing thread (Lets call it the MAIN thread) can carry on without waiting.

Sometime, a while after calling the above method I want the MAIN thread to wait and do nothing until this object has been populated. When it has been populated with certain parameters I want to continue execution. (Also, I dont have access to the thread which gets created somewhere within the method above)

Regards,
Eurig

[Jelle Klap]

First, let me get this out of the way, because I really think it needs to be addressed: why are you developing your own webservice framework?
If you are building yet another web service framework as an open-source/commercial alternative to existing frameworks, or just as a "fun little exercise", by all means feel free to ignore me.

However, if you feel you need to roll your own web service framework out of necessity, as part of a larger project, I'm curious about why existing frameworks don't meet your requirements? I'm not really up to speed on the latest developments of every available webservice framework out there, but I know aleast Apache Axis2 offers asynchronous web service support.

[Ericson James]

Jelle Klap wrote:First, let me get this out of the way, because I really think it needs to be addressed: why are you developing your own webservice framework?
If you are building yet another web service framework as an open-source/commercial alternative to existing frameworks, or just as a "fun little exercise", by all means feel free to ignore me.

However, if you feel you need to roll your own web service framework out of necessity, as part of a larger project, I'm curious about why existing frameworks don't meet your requirements? I'm not really up to speed on the latest developments of every available webservice framework out there, but I know aleast Apache Axis2 offers asynchronous web service support.

I'd rather not go off topic here. If you read correctly, I said I was developing with A web service framework. Axis2 is the framework. I don't want to go into web services here as the question itself is nothing to do with web services and I didn't want to put anyone off from answering the question if they didn't know Axis2 (or web services)

[Duc Vo]

Will something like below work for you?

int MAX_TIME_OUT = 100; //max of 10 seconds
int timewait = 0;

Sender.send(requestString, responseObject);
while (!responseObject.hasRequiredProps() && timewait <= MAX_TIME_OUT) {
     Thread.sleep(100); //sleep for 100 ms
     timewait ++;
}

[Mike Simmons]

This sounds like a good job for a CompletionService and a Future, from java.util.concurrent (JDK 5 or later). Use the CompletionService to hand a task off to a thread pool, returning a Future object which will eventually allow you to access the completed object. When you're ready to wait for the object to be available, call the Future's get() method, optionally with a timeout parameter.

Eurig wrote:(Also, I dont have access to the thread which gets created somewhere within the method above

That might be a problem. Do you have access to the code that creates the thread? Or to the code that populates the object? If not, it may be difficult to do this in a thread-safe manner. Or maybe you just meant that your code for the main thread doesn't have a reference to the worker thread? That's not a problem.

[Carey Evans]

I had a nice post written up about how you could do this yourself, then I noticed that javax.xml.ws.Response extends java.util.concurrent.Future. Axis2 implements JAX-WS, so this should be all you need.

[Jelle Klap]

Eurig Jones wrote:

Jelle Klap wrote:First, let me get this out of the way, because I really think it needs to be addressed: why are you developing your own webservice framework?
If you are building yet another web service framework as an open-source/commercial alternative to existing frameworks, or just as a "fun little exercise", by all means feel free to ignore me.

However, if you feel you need to roll your own web service framework out of necessity, as part of a larger project, I'm curious about why existing frameworks don't meet your requirements? I'm not really up to speed on the latest developments of every available webservice framework out there, but I know aleast Apache Axis2 offers asynchronous web service support.

I'd rather not go off topic here. If you read correctly, I said I was developing with A web service framework. Axis2 is the framework. I don't want to go into web services here as the question itself is nothing to do with web services and I didn't want to put anyone off from answering the question if they didn't know Axis2 (or web services)

Ah, misread, nevermind then

[Ericson James]

Thanks everybody,

I used the Completion service as part of the concurrency framework in the end