[jetty-users] HttpClient.CONNECTOR_SOCKET and QueuedThreadPool in a mult

[Sachin Nikumbh <sanikumbh@xxxxxxxxx>]

Hi all

 

I am using Jetty 7.1.2.v20100523 and I am having problems while using HttpClient.  In a nut shell, my application is passing an instance of HttpClient to multiple user threads where each thread uses this instance to communicate with the same URL. I am using HttpClient.CONNECTOR_SOCKET  and a QueuedThreadPool. My application works only as long as the number of user threads that I am creating is less than the maximum umber of threads in the QueuedThreadPool. The moment number of user threads exceeds maximum number of threads in QueuedThreadPool , my application hangs. When I look in the debugger, I see that all the QueuedThreadPool threads are waiting in HttpConnection.handle method in the this.wait() call. They never seem to be getting notify’ed.
Is this a bug or am I missing something? Am I not supposed to use HttpClient.CONNECTOR_SOCKET in the way I am trying to.

Please refer the following code snippets for a better picture of the problem:

 

Following is how I am creating an instance of HttpClient in main:

QueuedThreadPool pool = new QueuedThreadPool(4);
pool.setDaemon(true);
pool.setMinThreads(2);
HttpClient jettyClient = new HttpClient();
jettyClient.setConnectorType(HttpClient.CONNECTOR_SOCKET);
jettyClient.setThreadPool(pool);
jettyClient.start();

As you can see, the QueuedThreadPool has maximum of 4 threads and minimum of 2 threads. I then create my user threads:

int numThreads = 20;
Vector<Thread> vThread = new Vector<Thread>();
for(int i=0;i<numThreads;i++){
    TestThread t = new TestThread(client);
    t.setName("TestThread"+i);
    vThread.add(t);
}
for(Thread t:vThread){
    t.start();
}
for(Thread t:vThread){
    t.join();
}

Following is a snippet from TestThread.run():

ContentExchange exchange = new ContentExchange();
exchange.setMethod("GET");
exchange.setURL("http://www.yahoo.com");
httpClient.send(exchange);  // httpClient is passed while constructing this instance of TestThread
exchange.waitForDone();
byte[] data = "">

System.out.println("Done");

 

When I run the application, only 3 TestThread's complete. The rest are hung on exchange.waitForDone(). Attaching a debugger shows that the hang is due to the QueuedThreadPool threads waiting to be notified.

Thanks in advance

Sachin