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    <p>I'm not sure I understand the question correcly, but I usually use a <a href="http://download.oracle.com/javase/6/docs/api/java/util/concurrent/Future.html" rel="nofollow"><code>Future&lt;T&gt;</code></a> for these sorts of tasks.</p> <p>Internally the <code>Future&lt;T&gt;</code> implementation uses wait and notify and all of that, but the interface itself becomes rather clean.</p> <pre><code>Future&lt;Double&gt; getTemperature(int id); </code></pre> <p>In your communication code you then can map incoming messages towards unfulfilled futures. If ordering is guaranteed you could do something like</p> <pre><code>class Something { Map&lt;Integer, Queue&lt;Object&gt;&gt; requests; synchronized Future&lt;?&gt; request(int id, Object data) { MyFutureImpl future = new MyFuture(); requests.get(id).add(future); serializeAndSend(id, data); return future; } void serializeAndSend(id, data) {...} synchronized void response(int id, Object data) { MyFutureImpl future = requests.get(id).remove(); future.setValue(data); // This would fulfill the future, and any // threads waiting in a get() will get the // value and continue. } } </code></pre> <p>Where MyFutureImpl is a very basic future-implementation. I'm assuming there's a communications thread that calls <code>response()</code> when a packet is received. I'm also assuming that the <code>serializeAndSend()</code>-function handles the writing to the client or blocks until the write operation can be made or handed off to a communication thread.</p> <p>The use of concurrency-capable map and queue structures could make some <code>synchronization</code>s unnecessary. If there's only ever one outstanding call per id, the Queue becomes unnecessary of course.</p>
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    1. POBest way to synchronize asynchronous task
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    1. USHenrik Gustafsson
    1. USHenrik Gustafsson
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    1. COThank you for your idea. will have to walk through your code
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      1. USBigbohne
 

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