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POSpring synchronization issue
 

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    <p>I know that question about reusing prototype beans was asked many times, but my question means more than this.</p> <p><strong>What is the problem:</strong></p> <p>I start asynchronous tasks in handler (prototype bean) in for-lookup. but I can't start the next asynchronous task before the previous reach some milestone. So I have to proceed for-loop only after the previous task invokes a special method.</p> <p><strong>What the questions:</strong></p> <ol> <li><em>How to wait in for-loop before some method call in another bean?</em></li> <li><em>Can I invoke proceedLookUp() method of current prototype bean from another beans?</em></li> </ol> <hr> <pre><code>@Service(value = "Request.Start") @Scope("prototype") public static class Start { public Start() {} private Object lock; @Transactional public void handler(Request request, Response response) { for (int i = 0; i &lt; request.getAmount(); i++) { Utils.asyncProcessStart(); //Can't start the next async process before the previous rich some defined milestone lock.wait(); } } public void proceedLookUp() { lock.notify(); } } @Service public void AsynchronousTask { public void asyncAction() [ //Needed logic, before start the next async task getStartHandler().proceedLookUp(); } public void getStartHandler() { //HOW TO REWRITE NEEDED PROTOTYPE BEAN } } </code></pre> <p><strong>ADDITION:</strong></p> <p><em><strong>What is the problem</em></strong>: I use Activiti framework, which imply some restrictions. I should store some variables to a process (thread) context. I CAN write variables to a global context, BUT CAN'T write to a local process (thread) context before the process (thread) has been started. </p> <blockquote> <p>what you expect to happen, say if request.getAmount() returns 2?</p> </blockquote> <p>I should start two asynchronous processes in two different threads. Each process have <strong>the same set of variables</strong>. I must <strong>write appropriate variables to the local context of each process (thread)</strong>. But, I <strong>CAN'T</strong> do it <strong>before the process (thread) is started</strong> (due to the specific of Activiti framework).</p> <p>For example, each process (thread) should write "id" property to his own local context. I have <em>List ids</em> in <em>handler</em> method</p> <p>So, I should do the next sequence of actions:</p> <ol> <li>Write ids.get(0) as "id"-property to GLOBAL context</li> <li>Start the first process</li> <li>Hang on the for-loop</li> <li>[Inside the first process] write "id" property from global to local context (it is possible inside the first process)</li> <li>Notify appropriate Start bean that it can continue the for-loop</li> <li>Write ids.get(1) as "id"-property to GLOBAL context</li> <li>Start the second process</li> <li>Hang on the for-loop</li> <li>[Inside the second process] write "id" property from global to local context (it is possible inside the second process)</li> <li>Notify appropriate Start bean that it can continue the for-loop</li> </ol> <blockquote> <p>Why can't you just call it synchronously?</p> </blockquote> <p>As you have already understood, there is no guarantee that the first process (thread) write the "id"-property to it local context, before it has been overriden by for-loop for the second process (thread).</p>
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    1. COPlease, tell why you can't answer my question: is it too complex, I provided unsufficient amount of code or something else. There are 68 reviews and any comment!
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    2. COCan you draw a simple sequence diagram of what you expect to happen, say if request.getAmount() returns 2? Your handler method seems to be creating a new thread and running the asyncAction() method but then blocking. Why can't you just call it synchronously?
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    3. COAnswers to your question in ADDITION section of my question. If something not clear for you, please, ask me again
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