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    <p>The usual simple method of doing thread synchronization on a common resource or code block is to use a mutex (or, in this case, a critical section). Use the lock statement:</p> <p><a href="http://msdn.microsoft.com/en-us/library/c5kehkcz(VS.71).aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/c5kehkcz(VS.71).aspx</a></p> <p>This article says to do locking on the "this" pointer, but that can be dangerous, as outside callers could also acquire the same lock, which could break your program. Do your locking on a private class variable.</p> <p>Here is some modification of your example code to incorporate locking/a critical section:</p> <pre><code>class SomeClass : ISomeInterface { protected object ExecuteCommand(SvcCmdType cmdType, params object[] inputParams) { lock(executeCommandLock) { SvcCommandEventArgs eventArgs = new SvcCommandEventArgs(cmdType, inputParams); OnProcessingAppCommand(this, eventArgs); return eventArgs.OutputParamsList; } } private Object executeCommandLock = new Object(); } </code></pre> <p><strong>Edit:</strong></p> <p>(paraphrasing from comments). You mentioned that you might want to process all calls to ExecuteCommand on a single thread, asynchronously. You may be able to accomplish this with the Dispatcher class:</p> <p><a href="http://msdn.microsoft.com/en-us/library/system.windows.threading.dispatcher.aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/system.windows.threading.dispatcher.aspx</a></p> <p>Get a reference to the dispatcher on one thread. Pass that reference to the other threads. When those threads want to call ExecuteCommand, they use dispatcher.BeginInvoke. Since they use BeginInvoke, all calls to ExecuteCommand will then operate asynchronously, and not block on that thread. However, each version of ExecuteCommand will be queued up, and run sequentially dispatcher thread.</p>
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    1. CO@Cristi: Asynchronous calls are threads with wrappers around them. They still execute at the same time. If they share any state (any functions they call modify/read the same variables), you have to synchronize the threads/asynchronous calls. You can't simply test all the bugs away, either, because multi-threading is non-deterministic. Your app will only blow up under just the right (wrong) conditions. Due to murphy's law, this will happen on a client's machine in Antarctica.
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    2. CO@Cristi: As for synchronous vs asynchronous, you may still be able to support asynchronous if you somehow manage to give each thread/call it's own set of state. If they don't share anything, they can't break each other.
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    3. CO@Cristi: Depending on your code, you may be able to make the critical section much smaller, so you only block when multiple threads are trying to access that single resource.
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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