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POChecking whether the current thread owns a lock
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copied!<p>Suppose I have the following code:</p> <pre><code>public class SomeClass() { private readonly object _lock = new object(); public void SomeMethodA() { lock (_lock) { SomeHelperMethod(); //do something that requires lock on _lock } } public void SomeMethodB() { lock (_lock) { SomeHelperMethod(); //do something that requires lock on _lock } } private void SomeHelperMethod() { lock (_lock) { //do something that requires lock on _lock } } } </code></pre> <p>Locking inside <code>SomeHelperMethod</code> seems redundant and wasteful, since all callers have already taken a lock. However, simply removing the lock from <code>SomeHelperMethod</code> seems dangerous since we might later refactor the code and forget to lock the <code>_lock</code> object prior to calling <code>SomeHelperMethod</code>.</p> <p>Ideally I could work around this by asserting that the current thread owns a lock on <code>_lock</code> inside <code>SomeHelperMethod</code>:</p> <pre><code>private void SomeHelperMethod() { Debug.Assert(Monitor.HasLock(_lock)); //do something that requires lock on _lock } </code></pre> <p>But there does not appear to be such a method. <code>Monitor.TryEnter</code> does <em>not</em> help because locks are re-entrant. Therefore, if the current thread already owns the lock, <code>TryEnter</code> will still succeed and return <code>true</code>. The only time it will fail is if another thread owns the lock and the call times out.</p> <p>So, does such a method exist? If not, why? It does not seem dangerous at all to me, since it merely tells you whether the current thread (not another thread) owns a lock or not.</p>

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