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copied!<p>"Better" depends on context. They are "equally powerful" according to James McParlane. I highly recommend viewing <a href="http://blog.metawrap.com/2004/11/09/semaphore-vs-monitor/" rel="nofollow noreferrer">his blog for a discussion on the differences</a>.</p> <p>Here is a quick guide I found:</p> <p><strong>Semaphores</strong></p> <ul> <li>Can be used anywhere in a program, but should not be used in a monitor </li> <li><code>Wait()</code> does not always block the caller (i.e., when the semaphore counter is greater than zero).</li> <li><code>Signal()</code> either releases a blocked thread, if there is one, or increases the semaphore counter.</li> <li>If <code>Signal()</code> releases a blocked thread, the caller and the released thread both continue.</li> </ul> <p><strong>Condition Variables</strong></p> <ul> <li>Can only be used in monitors</li> <li><code>Wait()</code> always blocks the caller.</li> <li><code>Signal()</code> either releases a blocked thread, if there is one, or the signal is lost as if it never happens.</li> <li>If <code>Signal()</code> releases a blocked thread, the caller yields the monitor (Hoare type) or continues (Mesa Type). Only one of the caller or the released thread can continue, but not both.</li> </ul> <p>This information from: <a href="http://www.cs.mtu.edu/~shene/NSF-3/e-Book/MONITOR/sema-vs-monitor.html" rel="nofollow noreferrer">http://www.cs.mtu.edu/~shene/NSF-3/e-Book/MONITOR/sema-vs-monitor.html</a></p> <p>Some useful resources:</p> <ul> <li><a href="https://stackoverflow.com/questions/34519/what-is-a-semaphore">What is a Semaphore</a></li> <li><a href="https://stackoverflow.com/questions/836301/looking-for-good-analogy-examples-for-monitor-verses-semaphore">Looking for Good Analogy Examples for Monitor Versus Semaphore</a></li> <li><a href="https://stackoverflow.com/questions/301160/what-are-the-differences-between-various-threading-synchronization-options-in-c">What are the differences between various threading synchronization options in C#?</a></li> </ul>

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