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    <p>The biggest question I have for you is architectural. Does the thread for each connection really need direct access to this array of <strong>other</strong> connections? Shouldn't they really be enqueueing abstract messages of some sort? If each connection thread is conscious of the implementation details of the universe in which it lives, I expect you will run into trouble somewhere down the line.</p> <p>But let's assume connection threads really do need direct access to each other...</p> <p>Global variables aren't inherently evil; schools just teach that because it's easier than providing a nuanced understanding. You do have to know the exact implications of a global variable, and it's a decent rule of thumb to assume that a global is the wrong choice until you discover you have no alternative. One alternative which solves a number of problems is to write a function like this: </p> <pre><code>SharedVector &amp; GetSharedVector (void) { static SharedVector sharedVector; return sharedVector; } </code></pre> <p>This buys you more control over when the class gets instantiated than you would have with a global variable, which can be critical if you have dependencies among global variables which have constructors, especially if those global variables spawn threads. It also gives you an opportunity to intercede when someone wants access to this "global" variable rather than just powerlessly suffer while they poke at it directly.</p> <p>A number of other thoughts also spring to mind. In no particular order...</p> <ul> <li>You doubtless already know the template syntax you use here is weird; I'll assume you just typed this code in without compiling it.</li> <li>You need a do-nothing assignment operator in your private section to prevent accidents (for the same reason you have a do-nothing copy constructor there).</li> <li>The explicit copy constructor is broken in a number of ways. It needs to explicitly copy the vector or you'll end up with an empty vector in your new instance of SharedVector. And it should simply initialize its own critical section rather than copy it (and then initialize it). Really for your case it probably doesn't make sense to have this function at all because network connections don't have reasonable copy semantics.</li> <li>You can make exception safety easier by creating a class EnteredCriticalSection whose constructor calls EnterCriticalSection and whose destructor calls LeaveCriticalSection. (It needs to hold onto a reference to the critical section, of course.) This makes it a ton easier to safely serialize your other member functions in the face of exceptions.</li> </ul>
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