title: COM dll called from PHP doesn't empty variables
body: <p>the problem I'm having started to appear lately and it doesn't appear everywhere.</p>
  <p>The front end (html/js) calls PHP pages. PHP in turn calls functions from a COM dll (vb6). The COM dll does use some lower level C++ .dlls in turns, though not sure this information is relevant.</p>
  <p>Now, lately (this did not happen before), in one specific COM dll function, let's call it <code>BringClients()</code>, sometimes (apparently some user concurrency happening - race condition?) a global variable let's say <code>ClientName</code> which is used within <code>BringClients()</code> is not empty when the function is called, but instead it holds a value, which is set on function <code>UpdateClients()</code> when this function is called in a completely different instance of the COM dll, by a completely different user.</p>
  <p>I don't know why this is happening. Aren't all COM dll variables empty when the .dll is initialized? I worked around it by manually emptying the variable on each initilization of the .dll, but should this even be happening? I haven't noticed a similar issue on other functions.</p>
  <p>The OS is Windows server with IIS.</p>