title: Are the C functions recvfrom and sendto mutually exclusive?
body: <p>I have one thread calling <code>recvfrom</code> with a timeout of 100 ms in a loop.
  Another thread calls <code>sendto</code> periodically.</p>
  
  <p>Does the <code>sendto</code> function wait until the <code>recvfrom</code> is released by the timeout (or a successful read) or does it send the data during that period of time.</p>