title: Blocking operations and ZeroMQ
body: <p>I'm designing a distributed system in which a single-threaded server processes perform a CPU intensive operation. These operations are triggered by ZeroMQ network messages.</p>
  
  <p>If the single-threaded process is performing the CPU intensive work, will the I/O (ZeroMQ sockets) block?</p>
  
  <p>Thanks!</p>