• libuv
  • There is only one thread
  • Event loop runs in that one thread
  • Async work done by async I/O interfaces provided by most operating systems. Only when that is not available does node fallback to a thread pool (with 4 threads).
  • Event Loop Phases:
    1. Timers
    2. IO Callbacks
    3. IO Polling
    4. Set Immediate
    5. Close Events