getIOThreadMode -- get I/O thread mode

• Usage:

  getIOThreadMode()

  getIOThreadMode f

• Inputs:
  • f, a file,
• Consequences:

  • returns the I/O thread mode for the file f, or if no file is given, stdio, as an integer:
    • 0 for unsynchronized
    • 1 for synchronized
    • 2 for exclusive