module Netsys_pollset_generic:sig..end
val standard_pollset : unit -> Netsys_pollset.pollsetReturns a good standard implementation of pollset for this platform.
      It will be good for cases where only a small to medium number of
      descriptors is watched (several hundred should be ok). It is no problem
      when the pollset lives only for a short time. Also, it is not strictly
      necessary to call the dispose method after use.
On POSIX platforms, this returns a
      Netsys_pollset_posix.poll_based_pollset.
On Win32, this returns Netsys_pollset_win32.pollset in single-threaded
      programs, and a Netsys_pollset_win32.threaded_pollset in
      multi-threaded programs. Note that Win32 restricts the number of
      descriptors that can be watched per thread to 64. The threaded_pollset
      version overcomes this limit, but it is only available if your 
      program is compiled for multi-threading. Because of this, it may be
      useful to enable multi-threading for your program even when your code
      does not make use of it otherwise.
val performance_pollset : unit -> Netsys_pollset.pollsetReturns the best available pollset on this platform for high performance
      servers that have to deal with many different file descriptors. Note
      that this pollset may have higher initial costs, and may not be 
      suitable for cases where pollsets live only for a short time. Also,
      make sure the dispose method is called after use.
On some POSIX platforms this is backed by
      Netsys_pollset_posix.accelerated_pollset. See the documentation
      there for possible problems. If no better implementation is available,
      this is the same as standard_pollset.
val select_emulation : Netsys_pollset.pollset ->
       Unix.file_descr list ->
       Unix.file_descr list ->
       Unix.file_descr list ->
       float -> Unix.file_descr list * Unix.file_descr list * Unix.file_descr listlet select = select_emulation pset: Returns a function with the
      same meaning as Unix.select. It is emulated on top of pset.
Using the function is only recommended when the lists of file descriptors are short. Long lists impose a big performance penalty.
Unlike Unix.select the descriptors may be returned in any order.