Plasma GitLab Archive
Projects Blog Knowledge

Module Netsys_pollset_generic

module Netsys_pollset_generic: sig .. end

val standard_pollset : unit -> Netsys_pollset.pollset

Returns 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.pollset

Returns 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 list

let 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.

This web site is published by Informatikbüro Gerd Stolpmann
Powered by Caml