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.
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.
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.