On 01/04/11 01.07, dsimcha wrote:
== Quote from Jonas Drewsen (jdrew...@nospam.com)'s article
On 31/03/11 23.20, Max Klyga wrote:
On 2011-03-31 22:35:43 +0300, Jonas Drewsen said:
On 31/03/11 18.26, Andrei Alexandrescu wrote:
snip
I believe that we would need both the threaded async IO that you
describe but also a select based one. The thread based is important
e.g. in order to keep buffering incoming data while processing
elements in the range (the OS will only buffer the number of bytes
allowed by sysadmin). The select based is important in order to handle
_many_ connections at the same time (think D as the killer app for
websockets). As Robert mentions fibers would be nice to take into
consideration as well.
What I also see as an unresolved issue is non-blocking handling in
http://erdani.com/d/phobos/std_stream2.html which fits in naturally
with this topic I think.
I may very well agree mentoring if we get a solid proposal out of this.
I'm very glad to hear this. Now my motivation doubled!
/Jonas
Any comments, if this proposal be more focused on asyncronous networking
or should it address asyncronisity in Phobos in general?
I researched a little about libev and libevent. Both seem to have some
limitations on Windows platform.
libev can only be used to deal with sockets on Windows and uses select,
which limits libev to 64 file handles per thread.
Actually it seems the limit is OS version dependent and for NT it is
32767 per process: http://support.microsoft.com/kb/111855
Again forgive my naiveness, as most of my experience with concurrency is
concurrency to implement parallelism, not concurrency for its own sake.
Shouldn't
32,000 threads be more than enough for anything? I can't imagine what kinds of
programs would really need this level of concurrency, or how bad performance on
any specific thread would be when you have this many. Right now in my Task
Manager the program with the most threads is explorer.exe, with 28.
There doesn't have to be a thread for each socket. Actually many servers
have very few threads with many sockets each. 32000 sockets is not
unimaginable for certain server loads e.g. websockets or game servers.
But I know it is not that common.
/Jonas
