Hi All,

I am looking for some APIs in window that have the smilar
functionalities provided by poll() or epoll() in Linux, for socket
programming.

Anyone have any idea??

Rajat.

I know in perl you can use select() on your sockets to check when they
are ready for reading/writing. After searching msdn it seams the
winsock has a select() function:

http://msdn.microsoft.com/library/de...k/select_2.asp

Hope that helps,
--K-sPecial

Rajat wrote:

> Hi All,
>
> I am looking for some APIs in window that have the smilar
> functionalities provided by poll() or epoll() in Linux, for socket
> programming.
>
> Anyone have any idea??

On Windows you need to use 'overlapped I/O' or 'I/O completion ports' to get the
same scalability.

> Rajat.

--
Phil Frisbie, Jr.
Hawk Software
http://www.hawksoft.com

(E-Mail Removed) wrote in message news:<(E-Mail Removed)>...
> I know in perl you can use select() on your sockets to check when they
> are ready for reading/writing. After searching msdn it seams the
> winsock has a select() function:
>
> http://msdn.microsoft.com/library/de...k/select_2.asp
>
> Hope that helps,
> --K-sPecial

Ya I too know about select(), but I wanted the same functionalities as
provided by poll() or epoll().

Don't poll and select do essentialy the same thing? Maybe I didn't
quite understand your question...

--K-sPecial

In article <(E-Mail Removed)>,
K-sPecial <(E-Mail Removed)> wrote:
on't poll and select do essentialy the same thing?

poll() can be used to get finer-grained information about the state
of a particular file descriptor; select() can be used to get cruder
information about a set of file descriptors.

See for example,
http://linux.com.hk/PenguinWeb/manpa...poll&section=2
--
How does Usenet function without a fixed point?

In article <cu71j8$i6$(E-Mail Removed)>,
(E-Mail Removed) (Walter Roberson) wrote:

> In article <(E-Mail Removed)>,
> K-sPecial <(E-Mail Removed)> wrote:
> on't poll and select do essentialy the same thing?
>
> poll() can be used to get finer-grained information about the state
> of a particular file descriptor; select() can be used to get cruder
> information about a set of file descriptors.

Poll() is also more efficient if there are lots of descriptors involved.
When select() returns, you have to search through all the descriptors
looking for the ones that became readable/writable, while poll() simply
returns the list of readable/writable descriptors.

--
Barry Margolin, (E-Mail Removed)
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***

In article <barmar-(E-Mail Removed)>,
Barry Margolin <(E-Mail Removed)> wrote:

>> poll() can be used to get finer-grained information about the state
>> of a particular file descriptor; select() can be used to get cruder
>> information about a set of file descriptors.
>
>Poll() is also more efficient if there are lots of descriptors involved.
>When select() returns, you have to search through all the descriptors
>looking for the ones that became readable/writable, while poll() simply
>returns the list of readable/writable descriptors.

More than that, a classic BSD kernel implementation of select() involved
sowakeup() to awakening all processes in the system stuck select() so
that each process can search its bit masks for a descriptor that
justifies returning to user mode. That works ok on a tiny system like
a VAX 780, but it's kind of slow on systems with lots of network jobs.
It's really painful on multi-processors with more than a trivial number
of CPUs because of the inter-CPU chatter required for locking file
descriptors and so forth.


Vernon Schryver (E-Mail Removed)

[comp.os.ms-windows.networking.* removed from followup list, since this
is now about POSIX and Unix APIs.]

In article <cu9a0c$2kt4$(E-Mail Removed)>, (E-Mail Removed) (Vernon Schryver) writes:
> In article <barmar-(E-Mail Removed)>,
> Barry Margolin <(E-Mail Removed)> wrote:
>
> >> poll() can be used to get finer-grained information about the state
> >> of a particular file descriptor; select() can be used to get cruder
> >> information about a set of file descriptors.
> >
> >Poll() is also more efficient if there are lots of descriptors involved.
> >When select() returns, you have to search through all the descriptors
> >looking for the ones that became readable/writable, while poll() simply
> >returns the list of readable/writable descriptors.
>
> More than that, a classic BSD kernel implementation of select() involved
> sowakeup() to awakening all processes in the system stuck select() so
> that each process can search its bit masks for a descriptor that
> justifies returning to user mode.

Agreed. poll also doesn't suffer from select's FD_SETSIZE limit.
FD_SETSIZE can be changed at compile time, but that's inflexible and
wastes space if the app frequently only has a few descriptors in the
set. Or an app can maintain its own dynamically-sized FD_SETs, but
then the FD_* macros won't work. And overflowing FD_SETs was
recently documented as a security hole in a number of applications.

--
Michael Wojcik (E-Mail Removed)

It does basically make you look fat and naked - but you see all this stuff.
-- Susan Hallowell, TSA Security Lab Director, on "backscatter" scanners