Re: how to avoid recv() blocking issue?

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when the non blocking socket is setup in blocking mode... I did specify
blocking socket.

With a non blocking socket, yeah, i dont know if any situation that would
make it block.


"Alexander Nickolov" <agnickolov@xxxxxxxx> wrote in message
news:u7VgazrAHHA.1780@xxxxxxxxxxxxxxxxxxxxxxx
Can you post the circumstances? I've never heard before
of a socket in non-blocking mode blocking in recv, at
least on a machine without third-party LSPs (all bets are
off if one has a third party LSP...).

Besides, it's not recommended even by Microsoft to ever
check the socket explicitly for data availablity! That
constitutes poor performance.

--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@xxxxxxxx
MVP VC FAQ: http://www.mvps.org/vcfaq
=====================================

"Chris Becke" <chris.becke@xxxxxxxxx> wrote in message
news:O1wISQkAHHA.4292@xxxxxxxxxxxxxxxxxxxxxxx
It is possible to be stuck in a blocking call to recv, and for the
server
to
drop the connection abnormally such that the blocking recv will never
exit.
I really dont see how that is happening in this situation.

However, because of that possibility, all my calls to blocking recv use
the
basic code:

first, use ioctlsocket(s,FIONREAD,&cbRead); to check if there is data
available.
If there is, go straight to recv, otherwise call
select(0,fd_s,0,0,&tv_timeout); with a timeout.

"Arkady Frenkel" <arkadyf@xxxxxxxxxxxxxxxx> wrote in message
news:esLEwWjAHHA.2140@xxxxxxxxxxxxxxxxxxxxxxx
That strange because WSAEventSelect() as WSAAsyncSelect do set socket
as
non-blocked. Check that you if you used them or through
ioctlsocket() with FIONBIO set to 1 on recv() you have to return with
WSAWOULDBLOCK warning or data
Arkady

"Alexander Cherny" <black@xxxxxxxxxxxxxxx> wrote in message
news:%23Wyf0XfAHHA.4292@xxxxxxxxxxxxxxxxxxxxxxx
hi all,

i got a problem with recv().

there's a thread to receive data from a server. periodically this
thread
has to stop (to let others to do some work). i created some events to
check them inside the thread. the problem happens, when recv() starts
and
does not receive any data from a server. this time the thread is
stuck -
recv() just waits for data, and i can't stop the thread well (not
using
TerminateThread() - btw, it's not a good idea, because a socket
remains
"anchored" by the thread).

is there any way to "unblock" recv() somehow? WSAEventSelect() does
not
help. looks like it's for different purposes.

thanks a lot.

--
alex c.









.

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