Re: libpcap and select problem

[Ying Li <hellbunni () yahoo com>]

time out as in retval = 0
OS = redhat 9
I used ethereal to monitor traffic.

my server is suppose to send something to the client
using raw socket, use select/pselect with pcap to wait
for reply or resend last packet if timeout (retval
=0).
I reset(like putting tv_sec=0;tv_usec=1500; before
select) the value of timeval before call to
select/pselect each time.

Most of the time it works fine, but there are some
cases where my server sends 2 packets within 0.0001
seconds of each other, which shouldn't happen.  This
is when I set timeval.sec =0 and timeval.usec = 1500

The other weird thing is that the overall transfer
time of a bulk of data is 50%+ faster with these
timeout problems, as opposed to setting a longer
timeout or taking out the select()(i.e. server sends,
waits,  sends, assuming no packet lost) 
  

--- Guy Harris <guy () alum mit edu> wrote:

> On Oct 25, 2004, at 1:27 PM, Ying Li wrote:
>
> > Sometimes select() times out way too
> > fast, like 0.0001 seconds while my timevar is set
> to
> > 0.001 sec.
>
> "Times out" in the sense that "retval" is 0?
>
> On what OS are you doing this?
>
> -
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