On Tue, Dec 21, 2010 at 02:05:43PM -0800, Estabrook, Edward wrote: >On Dec 10 14:37, Estabrook, Edward wrote: >>> Generally I am seeking information regarding: >>> 1) Where can I download and install an older version of Cygwin (say >>> 1.5 era) to test if the problem is newly introduced? >> >> Corinna wrote: >What for? If it doesn't work on 1.5 you're exactly at the same spot as >>now. If it works on 1.5, we know it works on 1.5 but we still don't >>know why it doesn't work on 1.7, which means, you're still exactly at >>the same spot as now. So that's not really an option. The best option >>is either to debug the (slim) layer in Cygwin which provides send/recv, >>or at least to send an as-simple-as-possible, self-sufficient testcase, >>preferredly in plain C, which allows to reproduce the problem. > >Two reasons. If it works on 1.5, I'll simply use it to perform my testing >and the time-pressure to solve the root cause is lessened. >Whether it works or not, it'll tell me if the issue is a change between >those versions or something older. (Plus the build instructions and >distributed executable are for SIPp are written with cygwin 1.5 in mind. > >The setup-legacy installer for older versions of Windows is exactly what I >needed. I tested this out and confirmed the issue exists in the old version >as well. > >>> 2) What tools are available to measure potential packet loss within >>> cygwin itself? (the Windows stack is not reporting dropped UDP >>> packets, and the packets are not even making it into a locally running >>> instance of wireshark). Is there a way to dump / access / sniff the >>> inputs and outputs to the cygwin IP stack? Traffic volume is low so >>> verbosity would not pose a problem. >> >> Corinna wrote: >>You can add debug output to Cygwin's send and receive functions and use >>strace. > >OK, thanks. I see debug_printf() and syscall_printf() statements >sprinkled around the source. Where do these end up displayed / logged? >How are they enabled?
Via strace, as Corinna said. strace is a program which is somewhat similar to the linux program of the same name. "man strace" cgf -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
