Win95 problems revealed?

Chris Faylor cgf@cygnus.com
Fri May 19 23:28:00 GMT 2000


I may have figured out at least one of the long long long standing
problems with Windows 95.  The function GetThreadContext seems to
sometimes return bogus information.

This function is used by the signal handler code to figure out things
about the thread which is supposed to receive a signal.  In particular,
cygwin gets information concerning the stack pointer and current PC from
this function.  So, if the information is wrong, the results are
catastrophic.

I've really ripped the signal handler apart in the last few months and
this has been partly responsible for revealing the Windows 95 bug.  I
noticed the problem by running rxvt continuously on my Windows 95
system.  It would randomly cause a blue screen.

Liberal use of printfs pinpointed the problem.

I've worked around the problem in the current snapshot so I would be
interested in hearing if I have broken anything before I unleash this
on the world.

So, if you have negative experiences with the latest code on Windows 95
or NT, I'd like to hear about it.

Please send email to cygwin-developers with your experiences.

Thanks,
cgf


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