Re: [rfa/testsuite] Make pthreads test more robust

[Michael Snyder <msnyder at cygnus dot com>]

Daniel Jacobowitz wrote:
> 
> I've been seeing about 90% failure rate for gdb.threads/pthreads.exp lately.
> The test which fails is always stopping threads with a control-c.
> I spent some time debugging this today; it seems that the course of events
> looks something like this:
>         - send "continue\n"
>         - wait
>         - send "\003"
>         - read back "Continuing."
>         - timeout
> 
> Note that, among other things, we never see "continue\n" echoed back to us,
> and yet gdb continues anyway.  Obviously something is fishy in timing.  We
> also do no reads between the continue and the \003.  My best guess is that
> gdb does not get scheduled between the two sends; so waiting for the output
> of continue seems like a good idea.
> 
> Also, I'm not entirely sure what 'after 1000 [ ... ]' is supposed to do, but
> it doesn't seem to delay by any measurable amount of time.  Adding an
> additional sleep, so that the process has actually continued before we send
> the ^C, lets the test pass.
> 
> Is this OK to commit?  With it, the rest of pthreads.exp passes (except for
> the last test:
>       break common_routine thread 4
> Breakpoint 6 at 0x8048666: file ../../../../src-hashtest/gdb/testsuite/gdb.threads/pthreads.c, line 50.
> (gdb) PASS: gdb.threads/pthreads.exp: set break at common_routine in thread 2
>       continue
> Continuing.
> Cannot find thread 1024: generic error
> (gdb) FAIL: gdb.threads/pthreads.exp: continue to bkpt at common_routine in thread 2
> )

The patch looks sane.  I'd like Fernando's blessing, but I'm inclined
to suggest checking it in and just watching out to see if it breaks
on any other platform.


> 2001-09-28  Daniel Jacobowitz  <drow@mvista.com>
> 
>         * gdb.threads/pthreads.exp: Wait for output and delay
>         before sending ^C.
> 
> Index: pthreads.exp
> ===================================================================
> RCS file: /cvs/src/src/gdb/testsuite/gdb.threads/pthreads.exp,v
> retrieving revision 1.6
> diff -u -r1.6 pthreads.exp
> --- pthreads.exp        2001/06/06 18:34:53     1.6
> +++ pthreads.exp        2001/09/28 15:30:28
> @@ -248,6 +248,15 @@
> 
>      # Send a continue followed by ^C to the process to stop it.
>      send_gdb "continue\n"
> +    gdb_expect {
> +       -re "Continuing." {
> +           pass "Continue with all threads running"
> +       }
> +       timeout {
> +           fail "Continue with all threads running (timeout)"
> +       }
> +    }
> +    sleep 1
>      set description "Stopped with a ^C"
>      after 1000 [send_gdb "\003"]
>      gdb_expect {