Re: 1.8 make check failing in popen.test

[Rob Browning]

Kevin Ryde <address@hidden> writes:

> I guess a select hang is probably the read-char waiting for the
> child to signal to the parent that it (the child) has closed stdout
> so the parent can go ahead and test that connection (for eof).
> Maybe gdb or some printfs can show if that's so.

I haven't had a chance to investigate much further yet, but if I run
make check under gdb and hit Ctrl-C while popen.test is hung, there
are two threads that were running.  The first thread's backtrace looks
like this:

#0  0xffffe410 in __kernel_vsyscall ()
#1  0x40281f41 in select () from /lib/tls/i686/cmov/libc.so.6
#2  0x400b481c in scm_std_select (nfds=29, readfds=0xbfa8621c, writefds=0x0, 
    exceptfds=0x0, timeout=0x0) at threads.c:1363
#3  0x4005f8ce in fport_fill_input (port=0x40647400) at fports.c:550
#4  0x40086aff in scm_fill_input (port=0x40647400) at ports.c:973
#5  0x40086c40 in scm_getc (port=0x40647400) at ports.c:991
#6  0x40088d7d in scm_read_char (port=0x0) at ports.c:948
#7  0x4005ad54 in ceval (x=0x404, env=0x40647188) at eval.c:4218

and the second thread's backtrace looks like this:

#0  0xffffe410 in __kernel_vsyscall ()
#1  0x401b681b in __read_nocancel () from /lib/tls/i686/cmov/libpthread.so.0
#2  0x40091923 in do_read_without_guile (raw_data=0x40b310d8) at scmsigs.c:134
#3  0x400b42fc in scm_without_guile (func=0x400918f0 <do_read_without_guile>, 
    data=0x40b310d8) at threads.c:657
#4  0x40091875 in signal_delivery_thread (data=0x0) at scmsigs.c:145
#5  0x400b67b5 in scm_c_catch (tag=0x104, 
    body=0x400917f0 <signal_delivery_thread>, body_data=0x0, 
    handler=0x400b6080 <scm_handle_by_message>, handler_data=0x400d867e, 
    pre_unwind_handler=0, pre_unwind_handler_data=0x0) at throw.c:204
#6  0x400b69c5 in scm_internal_catch (tag=0x104, 
    body=0x400917f0 <signal_delivery_thread>, body_data=0x0, 
    handler=0x400b6080 <scm_handle_by_message>, handler_data=0x400d867e)
    at throw.c:218
#7  0x400b55ad in really_spawn (d=0xbfa860c8) at threads.c:777

-- 
Rob Browning
rlb @defaultvalue.org and @debian.org; previously @cs.utexas.edu
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