Re: bash doesn't send SIGHUP to children

[Emil]

On 4 September 2008, Chet Ramey <chet.ramey@case.edu> wrote:
> > Description:
> >     Regradless of the huponexit setting ('shopt -s huponexit' doesn't
> >         help) bash does not send SIGHUP to its children when it receives one
> >         itself. Previous version of bash 3.1.17 was behaving properly
> >         even with huponexit set to off
> > 
> > Repeat-By:
> >     launch rxvt, launch mc then close the rxvt window -> 
> >     mc is still running with CPU to 100% (this is because 
> >         mc tries to read from stdin while receiving EOF)
> >     Closing rxvt sends SIGHUP to bash but bash doesn't send
> >     SIGHUP to its children
> 
> Can you verify using a system call tracer that bash is not sending the SIGHUP?
> The default bash SIGHUP signal handler resends SIGHUP to all jobs, running or
> stopped, before exiting.

Hi Chet,

I did verify that with strace:

bash strace is:

29939 read(3, 0xbfc26ba4, 128)          = ? ERESTARTSYS (To be restarted)
29939 --- SIGHUP (Hangup) @ 0 (0) ---
29939 --- SIGCONT (Continued) @ 0 (0) ---
29939 sigreturn()                       = ? (mask now [])
29939 read(3,  <unfinished ...>

while mc tries to read in an infinite loop:

29948 read(0, ""..., 1)                 = 0
29948 select(1024, [0 4], NULL, NULL, {0, 100000}) = 1 (in [0], left {0, 
100000})
29948 select(1024, [0 4], NULL, NULL, NULL) = 1 (in [0])
29948 select(1024, [0 4], NULL, NULL, {0, 100000}) = 1 (in [0], left {0, 
100000})
29948 select(1024, [0 4], NULL, NULL, NULL) = 1 (in [0])

There is no signal passed to mc at all.

-- 
                                                                Regards,
                                                                Emil
--
I had one of them wooden computers once. Wooden keyboard,
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