Re: Writing to socket after shutdown

[Andy Wingo]

Hi Jon,

On Mon 02 Aug 2010 22:03, Jon Herron <address@hidden> writes:

>   I had an issue with a program recently where I tried to write to a socket 
> that 
> had been shutdown for transmission. This ends up causing guile to halt 
> without 
> any warning - no exceptions or backtrace available that I can see. I am using 
> guile compiled from master, but get the same results with 1.8.7. Is it 
> correct 
> to assume that I should be able to catch an exception under this 
> circumstance? 

I pasted your example at the REPL run via meta/gdb-uninstalled-guile and
got a SIGPIPE:

   Sent request...
   Shutdown socket for sending...

   Program received signal SIGPIPE, Broken pipe.
   0x000000324e40e42d in write () from /lib64/libpthread.so.0
   (gdb) c
   Continuing.
   Caught exception...
   system-error
   (fport_write ~A (Broken pipe) (32))
   scheme@(guile-user)> 

But the same thing does not work when run at a normal (not in GDB)
REPL. Hmm.

I think SIGPIPE is the right thing to do here; the problem is that Guile
does not appear to catch it by default. I'm not sure why the with-gdb
case is different from the normal case. Indeed adding the following line
does make it work:

  (sigaction SIGPIPE (lambda args (error "got a sigpipe, yo")))

Now, I guess the question is, what should happen when Guile gets a
signal? Should Guile install a signal handler by default? The current
situation is not particularly intuitive.

Andy
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