Re: guile-1.8.1 - problems on AMD64

[Neil Jerram <neil@ossau.uklinux.net>]

ludovic.courtes@laas.fr (Ludovic Courtès) writes:

> I guess the point of this `_FORTIFY_SOURCE' thing is to help catch
> errors related to interactions with the kernel (among others).  The idea
> is that when performing a system call, one _should_ be concerned about
> its result.
>
> In the case of async.c:250, I don't understand whether/how failure of
> the `write ()' call should be handled.

I think it's writing a byte as an inter-thread signaling mechanism.
It's pretty unlikely that a single byte write will be interrupted, but
if it is then a retry will be needed, so I think the use of
SCM_SYSCALL is correct in principle here.

How about this, which is more similarly to the other uses of
SCM_SYSCALL in the code?

      SCM_SYSCALL (rv = write (sleep_fd, &dummy, 1));

(Whole patch is below.)

Regards,
     Neil


Index: async.c
===================================================================
RCS file: /cvsroot/guile/guile/guile-core/libguile/async.c,v
retrieving revision 1.86
diff -u -r1.86 async.c
--- async.c	17 Apr 2006 00:05:37 -0000	1.86
+++ async.c	19 Oct 2006 18:46:32 -0000
@@ -241,13 +241,14 @@
   if (sleep_fd >= 0)
     {
       char dummy = 0;
+      int rv;
       /* Likewise, T might already been done with sleeping here, but
 	 interrupting it once too often does no harm.  T might also
 	 not yet have started sleeping, but this is no problem either
 	 since the data written to a pipe will not be lost, unlike a
 	 condition variable signal.
       */
-      write (sleep_fd, &dummy, 1);
+      SCM_SYSCALL (rv = write (sleep_fd, &dummy, 1));
     }
 
   /* This is needed to protect sleep_mutex.



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