Milter-greylist

On Thu, 18 Feb 2016, Bob Friesenhahn bfriesen@... [milter-greylist] wrote:
>
> It seems that not writing the log file is due to an actual bug.
> Perhaps it needs to reserve a spare file descriptor or there is a more
> severe problem.
>
> There are only a couple of mail accounts here and it seems
> unreasonable that milter-greylist would be so busy to have exhausted
> all file descriptors (it did not look terribly busy at the time).

It seems that the problem is that the "stdio-hack" works by 
pre-acquiring (almost) 256 file handles and then doing:

         /* we have a low descriptor */
         close(descriptor);

         /* after releasing it, we hope the following fopen() call can aquire it ... */
         stream = fopen(path, mode);

It then tests if 'stream' uses the same descriptor as the one from the 
pool which was just closed.  The returned file handle should 
apparently still work, but the original has been lost from the pool. 
However, it did not seem like the file handle was actually usable 
since milter-greylist says it was not.

I will explore the preload hack described at:

http://www.oracle.com/technetwork/server-storage/solaris10/stdio-256-136698.html

and stop using --enable-stdio-hack.

Bob
-- 
Bob Friesenhahn
bfriesen@..., http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/