On 3 April 2013 21:03, Greg Lazar <greglazar@hotmail.com> wrote:
The apr_file_lock routine, in the version of apr runtime library that I've currently built uses fnctl which does not appear to be thread safe. I need to use the worker MPM, so is it recommended that I build the apr runtime library to use flock instead. NFS file systems aren't a concern in this case. I didn't know how extensively the apr_file_lock was used through the rest of apache and if I'd be introducing any regressions by switching the apr runtime library to use flock.
 
Thank you.

Hi Greg,
I had brought this question up on the modules-dev mailing list a few months ago:

http://mail-archives.apache.org/mod_mbox/httpd-modules-dev/201109.mbox/%3CCAOM3y2i3osynN3Rnuvoqyhm1NHBgZTxxnt%2BT0y7nPz9tEpu6AA%40mail.gmail.com%3E

 Note that it would seem flock falls back to fcntl on some platforms, so using flock will not fix the issue on those platforms.

regards,
thomas