Bug#231147: "Invalid argument" apr_proc_mutex_unlock error messages when restarting

[Björn Wiberg <bjorn.wiberg@home.se>]

Package: apache2-common
Version: 2.0.48-7

Using 'en2mod ssl' and the default ssl.conf provided by apache2-common
2.0.48-7, together with apache2-mpm-worker 2.0.48-7, I get the following
error messages in the error log when issuing 'apache2ctl -DSSL -k
graceful':

  [Wed Feb 04 20:58:21 2004] [notice] SIGUSR1 received.  Doing graceful
  restart
  [Wed Feb 04 20:58:21 2004] [emerg] (22)Invalid argument:
  apr_proc_mutex_unlock failed. Attempting to shutdown process gracefully.
  [Wed Feb 04 20:58:21 2004] [notice] Digest: generating secret for digest
  authentication ...
  [Wed Feb 04 20:58:21 2004] [notice] Digest: done
  [Wed Feb 04 20:58:22 2004] [notice] Apache configured -- resuming normal
  operations

After editing ssl.conf to replace the default "SSLMutex
file:/var/log/apache2/ssl_mutex" line with:

  SSLMutex fcntl:/var/log/apache2/ssl_mutex
  AcceptMutex fcntl

...and restarting (yields another of those error messages because when it
shuts down it is still using the "old" configuration)...

  [Wed Feb 04 20:58:36 2004] [notice] SIGUSR1 received.  Doing graceful
  restart
  [Wed Feb 04 20:58:36 2004] [emerg] (22)Invalid argument:
  apr_proc_mutex_unlock failed. Attempting to shutdown process gracefully.

...then restarting works just fine (shown a couple of times in a row
here):

  [Wed Feb 04 20:58:36 2004] [notice] Digest: generating secret for digest
  authentication ...
  [Wed Feb 04 20:58:36 2004] [notice] Digest: done
  [Wed Feb 04 20:58:37 2004] [notice] Apache configured -- resuming normal
  operations
  [Wed Feb 04 20:58:42 2004] [notice] SIGUSR1 received.  Doing graceful
  restart

  [Wed Feb 04 20:58:42 2004] [notice] Digest: generating secret for digest
  authentication ...
  [Wed Feb 04 20:58:42 2004] [notice] Digest: done
  [Wed Feb 04 20:58:44 2004] [notice] Apache configured -- resuming normal
  operations
  [Wed Feb 04 20:58:47 2004] [notice] SIGUSR1 received.  Doing graceful
  restart

  [Wed Feb 04 20:58:48 2004] [notice] Digest: generating secret for digest
  authentication ...
  [Wed Feb 04 20:58:48 2004] [notice] Digest: done
  [Wed Feb 04 20:58:48 2004] [notice] Apache configured -- resuming normal
  operations

My guess is that the default values used by apache2-mpm-worker may be
inappropriate (for usage with apache2-common's ssl.conf) in some way?

I tried the following, too:

  SSLMutex default
  AcceptMutex Default

...which should give as "default" settings as possible, but still got the
error messages. Whereas, as mentioned above, everything works just fine
using the fcntl mutex method.

Best regards,
Björn

--
Björn Wiberg (bjorn.wiberg@home.se)
Homepage: http://bwiberg.dyndns.org/