Apache Reference: mod_ssl, SSLMutex
Semaphore for Internal Mutual Exclusion of Operations
Syntax: SSLMutex A
Example: SSLMutex file:logs/ssl_mutex
Since: Apache 1.3
This directive configures the SSL engine's global semaphore which is
used for mutual exclusion of operations that must be carried out, in a
synchronized way between the pre-forked Apache server processes. This
directive can be used only in the global server context, because
one global mutex is needed. The type argument can be
either ``none'' for no mutex (risky but works for most situations)
or ``file:filepath'' for using a lock file on the file system.
On some platforms, a third variant, ``sem'', is available
that uses a SysV IPC Semaphore (under UNIX) or a Windows Mutex (under
Win32).