""Robert F. Tulloch"" <tultalk@...> wrote in message
news:3C55EE1C.3D53F215@......

> Hi:
>
> In IB source I can only find
>
> GUARDIAN_MUTEX = InterBaseGuardianMutex.
>
> Can't find mutex for IB Server.

Because you don't know where to look for it.
:-)

iscguard.c:
ControlService(hService, SERVICE_CREATE_GUARDIAN_MUTEX, &ServiceStatus);
Hey, engine, here's the mutex you want!

cntl.c
case SERVICE_CREATE_GUARDIAN_MUTEX:
hMutex = OpenMutex (SYNCHRONIZE, FALSE, GUARDIAN_MUTEX);
Ah, the guardian has the mutex ready to be used!

> What is mutex for FB and does FB use guardian?

The same mutex. You shouldn't be concerned probably, because IB & FB cannot
be run at the same time in the same machine and you're using IB.
FB can use the guardian. It will be useful in W9x and NT4. Why would a
person want the guardian in W2k if that OS restarts a failed service
automatically?

My take on this (and I'm only speaking for myself) is that the guardian is
the live recognition that we have a crashing engine. While it's not possible
to build the absolutely fail-safe engine, it can be made more robust. For
example, I only was able to crash MsSql when it was v6.5 and after that,
only crashed v7 with multiple connections doing chaotic operations on
bidirectional cursors. After the patch to v7 and in MsSql2k, I'm still
unable to crash the engine. Ah, of course, things are easier for MS that
only supports their own OS and have the sources for both artifacts (and they
have *a bit* more financial resources), but most of the IB crashes are
logical ones, not related to an specific OS.

C.
--
Claudio Valderrama C. - http://www.cvalde.com - http://www.firebirdSql.org
Independent developer
Owner of the Interbase® WebRing