[Info-vax] Ken Coar's OpenVMS Lock utility sources are available on Sourceforge.

[Craig A. Berry]

On 11/6/20 5:12 PM, Jon Pinkley wrote:
> On Friday, November 6, 2020 at 11:36:05 AM UTC-5, Stephen Hoffman wrote:
>> On 2020-11-05 08:03:00 +0000, Jon Pinkley said:
>>
>>> In 1998, Ken Coar submitted the LOCK utility to the DECUS VAXSIG tape.

>> More than a few other apps use lock files for this purpose, as that
>> tends to be somehwat more portable. And that approach can work from
>> DCL, too.

> I am showing my ignorance here, but how do you implement the
> equivalent of waiting for a lock with a lock file (queuing a lock
> request, $ENQ)?  I can understand how the equivalent of
> lock/nowait/mode=exclusive could be done with a lock file, but
> waiting?  It seems to me that would involve polling.

You wouldn't want to poll, but you might use select() or something from
the libevent library or similar.  Which are also non-portable.