RE: Lock timeouts revisited
We here at Microsoft must have locks without timeouts. This does not
mean that we should not implement locks with timeouts. Rather it means
there must be a way to specify "This lock has no timeout". As long as
that feature exists I am agnostic on the issue of timeouts.
>From: Ben Laurie [SMTP:firstname.lastname@example.org]
>Sent: Saturday, September 28, 1996 3:19 AM
>To: Jim Whitehead
>Subject: Re: Lock timeouts revisited
>Jim Whitehead wrote:
>> At the Cambridge meeting the issue of lock timeouts was discussed. I was
>> in favor of having locks which automatically timed-out after a given
>> duration, and the remainder of the participants were either neutral, or
>> somewhat opposed to the idea.
>> I'd like to revisit this issue, because discussions I've had about locking
>> since have convinced me that lock timeouts are a good thing, and we should
>> include them in the functionality we propose.
>> The compelling reasons for having lock timeouts stem from a consideration
>> of what to do when someone has a lock out, and then forgets about it, and
>> someone else needs the locked capabiity on the resource. This is a fairly
>> common occurrence.
>> Today, most systems allow someone to become a super user and then manually
>> remove the lock. Typically there are enough people around with super user
>> capability that removal of locks isn't a big problem. This practice does
>> depend on having access to the people with lock removal priviledges.
>> In a distributed authoring situation, it is likely that lock breaking
>> capability will be limited to a very few people. For example, in the case
>> of an Internet Service Provider maintaining a web space for hundreds of
>> people, it is likely there will only be very few employees of the ISP with
>> lock breaking capability, and they will not want to be bothered with this
>> Thus there is a need for a way to decentralize lock-breaking authority.
>> One solution to this problem is to have locks which time out, with an
>> adjustable timeout value. Some locks could time out every day, every hour,
>> or even after a week. This timeout value could be altered to meet the
>> needs of the local environment.
>Perhaps it would be worth considering a DHCP-style lock - where you establish
>a lock for a fixed period which can be renewed (without release)
>> - Jim
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