Re: Query regarding Branches in CVS

[Eric Siegerman]

On Fri, Apr 04, 2003 at 08:50:49PM +0530, Amit Sood wrote:
> Now if I have one file "ABC.txt" present in both branches,can I lock this
> file
> seperately for both the branches.This means if I have locked for main branch
> it is still unlocked for RELBRANCH1 and other way around.

I don't know.  CVS doesn't really do very well at locking files
or revisions so that only one person can make changes.  By the
way, a better term for this idea is "exclusive checkouts", to
distinguish this form of locking from other forms (one of which
I'll be talking about later).

The main goal of CVS was to avoid needing exclusive checkouts, so
that two (or more) people could work on the same file at the same
time.  That works well for text files, but for binary ones like
JPEGs, MS-Word docs, etc., one really wants exclusive checkouts.
But CVS's support for that is slim to none.

There are features like "watches" and "cvs edit" that people find
useful, but I don't really know much about them.

> Also if two users make changes to "ABC.txt" one user make
> changes to "ABC.txt" in main branch and other in RELBRANCH1 and
> these changes at exactly same moment of time will CVS will be
> able to handle such a scenario successfully.

Yes.  There are two issues, but CVS handles them both:
  - Keeping the two changes straight.  That's just what branches
    are for.  Someone who checks out the main branch, and someone
    else who checks out RELBRANCH1, will each get the "right"
    version.

  - Concurrent-update locking, to avoid corrupting the
    repository.  CVS does this; if both users commit their
    changes at the same moment, one of them will have to wait a
    short time for the other one's commit to finish.

--

|  | /\
|-_|/  >   Eric Siegerman, Toronto, Ont.        address@hidden
|  |  /
A distributed system is one on which I cannot get any work done,
because a machine I have never heard of has crashed.
        - Leslie Lamport