This is the mail archive of the cygwin mailing list for the Cygwin project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Multiple installations and 3PPs

On Fri, Jan 14, 2005 at 04:50:03PM +0000, Adrian Cox wrote:
>Multiple installations of Cygwin clash, both over the registry name
>used for the mount table and the name of the shared memory region.
>This makes it difficult to have several versions for testing purposes,
>and causes problems with software from 3PPs.

I don't know what "3PPs" (third party providers?) might be but there is
only supposed to be one version of cygwin1.dll in use on your computer
at a time.  The DLL even issues a rather verbose error when it detects
two versions running.

>Has anybody considered using PSAPI to find the full path to
>cygwin1.dll, and using a hash of this path as the name of the shared
>memory region and of the registry key?

This is rather like asking "Has anyone found a way to put sound
deadening foam over the little thing that chimes when you're not wearing
your seatbelt?"  The warnings are there for a reason, not because
we couldn't figure out how to name the shared memory region to avoid
clashes.  The problem isn't as simple as trying to avoid shared memory

The cygwin developers know how to keep multiple versions of cygwin
around for testing purposes so there really is no reason to add code
just to accommodate people who are apparently using cygwin for
commercial purposes without bothering to think too much about how they
are installing it.

Usually when people suggest that we should modify cygwin to accommodate
their needs they haven't investigated the options that are available to
them.  It is really not that difficult to switch between two different
versions by setting the path and using the "mount/unmount" commands.  That
should be adequate for testing purposes.

If someone is providing a product which installs cygwin then they should
be as polite as possible and not impact an existing installation.  This
requires them to understand how things work, however, and some providers
do not want to bother with that, leaving their hapless end-users to
figure things out.  That's not very good customer support for the the
third party product providers, but it is rather common.

That said, however, If someone has an idea for a tool for the
distribution that would make things easier for the people who just want
to shut their eyes and release the dll, then it will certainly be
considered.  It should be almost as simple as just running cygcheck to
see if cygcheck detects existing registry keys and then checking to see
that the cygwin DLL exists in the standard place.

>(I couldn't find anything with Google, but cygwin-developers isn't

That's because cygwin-developers is a private mailing list.


Unsubscribe info:
Problem reports:

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]