Re: [PATCH RFC] fork: reduce chances for "address space is already occupied" errors

[Brian Inglis <Brian dot Inglis at SystematicSw dot ab dot ca>]

On 2019-03-28 08:59, Michael Haubenwallner wrote:
> Hi Achim,
> 
> On 3/27/19 8:59 PM, Achim Gratz wrote:
>> Michael Haubenwallner writes:
>>> As far as I understand, rebasing is about touching already installed
>>> dlls as well, which would require to restart all Cygwin processes.
>>> As the problem is about some dll built during a larger build job,
>>> this is not something that feels useful to me.
>>
>> That's exactly why I introduced the "--oblivious" option several years
>> ago.  It'll let you rebase a set of DLL while benefitting from the
>> rebase database, but not recording them there, so if you later install
>> them properly there will be no collision.  I needed this for testing
>> newly compiled Perl XS modules, but you seem to have a similar use case.
> 
> What I can see so far is that right now there is only one single rebase
> database, in /etc/rebase.db.<arch>.
> 
> However, my 'installed' dlls are not put into /bin, but into the so called
> Gentoo "Prefix", e.g. /home/haubi/test-20190327/gentoo-prefix/usr/bin for
> example.  Remember that there can be multiple independent instances of Gentoo
> Prefix, so recording them all into the host /etc/rebase.db is not an option.
> 
> Hence there should be a rebase database per Gentoo Prefix instance, like
> /home/haubi/test-20190327/gentoo-prefix/etc/rebase.db.<arch>, to record
> my 'installed' dlls, while still loading the /etc/rebase.db.<arch> to avoid
> conflicts with cygwin provided dlls.
> 
> And how would one explicitly remove specific entries from the rebase database
> when dlls get uninstalled (by either package remove or package upgrade)?

Using rebase -O, --oblivious with -T, --filelist local-test-rebase-db gives you
your own local test rebase db - just add all your test dlls into it (sort -u to
eliminate dups).

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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