On 10/14/25 20:18, jijinbei wrote:
If we could gradually replace some of these with well-maintained
external ones, we could reduce maintenance cost and modernize the codebase.
For example:
* our own smart pointer implementations,
Hmm; the VclPtr<> stuff started off as a migration to std::shared_ptr -
but ... IIRC this was stymied at the last minute with the results we see today. The
existing code (and there is a lot of it) - has the habit of doing a lot of
referencing during initialization which creates significant aggravation here.
Find, debug and clean all that up, and we can switch to shared_ptr -
although we will prolly want to keep dispose() still. Quite probably that is
do-able by turning all constructor content into some 'initialize()' method with
the same parameters as a first step, and then making all constructors take no
state. Big mechanical change there - hopefully reasonably low risk; and can be
done incrementally - just make sure all OutputDevice derived constructors chain
immediately to an initialize() method with those parameters if they do not
already - then when done - make the cut-over.
https://git.libreoffice.org/core/+/refs/heads/master/vcl/README.lifecycle.md
Has details - see "One extra gotcha - an initial reference-count of 1"
which is the nub of the issue.
Ultimately the switch to having a hard & reliable lifecycle mechanism
to replace the nightmare of implicit ownership semantics, combined with some
horrible mix of shared_ptrs in some places made LibreOffice -much- easier to reason
about, debug, and ultimately made things like Collabora Online possible (I still
have too many scars from debugging the old approach =)
It was a nightmare change - that was extremely hard to keep working vs.
the cutting edge of the code since pre the new UI re-work from Caolan it was
everywhere. Thanks so much to Noel, Bubli and others IIRC for helping me out
getting it in, and cleaning up some of the follow-on problems.
HTH,
Michael.
--
Michael Meeks <>< CEO Collabora Productivity,
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