Waylandsink - same buffer on multiple wl displays

Closes #1338 (closed)

This MR adds a unique WlBuffer context for each display to each WlBuffer, so that the same GstBuffer can be displayed on multiple waylandsink instances, each with their own connection to the wayland display.

mentioned in issue #1338 (closed)

In theory, as @ystreet said on the issue, if we add GstContext sharing through bins (I think waylandsink was written before this was added, not sure), all your waylandsink would share the same display, so a per display cache would make sense, reducing a bit the round-trips and possibly reducing spurious cache dma management (kernel overhead). So I think it's also a good place to store the cache.

I think waylandsink was written before this was added

Context sharing through bins has been there since GstContext was introduced.

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• dd7e7f69 - waylandsink: Keep per display wayland buffer caches

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Patch looks good, I really think lookup should be locked too, the rest is just nit suggestions.

changed milestone to %1.17.90

added Blocker label

@tpm I'd like this one in for the release.

go for it

So I'll just wait a little for @dhobsong's feeback on the comment back on the possible missing locking, and then we should be good to wrap.

@dhobsong any feedback ?

Yes, you're right, there should definitely be locking in gst_wl_display_lookup_buffer().
I'll add it and fixup the gst_ref_wl_buffer function name too.

added 1 commit

• a15f93cc - waylandsink: Keep per display wayland buffer caches

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@ndufresne I've pushed the updated commit.

added 2 commits

• f802d9ed - waylandsink: Keep per display wayland buffer caches
• b7451258 - waylandsink: use GstMemory instead of GstBuffer for cache lookup

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resolved all threads