help: is there any way to use integer 64 type in protocol?

[Jason Ekstrand]

On Sun, Apr 20, 2014 at 8:36 PM, Wang, Quanxian <quanxian.wang at intel.com>wrote:

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> *From:* Jason Ekstrand [mailto:jason at jlekstrand.net]
> *Sent:* Monday, April 21, 2014 6:32 AM
> *To:* Pekka Paalanen
> *Cc:* Wang, Quanxian; wayland-devel at lists.freedesktop.org
> *Subject:* Re: help: is there any way to use integer 64 type in protocol?
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> On Sun, Apr 20, 2014 at 1:17 PM, Pekka Paalanen <ppaalanen at gmail.com>
> wrote:
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>  On Sun, 20 Apr 2014 11:10:15 +0000
> "Wang, Quanxian" <quanxian.wang at intel.com> wrote:
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> > Hi,
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> > Is there any way to use type of integer 64bit in protocol?
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> No. You will have to use two 32-bit arguments, or propose a patch
> to add 64-bit types in a completely backwards-compatible way. I am
> not sure what the latter option would entail.
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> Adding 64-bit types wouldn't be too hard.  It would involve adding a
> int64_t an uint64_t types to wl_argument (I'd call them U and I personally)
> and adding code throughout libwayland to parse them.  In terms of backwards
> compatibility, it should be fine as long as you make it 100% clear that
> your new protocol extension uses the new 64bit types and therefore requires
> the newer libwayland version.
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> The other option is that you could do what Pekka did in the presentation
> extension and split it into two 32-bit parts.  What do you want to
> represent that needs a 64-bit type?
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> *[Wang, Quanxian] 32 is too short. Currently I use 32bit in Weston randr,
> it could only stand for 16 type of operations (every type use 2 bits,
> however 12 of 16 have been used.). It will be fine to use 64 bit or more
> for future extension. I will try to add a patch for that. Thanks for your
> comment.*
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As Thiago pointed out, we can't actually add that at this point (sorry, I
forgot about the 32-bit machine issue).  Also, if you're using a bitfield
and you think there's a reasonable chance of 32 bits being too small, then
there is probably also a reasonable chance of 64 bits being too small.  It
might be a good idea to consider other ways of representing it.  What
exactly are you representing in this bitfield?

Thanks,
--Jason Ekstrand


>   Thanks,
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> --Jason Ekstrand
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> The presentation extension could make use of a 64-bit type, too.
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> Thanks,
> pq
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