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[[!meta copyright="Copyright © 2012 Free Software Foundation, Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
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Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license
is included in the section entitled [[GNU Free Documentation
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[[!tag open_issue_mig]]
# Originally in context of [[user/jkoenig/java]]
* [[tschwinge]] has to read about RMI and CORBA.
* MIG
* Hacking [[microkernel/mach/MIG]] shouldn't be too difficult.
* (Unless you want to make MIG's own code (that is, not the generated
code, but MIG itself) look a bit more nice, too.) ;-)
* There are also alternatives to MIG. If there is interest, the following
could be considered:
* FLICK ([[!GNU_Savannah_task 5723]]). [[tschwinge]] has no idea yet if
there would be any benefits over MIG, like better modularity (for the
backends)? If we feel like it, we could spend a little bit of time on
this.
* For [[microkernel/Viengoos]], Neal has written a RPC stub generator
entirely in C Preprocessor macros. While this is obviously not
directly applicable, perhaps we can get some ideas from it.
* Anything else that would be worth having a look at? (What are other
microkernels using?)
# IRC, freenode, #hurd, 2012-12-27
<braunr> i'll soon have userspace on x15, and begin system calls, and of
course IPC
<braunr> and, since i personally have a strong disgust for IDLs, i was
thinking of manually writing the RPC "stubs", with helper functions and
macros
<braunr> what do you think of that ?
<pinotree> IDLs could have the advantage you can generate any kind of
language output out of them
<youpi> I'd not recommend that
<youpi> as ugly as IDLs are, they are useful
<pinotree> maybe pick something with proper per-arch types and
structs... :)
<braunr> youpi: what feature do you consider that important in an IDL ?
<braunr> i mean important enough to want to keep it
<youpi> argument matching between client and server code
<braunr> well obviously, but system wide protocols such as the hurd's tend
not to change much
<youpi> we've still seen bugs about that
<youpi> even without changing the protocol
<braunr> pinotree: i agree about the language thing, but wrapping libraries
also do
<braunr> what IDL would you then recommend ?
<pinotree> corba! :p
* pinotree runs
<braunr> well don't run
<braunr> it's actually at the top of my list :p
<braunr> the parser is free, and allows writing custom backends
<braunr> and there is already support for many languages
* pinotree some time ago fixed omniorb in debian
<pinotree> (to compile on hurd, i mean)
<braunr> i thought i could delay this problem some more but it's actually
coming quite fast :/
<braunr> i suppose it would make sense to use an already popular IDL so
that support for other languages is readily available
<pinotree> and/or people already know it
<braunr> hm that's secondary imo
<braunr> it's not that hard to learn an idl (providing it's simple,
i.e. not mig-like)
<braunr> hm how about google protocol buffers ?
<pinotree> wow, not bad at a first glance (never seen it)
<pinotree> structs, optional fields, builtin strings
<braunr> the nice thing about it is that it focuses on serialization most,
but has basic rpc support that allows using whatever communication
channel you want
<braunr> it may still be overkill for a microkernel based system
<pinotree> otoh rpc is everything in a microkernel-based os
<braunr> when i say overkill, i mean too slow
<pinotree> we still have 1024-sized string_t...
<braunr> yes, mig is totally hairy ...
<braunr> hum, c++ only, no c :/
<pinotree> there seems to be a C compiler, install protobuf-c-compiler
<braunr> v0.15, doesn't seem widely used
<pinotree> even on 0.14 (currently in debian)
<braunr> it also seems to rely on contiguous messages, whereas i want
scatter-gather to be used with x15
<braunr> once more, i fell back on omg idl
<braunr> oh, there is also flick that looks interesting
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