He meant GLibC function, not syscall...
Posted Nov 30, 2010 22:56 UTC (Tue) by khim
In reply to: ABI backward-compatibility is the trick...
Parent article: The kernel and the C library as a single project
This is good example: sched_setaffinity(2) had two arguments before 2.3.4. If you'll take the old program which uses this version - you'll be unable to compile it today. BUT! If you'll take binary of old version of program compiled with old version of GLibC - it'll run with new one just fine because today GLibC offers two interfaces of sched_setaffinity(2) and selects them automatically depending on what the calling program expects.
GLibC maintains stable ABI - and it's very good at that (documented "undefined" behavior is exception, of course). Yet it does not maintain stable API! This experience is so alien compared to what other libraries are doing that it takes some time to wrap up the mind around the concept.
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