This is the mail archive of the
libc-help@sourceware.org
mailing list for the glibc project.
Re: timer_create Problem
On 5 Dec 2008, pavan savoy uttered the following:
> I am unable to understand, what support is where.
>
> I.e I am having problem building a application which has the system
> call timer_create, with sigev_notify as SIGEV_THREAD.
>
> Since this is a system call, basically the kernel should provide
> support for that kind of notification,
>
> However what I know is SIGEV_THREAD is not supported in the libC
> version I am using [its not even a glibC].
>
> So, when someone says there is no support for SIGEV_THREAD ? Is it not
> there in kernel ? Or not there in glibC ?
Applications almost never make system calls directly: they call wrappers
in the C library that make the call. So, yes, you need C library
support, and that's what the application is looking for.
> If there is support, in which file should I find that ? because its
> just system call, no wrappers around it or anything ? Isnt it ?
Even things with no libc frontend like vm86() have a trivial wrapper.
This issues a syscall using the vsyscall if available, or the
appropriate system-specific mechanism (e.g. int80) otherwise. This is
one of many reasons why new syscalls are somewhat discouraged: nobody
can use them (practically) until a new glibc is released that wraps
them.