On Jan 1, 2008, at 19:41 , Tim Kientzle wrote:
Also, I'm wondering how other OSes handle this. I don't see this
code crash on Linux, contrary to its design as you say.
I would be curious to see the results of running your
sample program ... on Linux to see whether it calls the
registered exit function at dlclose time or never.
Linux pulls hidden atexit symbol into every binary that uses it ...
Linux calls atexit entries at object unload time.
Solaris implements a libc callback from ld.so.1 ...
Solaris calls atexit callback when removing it too.
Interesting. So the consensus here (at least for Linux
and Solaris, anyone know about Mac OS?) seems to be that
atexit() can be called from a dynamically loaded library
and that functions registered this way will be called
at library unload time.
And <sigh> FreeBSD doesn't implement this behavior.
Tim Kientzle
Mac OS X (10.5.1)
$ gcc -dynamiclib -o atexitmod.so atexitmod.c
$ gcc -o datest datatest.c
$ ./datest
hello driver
now exiting
$ uname -a
Darwin WideLoad.lan 9.1.0 Darwin Kernel Version 9.1.0: Wed Oct 31
17:46:22 PDT 2007; root:xnu-1228.0.2~1/RELEASE_I386 i386
$ gcc --version
i686-apple-darwin9-gcc-4.0.1 (GCC) 4.0.1 (Apple Inc. build 5465)
I guess Mac OS X calls atexit() somehow. I don't know the internals of
Mac OS X, just wanted to post that the example given in this thread
works as one would semi-expect, and thus possibly against the spec.
Bert JW Regeer
