On Wednesday, March 14, 2007 12:20:20 AM -0700 Russ Allbery
<[EMAIL PROTECTED]> wrote:
Marcus Watts <[EMAIL PROTECTED]> writes:
Russ Allbery <[EMAIL PROTECTED]> writes:
Er, linking against pthread is very attractive to me on Linux. What am
I missing?
Depending on the version of linux (& glibc) you're more or less likely
to get a "different process" per thread, which affects things like
"kill", "wait", and "ps".
So it's just low-level weirdness along those lines? That doesn't really
bother me. (And hm, doesn't the new threading model not expose things
that way any more, or am I confused?)
You are not confused; it hasn't worked that way in some time, and even when
it did, it wasn't as bad as all that. Yes, multiple threads were
separately visible in ps (and still are, if you use the correct switch),
but waiting and signal delivery actually worked they way they should.
Also, it's not as true as all that even on amd64. On amd64, even by
default, non-pic executables link dynamically against pic shared
libraries. Non-pic executables can also be statically linked against
pic objects. What breaks is linking non-pic code into shared libraries
and objects.
Right, sorry. Yes, there are cases that are even more restrictive, but
that's the common one and the one that I'm the most concerned with, since
it's directly relevant to both Perl modules and PAM modules.
Indeed, on most machines, non-pic code in shared libraries is frowned
upon, and amd64 is merely enforcing a very common policy. It happens to
work with i386/gnu, and that's the real anomaly here.
I wouldn't describe this as "enforcing a policy". It's not just a policy;
there are technical reasons why putting non-PIC code in shared objects
doesn't work. Those just happen not to apply on some platforms, and I
think we all agree that there has been much bad practice as a result of
x86-linux being one of them.
A solution specific to AFS is only partly helpful, and nowhere near as
helpful as AFS starting to act like the rest of the world.
Agree. Largely that means providing archive and shared libraries with the
same names and ABI's, instead of requiring people to use different library
names depending on whether they want shared or archive libraries _and_
conflating that distinction with lwp-vs-pthread.
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