profile questions

Tue Aug 29 16:59:00 GMT 2006

Mathieu Lacage writes:
 > On Tue, 2006年08月29日 at 17:31 +0100, Andrew Haley wrote:
 > > Tom Tromey writes:
 > > > >>>>> "Andrew" == Andrew Haley <aph@redhat.com> writes:
 > > > 
 > > > >> I'd prefer to use dlmopen to solve this instead, but I'm not sure it
 > > > >> is actually suitable for our needs :-(
 > > > 
 > > > Andrew> I've heard you say so before, but you never said *why* you think it may
 > > > Andrew> not actually be suitable. Can you tell us?
 > > > 
 > > > Yeah, sorry. When loading a library into a new dlmopen namespace, I
 > > > wonder how other libraries needed by that library are handled. E.g.,
 > > > a BC-compiled .so will depend on libgcj_bc.so. I suppose it would try
 > > > to load a new copy of libgcj_bc.so into the new namespace... but this
 > > > is incorrect for our situation.
 > 
 > It will load a new copy of the library into the new namespace.
 > 
 > Another thing to keep in mind is that dlmopen has a static maximum
 > number of namespaces per process. On my FC5 system, that max number is
 > 15. (1 is used for the main namespace which leaves you 16 - 1 = 15 for
 > your own namespaces).
Aww, how annoying! I did try to trick dlopen() by making a hard link
to the shared object and using that, but dlopen() checks the
underlying inode. So we have to copy the whole shared library into
/tmp and dlopen() that... :-(
Andrew.