This topic gets brought up occasionally and their are valid arguments to both sides. One reason we have hesitated to use dynamic libs is the partly due to freesurfers long release cycle (all subjects that are part of a study need to be performed all on the same version). This long release cycle sometimes necessitates fixes to a particular binary in the stream, which users are then free to use. Although this is a less than ideal release strategy, it is the reality of the situation. And if we linked against dynamic libs than any time a binary was updated, ALL those libs would need to be updated, which in turn would affect all binaries which link against them. I suppose only newly released binaries could be static, but their may be unintended consequences that Im not thinking of at the moment.
Im open to conversing about this, and appreciate any constructive feedback on improving our release model. But I would prefer to take the conversation offline as it gets overly technical rather quick.
-Zeke
On Sat, 20 Feb 2016, Bruce Fischl wrote:
hmmm, the only thing that worries me about dynamic linking is that it will add variability to the outputs. Zeke has spent endless amounts of time tracking down e.g. mac vs. pc differences in math libs and such. Won't dynamic linking just make that a much more prevalent problem?
nope -- I am not talking about dynamically linking external libraries ATM, but first about the internal ones, where the common code where instead of absorbing the same .a or .o blobs into multiple binaries, there would be a set of internal dynamic libraries which those binaries would be linked against, so there will no copies of binary code among different binaries. I guess https://www.gnu.org/software/automake/manual/html_node/Libtool-Convenience-L... is a quick intro into those.
As for linking against external libraries -- those could be bundled along with rpath pointing to their location or LD_LIBRARY_PATH override assuring they are picked up (instead of possibly available identically named system-wide ones).
So overall it is possible to achieve absent variability while using dynamic linking and allowing for possibility of the flexibility ;)
Cheers
Yaroslav O. Halchenko Center for Open Neuroscience http://centerforopenneuroscience.org Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755 Phone: +1 (603) 646-9834 Fax: +1 (603) 646-1419 WWW: http://www.linkedin.com/in/yarik _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer