CVSROOT: /cvs
Module name: src
Changes by: [email protected] 2019/10/03 00:10:54
Modified files:
libexec/ld.so : dlfcn.c library_subr.c loader.c resolve.c
resolve.h
Log message:
Use a better algorithm for calculating the grpsym library order.
The existing code did a full recursive walk for O(horrible). Instead,
keep a single list of nodes plus the index of the first node whose
children haven't been scanned; lookup until that index catches the
end, appending the unscanned children of the node at the index. This
also makes the grpsym list order match that calculated by FreeBSD and
glibc in dependency trees with inconsistent ordering of dependent libs.
To make this easier and more cache friendly, convert grpsym_list
to a vector: the size is bounded by the number of objects currently
loaded.
Other, related fixes:
* increment the grpsym generation number _after_ pushing the loading
object onto its grpsym list, to avoid double counting it
* increment the grpsym generation number when building the grpsym list
for an already loaded object that's being dlopen()ed, to avoid
incomplete grpsym lists
* use a more accurate test of whether an object already has a grpsym list
Prompted by a diff from Nathanael Rensen (nathanael (at) list.polymorpheus.com)
that pointed to _dl_cache_grpsym_list() as a performance bottleneck.
Much proding from robert@, sthen@, aja@, jca@
no problem reports after being in snaps
ok mpi@
