On Tue, Jan 13, 2009 at 05:44:51PM +0000, Daniel P. Berrange wrote:
There are a huge list of functions in POSIX which are not safe to use from multiple threads currently. I generated the list by looking at all libc symbol exports for variants which have a parallel _r symbol.
nm -D --defined-only /lib/libc.so.6 \ | grep '_r$' \ | awk '{print $3}' \ | grep -v __ \ | grep -v qsort \ | grep -v readdir \ | sort \ | uniq \ | sed -e 's/_r//'
The qsort one is a red herring, since you only need qsort_r if you need to pass a extra 'void * opaque' data blob to your sort function - we don't, so don't need qsort_r.
The readdir one is also unneccessary, since reading from a single DIR* is safe from a single thread. readdir_r is also horrific
http://womble.decadentplace.org.uk/readdir_r-advisory.html
This patch adds a 'make sc_prohibit_nonrentrant' rule to the 'syntax-check' for these forbidden functions.
.x-sc_prohibit_nonreentrant | 8 ++++ Makefile.am | 2 + Makefile.maint | 11 +++++ Makefile.nonreentrant | 85 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 106 insertions(+)
Yup, perfect, +1. Rich. -- Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://et.redhat.com/~rjones/virt-top