Kevin,
yes the mutex around proj.4 is necessary in order to guarantee correct
behaviour when several threads call proj.4 concurrently.
There are a few places in proj.4 where global variables are used. One of them
is the pj_errno variable / pj_strerrno() function.
There's an old discussion on t
I was profiling some code today with vtune, and it turned out that the
mutex around proj4 in gdal was the biggest culprit. I had code that
was calling Transform many times with one point at a time. I was able
to improve things a lot by calling it with multiple points, but
acquiring the mutex is sti
