A fairly common pattern for debug envvars is something like:
static int should_print = -1;
if (should_print < 0)
should_print = env_var_as_unsigned("NIR_PRINT", 0);
Unfortunately helgrind doesn't realize that we expect to always get the
same return value, so we don't actually care about the race condition
here.
Add a helper get_once() and do_once macros, with extra locking to make
helgrind/drd happy. Note that other than the nir usages (which are
limited to debug builds), other usages are not in hot-paths.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7644>
Rob Clark
bda4d6e0d0