nouveau: make nouveau importing global buffers completely thread-safe, with tests

While I've closed off most races in a previous patch, a small race still existed
where importing then unreffing cound cause an invalid bo. Add a test for this case.

Racing sequence fixed:

- thread 1 releases bo, refcount drops to zero, blocks on acquiring nvdev->lock.
- thread 2 increases refcount to 1.
- thread 2 decreases refcount to zero, blocks on acquiring nvdev->lock.

At this point the 2 threads will clean up the same bo.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@ubuntu.com>
Reviewed-By: Emil Velikov <emil.l.velikov@gmail.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index d5269f94..94fcc080 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -31,6 +31,10 @@ check_PROGRAMS = \
 	dristat \
 	drmstat
 
+if HAVE_NOUVEAU
+SUBDIRS += nouveau
+endif
+
 if HAVE_LIBUDEV
 
 check_LTLIBRARIES = libdrmtest.la