radeon: Add protection against recursive DRM locking.

Reference counting protects DRM lock call from recursive locking that would
cause hang. Code also adds optional debugging output for recursive call that
is compiled only if NDEBUG is not defined.

This code is not 100% thread safe because mesa doesn't include increment and
test atomic operation. There is built-in gcc functions but they are only
available from gcc 4.2.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/radeon/radeon_common_context.h b/src/mesa/drivers/dri/radeon/radeon_common_context.h
index d7e94a6894..f8e1a25c9f 100644
--- a/src/mesa/drivers/dri/radeon/radeon_common_context.h
+++ b/src/mesa/drivers/dri/radeon/radeon_common_context.h
@@ -365,6 +365,7 @@ struct radeon_dri_mirror {
 
 	drm_context_t hwContext;
 	drm_hw_lock_t *hwLock;
+	int hwLockCount;
 	int fd;
 	int drmMinor;
 };