Few small changes for semaphore.c and util.h.

Add a ZERO_PTR() macro in util.h.
semaphore_destroy() will now ignore NULL pointers.

1 files changed, 2 insertions, 0 deletions

diff --git a/util.h b/util.h
index 470d3fd..28e42ba 100644
--- a/util.h
+++ b/util.h
@@ -25,4 +25,6 @@
 		if (result != ISC_R_SUCCESS) goto cleanup;	\
 	} while (0)
 
+#define ZERO_PTR(ptr, type) memset((ptr), 0, sizeof(type))
+
 #endif /* !_LD_UTIL_H_ */