lock: support naming threads

Add support for naming threads under Unix. It's done with
pthread_setname_np(3) so we need to make sure it's available. On top of
that, we also need to compile lock.c with _GNU_SOURCE.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>

CMakeLists.txt

@@ -597,8 +597,13 @@ else ()
 
 		target_link_libraries(iio PRIVATE ${PTHREAD_LIBRARIES})
 	endif()
-
+	check_symbol_exists(pthread_setname_np "pthread.h" HAS_PTHREAD_SETNAME_NP)
+	if (HAS_PTHREAD_SETNAME_NP)
+		# still need to define _GNU_SOURCE for pthread_setname_np
+		set_source_files_properties(lock.c PROPERTIES COMPILE_FLAGS -D_GNU_SOURCE)
+	endif()
 	target_sources(iio PRIVATE lock.c)
+
 endif()
 
 if (IIOD_CLIENT OR WITH_IIOD OR WITH_LIBTINYIIOD)

lock.c

@@ -134,7 +134,12 @@ struct iio_thrd * iio_thrd_create(int (*thrd)(void *),
 		return iio_ptr(ret);
 	}
 
-	/* TODO: Set name */
+	if (HAS_PTHREAD_SETNAME_NP) {
+		ret = pthread_setname_np(iio_thrd->thid, name);
+		if (ret)
+			fprintf(stderr, "[WARNING]: Setting thread name(%s) failed\n",
+				name);
+	}
 
 	return iio_thrd;
 }