+
+ set(CMAKE_REQUIRED_INCLUDES "${OPENSSL_INCLUDE_DIR}")
+ set(CMAKE_REQUIRED_LIBRARIES "${OPENSSL_LIBRARIES}")
+ check_function_exists(SSL_set_async_callback HAVE_OPENSSL_ASYNC)
+
+ if (HAVE_OPENSSL_ASYNC)
+ add_definitions(-DHAVE_OPENSSL_ASYNC)
+ endif()
+
+