SOCKET_DATA_BLOCK_SIZE   49 maint/gnulib/tests/test-nonblocking-socket-child.c   main_reader_loop (test, SOCKET_DATA_BLOCK_SIZE, client_socket);
SOCKET_DATA_BLOCK_SIZE  114 maint/gnulib/tests/test-nonblocking-socket-main.c     main_writer_loop (test, SOCKET_DATA_BLOCK_SIZE, server_socket,