When you execute 'open with lock', the following occurs :
If the specified file is already in the open mode, the program is suspended, and waits for exclusive availability of the file.
If the specified file is not in the open mode, the file is opened.
If the specified file is not in the open mode, the program is suspended, and waits for exclusive availability of the file.
If the specified file is in the open mode, the file is opened.