LockManager lock should work atomically

[fomich-artem]

Environment

General issue

Description of the bug

Method com.haulmont.cuba.core.app.LockManager#lock(java.lang.String, java.lang.String) has atomicity problem - between getting value from a map and putting them to it. I think is need to be used method "putIfAbsent" instead of "get" and "put" for example. In addition, if you look at the problem more deeply, then the question also arises of how to solve this in a clustered environment.

See:

cuba/modules/core/src/com/haulmont/cuba/core/app/LockManager.java

Line 126 in 81ab570

public LockInfo lock(String name, String id) {

Sorry for my english!