Instances of classes that implement either or both of the Lock and Condition interfaces of the java.util.concurrent.locks package are known as high-level concurrency objects. Using the intrinsic locks of such objects is a questionable practice even in cases where the code may appear to function correctly. Code that uses the intrinsic lock of a Lock object is likely to interact with code that uses the Lock interface. These two components will believe they are protecting data with the same lock, while they are, in fact, using two distinct locks. As such, the Lock will fail to protect any data.
Consequently, programs that interact with such objects must use only the high-level locking facilities provided by the interfaces; use of the intrinsic locks is prohibited. This problem generally arises when code is refactored from intrinsic locking to the java.util.concurrent dynamic-locking utilities.
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