Avoid synchronized(this) in Java?

Question

Whenever a question pops up on SO about Java synchronization, some people are very eager to point out that synchronized(this) should be avoided. Instead, they c

Answer 1

The java.util.concurrent package has vastly reduced the complexity of my thread safe code. I only have anecdotal evidence to go on, but most work I have seen with synchronized(x) appears to be re-implementing a Lock, Semaphore, or Latch, but using the lower-level monitors.

With this in mind, synchronizing using any of these mechanisms is analogous to synchronizing on an internal object, rather than leaking a lock. This is beneficial in that you have absolute certainty that you control the entry into the monitor by two or more threads.