Synchronized sections are kind of like visiting your parents-in-law. You want to be there as little as possible. When it comes to locking the rules are the same – you want to spend the shortest amount of time acquiring the lock and within the critical section, to prevent bottlenecks from forming.
The problem with synchronized blocks is that they’re all or nothing – you can’t have more than one thread inside a critical section. This is especially a bummer in consumer / producer scenarios, where some threads are trying to edit some data exclusively, while others are only trying to read it and are fine with sharing access.
ReadWriteLocks were meant to be the perfect solution for this. You can specify which threads block everyone else (writers), and which ones play well with others for consuming content (readers). A happy ending? Afraid not.