In this recipe, you will learn how to use one of the most basic methods of synchronization in Java, that is, the use of the synchronized keyword to control concurrent access to a method or a block of code. All the synchronized sentences (used on methods or blocks of code) use an object reference. Only one thread can execute a method or block of code protected by the same object reference.
When you use the synchronized keyword with a method, the object reference is implicit. When you use the synchronized keyword in one or more methods of an object, only one execution thread will have access to all these methods. If another thread tries to access any method declared with the synchronized keyword of the same object, it will be suspended until the first thread finishes the execution of the method. In other words, every method declared with the synchronized keyword is a critical section, and Java...
