Difference b/w "synchronized","synchronize",and "synchronized()"

[Bala_Rugan]

Hi,
could anyone tell me the difference b/w "synchronized","synchronize",and "synchronized()" and where these could be applied?

Also pls tell me about synchronize block and synchronize method. It's bit confusing to me:confused:.


Thanks in advance,
Bala

[neilcoffey]

You use synchronized in multi-threaded programming. To put it simply, only one thread at a time is allowed "into" the synchronized block. So for example, we can create a counter object shared among multiple threads as follows:

public class Counter {
  private int count = 0;
  public void increment() {
    synchronized (this) {
      count++;
    }
  }
  public int getCount() {
    synchronized (this) {
      return count;
    }
  }
}

A synchronized method looks as follows:

public synchronized void increment() {
  count++;
}

Making the method synchronized is essentially the same as saying "imagine that the entire code inside this method is written inside a synchronized block".

I stole this example from some more detailed information I wrote about the Java synchronized keyword, but you'll find a lot about the topic on line.

When should you use a sychronized block? Essentially, when you have code that reads or writes data that is shared among multiple threads (and if you haven't put some other protection in place -- there are actually other methods to make data threadsafe).


Note that there are a few disadvantages of declaring the method synchronized which more advanced programmers will want to consider.