I have been making use of Java's synchronized
blocks to make parts of my code thread safe. I am porting a data structure to java that can usually use synchronized
blocks, but I don't always know how to use them in a typical Java way.
Here is an example of one scenario:
myMethod (Bool useLock)
{
if (useLock)
{
//locks the following section of code until unlocked.
lockObject.lock();
}
//do more stuff....
if (useLock)
{
//unlocks exclusive control of code.
lockObject.unlock();
}
}
How do I do an equivalent of this in Java? In this code sometimes I want to lock and sometimes I don't, but I want to be smart about it and not have to write two versions of the same code. Are there other ways of locking in Java other than using synchronized
blocks?
Best Answer
You can use Lock objects, ReentrantLock in particular should do the work. http://docs.oracle.com/javase/tutorial/essential/concurrency/newlocks.html
Or you can still solve the issue with
synchronized
blocks. The code from your question will look like:Or if you want to guarantee the mutual exclusion among different instances of the class you should use other monitor object than
this
. For instanceTheClassName.class
or other explicitly defined static variable of that class.