What is Garbage Collection in Java?
Garbage collection in Java allows the dynamic or automatic deallocation of unused code from the heap memory. It is one of the critical features of Java programming language. In contrast to C programming language, Java enables automated memory management, requiring minimum programmer involvement in freeing the unused memory space. If not the garbage collector, it needs the Java programmers to manage the memory space manually, requiring a time-consuming process and risk of generating error-prone tasks.
Steps involved in Garbage Collection:
To understand the Garbage Collection in Java in detail, we will discuss starting from code generation to memory allocation and memory deallocation.
The structure of Java programming includes a class declaration and a declaration of the main method. Within the main method, there is a step for object creation.
For example,
- Here, ‘e’ refers to the reference variable of the object.
- “new” is the keyword that helps create space in memory.
- Employee () is the constructor.
Whenever the programmer assigns a “new” keyword, it immediately allocates a new memory location known as a heap.
Next, the constructor, employee(), will start executing inside the allocated memory, making way for object creation.
- The created object stays inside the memory till the execution of the program.
- After compilation, the reference variable, ‘e,’ will be erased from the stack memory.
- However, the object stays inside the heap and continues to occupy the heap memory, subjecting it to the garbage collector.
As soon as it observes if there is any object residing in the heap memory without a reference variable, the garbage collector will make a call to the finalize method , indicating that the object can now be deallocated from the heap.
Then, the garbage collector in Java will dynamically deallocate the object from the heap memory.
The above process is performed automatically.
However, if the programmer wishes to perform garbage collection manually, the programmer can run the garbage collection explicitly or manually by invoking the code below,
System.gc() or runtime.gc()
However, even after writing the above code, there is no guarantee that there is an invoking of the garbage collector.
Because among the various threads, the garbage collector with the least priority may be last in the order.
What are the Benefits of Garbage Collection in Java?
Enhance Overall Programming Performance
Garbage collection in Java helps to deallocate unused objects from the memory automatically while providing extra free space for creating new objects. More free space in the memory enables the program execution to run faster.
Minimize Memory Leaks
Reclaiming unused memory helps provide sufficient memory for the program to run efficiently. In Java, the chances of insufficient memory usually do not occur because of the garbage collector.
Efficient Programming
Due to the garbage collector, memory management is simplified, with the programmers not required to manage it manually. Giving them extra time to concentrate on programming instead of worrying about the space allocation in the memory.