Working of a Garbage Collector

• JVM triggers this process and as per the JVM garbage collection process is done or else withheld. It reduces the burden of programmer by automatically performing the allocation or deallocation of memory.
• Garbage collection process causes the rest of the processes or threads to be paused and thus is costly in nature. This problem is unacceptable for the client but can be eliminated by applying several garbage collector based algorithms. This process of applying algorithm is often termed as Garbage Collector tuning and is important for improving the performance of a program.
• Another solution is the generational garbage collectors that adds an age field to the objects that are assigned a memory. As more and more objects are created, the list of garbage grows thereby increasing the garbage collection time. On the basis of how many clock cycles the objects have survived, objects are grouped and are allocated an ‘age’ accordingly. This way the garbage collection work gets distributed.
• In the current scenario, all garbage collectors are generational, and hence, optimal.

Note: System.gc() and Runtime.gc() are the methods which requests for Garbage collection to JVM explicitly but it doesn’t ensures garbage collection as the final decision of garbage collection is of JVM only.

Knowing how the program and it’s data is stored or organized is essential as it helps when the programmer intends to write an optimized code in terms of resources and it’s consumption. Also it helps in finding the memory leaks or inconsistency, and helps in debugging memory related errors. However, the memory management concept is extremely vast and therefore one must put his best to study it as much as possible to improve the knowledge of the same.

This article will focus on Java memory management, how the heap works, reference types, garbage collection, and also related concepts.

Why Learn Java Memory Management?
We all know that Java itself manages the memory and needs no explicit intervention of the programmer. Garbage collector itself ensures that the unused space gets cleaned and memory can be freed when not needed. So what’s the role of programmer and why a programmer needs to learn about the Java Memory Management ? Being a programmer, you don’t need to bother with problems like destroying objects, all credits to the garbage collector. However the automatic garbage collection doesn’t guarantee everything. If we don’t know how the memory management works, often we will end up amidst things that are not managed by JVM (Java Virtual Machine). There are some objects that aren’t eligible for the automatic garbage collection.

Hence knowing the memory management is essential as it will benefit the programmer to write high performance based programs that will not crash, or if does so, the programmer will know how to debug or overcome the crashes.