I will begin our blog on Java Tutorial with an incredibly important aspect of java development:  memory management.  The importance of this topic should not be minimized as an application's performance and footprint size are at stake.

From the outset, the Java Virtual Machine (JVM) manages memory via a mechanism known as Garbage Collection (GC).  The Garbage collector

• Manages the heap memory.   All obects are stored on the heap; therefore, all objects are managed.  The keyword, new, allocates the requisite memory to instantiate an object and places the newly allocated memory on the heap.  This object is marked as live until it is no longer being reference.
• Deallocates or reclaims those objects that are no longer being referened. 
• Traditionally, employs a Mark and Sweep algorithm.  In the mark phase, the collector identifies which objects are still alive.  The sweep phase identifies objects that are no longer alive.
• Deallocates the memory of objects that are not marked as live.
• Is automatically run by the JVM and not explicitely called by the Java developer.  Unlike languages such as C++, the Java developer has no explict control over memory management.
• Does not manage the stack.  Local primitive types and local object references are not managed by the GC.

So if the Java developer has no control over memory management, why even worry about the GC?  It turns out that memory management is an integral part of an application's performance, all things being equal.  The more memory that is required for the application to run, the greater the likelihood that computational efficiency suffers. To that end, the developer has to take into account the amount of memory being allocated when writing code.  This translates into the amount of heap memory being consumed.

Memory is split into two types:  stack and heap.  Stack memory is memory set aside for a thread of execution e.g. a function.  When a function is called, a block of memory is reserved for those variables local to the function, provided that they are either a type of Java primitive or an object reference.  Upon runtime completion of the function call, the reserved memory block is now available for the next thread of execution.  Heap memory, on the otherhand, is dynamically allocated.  That is, there is no set pattern for allocating or deallocating this memory.  Therefore, keeping track or managing this type of memory is a complicated process. In Java, such memory is allocated when instantiating an object:

String s = new String();  // new operator being employed
String m = "A String";    /* object instantiated by the JVM and then being set to a value.  The JVM
calls the new operator */

Getting involved with the IT, or Internet Technology industry, is a way for you to break into a variety of potential coveted career paths and job openings. Whether you prefer working with the back-end of programming or if you enjoy improve user experience while browsing online, there are many different in-demand IT skills that are useful to obtain today if you are seeking a career in the tech industry yourself.

Cloud Computing

Working with cloud computing, otherwise known as "the cloud", requires you to work within various types of servers that store and access data globally from any location. With the increase in mobile usage, cloud computing is becoming even more prevalent in today's society. When you want to work with cloud computing, understanding the basics of programming and network security is a must. Working in cloud computing is a way to help with building new applications, expanding companies online as well as allowing anyone internationally to locate and access a specific blog, website or mobile app.

UX Design

UX Design is also known as user experience design. A user experience designer specializes in understanding the usability and overall experience a web visitor has when browsing on a site or blog. UX design is essential to ensure that all visitors on a website are capable of navigating the blog properly and accessing the site's content with ease, regardless of the browser they are using or the type of device that is being used to access the site itself. Cross-browser compatibility and ensuring that all websites you are working with are accessible via mobile platforms is another responsibility of many UX designers today. Working in UX design is highly recommended if you believe you have an eye for "good" web design and if you have an interest in improving the overall experience web users for a specific audience have when visiting the blog or website you represent or that you are building for yourself.

IT Security

IT security is one of the fastest-growing positions throughout the entire IT industry and field. IT security requires you to understand network infrastructures as well as how to properly manage each server individually to provide security and protection from potential hackers and online thieves looking to steal sensitive data and information. Maintaining the security of a network and all servers for a company is only becoming more popular with the expansion of mobile phone usage along with the growth of the Internet altogether.

Understanding the variety of IT skills that are in demand today can help you to better decide on a path that is right for you. The more you understand about various IT skills, the easier it is to find a position or career in your future that is most suitable for the type of work you enjoy. Whether you are looking to develop new apps or if you are interested in managing the security of company servers, there are hundreds of positions and skills that are in demand in the IT industry today.

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In programming, memory leaks are a common issue, and it occurs when a computer uses memory but does not give it back to the operating system. Experienced programmers have the ability to diagnose a leak based on the symptoms. Some believe every undesired increase in memory usage is a memory leak, but this is not an accurate representation of a leak. Certain leaks only run for a short time and are virtually undetectable.

Memory Leak Consequences

Applications that suffer severe memory leaks will eventually exceed the memory resulting in a severe slowdown or a termination of the application.

How to Protect Code from Memory Leaks?

Preventing memory leaks in the first place is more convenient than trying to locate the leak later. To do this, you can use defensive programming techniques such as smart pointers for C++.  A smart pointer is safer than a raw pointer because it provides augmented behavior that raw pointers do not have. This includes garbage collection and checking for nulls.

If you are going to use a raw pointer, avoid operations that are dangerous for specific contexts. This means pointer arithmetic and pointer copying. Smart pointers use a reference count for the object being referred to. Once the reference count reaches zero, the excess goes into garbage collection. The most commonly used smart pointer is shared_ptr from the TR1 extensions of the C++ standard library.

Static Analysis

The second approach to memory leaks is referred to as static analysis and attempts to detect errors in your source-code. CodeSonar is one of the effective tools for detection. It provides checkers for the Power of Ten coding rules, and it is especially competent at procedural analysis. However, some might find it lagging for bigger code bases.

How to Handle a Memory Leak

For some memory leaks, the only solution is to read through the code to find and correct the error. Another one of the common approaches to C++ is to use RAII, which an acronym for Resource Acquisition Is Initialization. This approach means associating scoped objects using the acquired resources, which automatically releases the resources when the objects are no longer within scope. RAII has the advantage of knowing when objects exist and when they do not. This gives it a distinct advantage over garbage collection. Regardless, RAII is not always recommended because some situations require ordinary pointers to manage raw memory and increase performance. Use it with caution.

The Most Serious Leaks

Urgency of a leak depends on the situation, and where the leak has occurred in the operating system. Additionally, it becomes more urgent if the leak occurs where the memory is limited such as in embedded systems and portable devices.

To protect code from memory leaks, people have to stay vigilant and avoid codes that could result in a leak. Memory leaks continue until someone turns the system off, which makes the memory available again, but the slow process of a leak can eventually prejudice a machine that normally runs correctly.

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Sage wisdom states that there are two sides to every coin. This timeless wisdom will be borne out in spades with Windows 8/RT. Let's get into the dark side first.

If your users are veterans of Windows it is safe bet they are going to take one look at Windows 8 and scream blasphemy. Users whose brains are geared towards visual learning will undoubtedly yell the loudest and longest.

There's a good reason for this. Mick Jagger brought his band to the Redmond campus, performing live "Start Me Up" in the summer of 1995 (it was a great show). This heralded in the abandonment of program icons sitting on the desktop and introduced the now legacy Start button.

Ending the life of the 17-year-old start button is not going to go well with some users.