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.

Related:

The Five Principles of Performance

In Demand IT Skills

As much as we love to assume free Wi-Fi is secure, this is far from the truth. Because you are attaching to a service many others are connected to as well, without security measures, your device can be hacked, especially if the network is unencrypted. Because this encryption involves handing out a 26-character hexadecimal key to every individual wanting to use that network, most places opt for ease of access over security. And even with a secure network, your information is vulnerable to everyone else who has the password and is on the network.

This may not seem like such a big deal and many people don’t believe they have anything to hide on their personal devices, but remember what you use on those devices. Chances are your e-mail is attached as well as all other social media sites. You may have apps that track your finances or private messages to certain others that you would never want anyone else to see. Luckily, there are steps that can be taken to reduce and prevent any unwanted information grabbers from accessing your personal information.

To start, go through your computer’s settings in order to verify your operating system’s security functions are all set to offer the highest protection. Open up the Control Panel and double check that your Firewall is enabled for both private and public networks. Then, go to Network and Sharing to open Change advanced sharing settings. In here, you can turn off file and printer sharing and network discovery for public networks.

One of the most important things to watch for is HTTPS. Hypertext Transfer Protocol Secure ensures secure communication across the web. Many of the major email systems use this when you log in (as another layer of password protection) but drop the security as soon as the login is complete. To keep this going, HTTPS Everywhere is a browser extension that gives you a secure connection when browsing some of the more popular sites. It can also be programmed for other sites you like to visit that don’t use HTTPS.

Not every place on the internet provides the choice of HTTPS, and VPNs are there to fill in the security gap. Virtual Private Networks allows data to be sent and received through public access points as if it were directly connected to a secure network. Many businesses offer this for company devices, but if you are an individual looking for that kind of security, ProXPN is a free version that can be upgraded. Unfortunately, it limits your speed, but other choices include VPNBook, OpenVPN Shield Exchange, and OkayFreedom.

With these three steps implemented, secure public Wi-Fi can be achieved. No longer will you have to worry about connecting in an unsure environment with strangers, never knowing if your information is being stolen. With all of the options free of charge, it is also an affordable means of protecting yourself that only takes a little time and effort to implement and guarantee safety.

In Demand IT Skills

Password Management Tools

Net Neutrality for the Layperson

What are a few unique pieces of career advice that nobody ever mentions?

This section of our beginning python training class always stumps students.  Firstly, because they need to know the difference between a function and a method.  Secondly, they need to understand object oriented programming concepts.  Thirdly, they need to realize that python has three types of methods.  Then they need to know how to use each method, which means they need to know the purpose of each method type.  Then they have to understand mutable versus non-mutable types.  The list goes on.  As part of our python tutorial, I hope to shed some light on this confusing topic.

To begin, the difference between a function and a method in python is that a method is defined within a class.  Here is an illustration:

#function

	def greeting():
	                print "Hello, I hope you're having a great day!"

	class HSGPrinter(object):
	                #method
	                def greeting(self): 
	                                print "Hello, I hope you're having a great day!"

As should be obvious, the second definition of greeting is encapsulated within the HSGPrinter class and is , therefore, refered to as a method.

The astute reader will notice that the greeting method contains one parameter named self.  For those who know C++ , Java or C#, self is equivalent to this i.e. it is a reference to the invoking object:

I remember the day like it was yesterday. Pac Man had finally arrived on the Atari 2600.  It was a clear and sunny day, but it was slightly brisk. My dad drove us down to the video store about three miles from our Michigan house. If I remember correctly, the price for the game was $24.99.  It was quite expensive for the day, probably equaling a $70 game in today’s market, but it was mine. There *was* no question about it. If you purchase a game, it’s your game… right?

You couldn’t be more wrong.  With all the licensing agreements in games today, you only purchase the right to play it. You don’t actually “own” the game. 

Today, game designers want total control over the money that comes in for a game. They add in clauses that keep the game from being resold, rented, borrowed, copied, etc. All of the content in the game, including the items you find that are specifically for you, are owned by the software developer. Why, you ask, do they do this? It’s all about the money.

This need for greed started years ago, when people started modifying current games on the market. One of the first games like this was Doom. There were so many third part mods made, but because of licensing agreement, none of these versions were available for resale. The end user, or you, had to purchase Doom before they could even install the mod.  None of these “modders” were allowed to make any money off their creation.