Sharing my very old notes on operating system. Reliability: can be defined as the probability that a system will produce correct outputs up to some given time t. Reliability is enhanced by feature...

Here, we’ll be creating a simple data structure Queue, to demonstrate some of the functionalities of swift language, which includes: Value-type generics, Secure memory pointers, Mutating fu...

A list of interview topics for the developers, who are looking to hire or get hired for iOS work. These stuff are based on my experience while giving interviews or taking some for an iOS developer ...

Why did Apple introduce new programming language Swift instead of embracing an existing one like Java, Python, C++ one that already has community, exiting developers, and lots of resources? First ...

ZKLog Writing our own NSLog using c-function with variable length arguments. I’ve used fprintf() function to write on console, because it sends the formatted output to the stream, where printf() ...

Core Data A framework which manages, where data is stored, how it is stored, data caching, and memory management. It provides APIs to handle our data like insertion, update, deletion and for data ...

Handling Thread-Unsafe Shared Resource In the last post, we have discussed about creating thread-safe singleton objects. But creating a thread-safe singleton does not solve all the issues. If your...

First, lets have a look into the concepts of some Terminologies: Singleton A singleton class returns the same instance no matter how many times an application requests it. A typical class permits...

Problem (Features) Yeah, because what I feel is, everything starts with a Problem, when we face problems, issues. We put our thoughts, we start to work on it, we come up with some solutions, we bu...

Thread safe and Thread un-safe objects: Thread safe objects are safe to pass from one thread to another. On the other hand you may get stale value if you try to access a thread unsafe object wi...