Top 10 List of Week 06

1. Processes In Operating System
   What is a process in operating system? It defines a program that is currently active. A process can be divided into four section, called code section, data section, heap section, and stack section. It also has a life cycle and control block. Check this site to see those.

2. Program vs Process vs Thread
   What are the differences between a program, a process, and a thread? A program is a set of instructions that resides on the disk. Then, a process is a program in execution. A thread is the smallest unit of execution in a process. A program of a process are often used interchangeably, but usually process is the one that is referred to.

3. Process Creation
   A process can be created because of user request for process creation, system initialization, or batch job initialization. fork() can be used to make another process by a process. Also, a process can be terminated with exit(). You can see come of the causes that can cause a process to terminate.

4. Process Scheduling
   Do you know that a process can be scheduled? It allows OS to allocate time interval of CPU execution for each process. With queues, processes are kept in there and ready to be executed. There also types of process schedulers, which are long term, medium term, and short term.

5. What is Context Switching?
   A CPU can switch from one task to another, and this is called context switching. Since it is executed very quickly, its user might think that all processes are executed at the same time. It can happen when a process with higher priority comes in the ready state or an interruption happens in the process of a running state. Read this article to see the steps of context switching and the advantages of it.

6. Dalvik vs ART, Which is Quicker for Android?
   Dalvik VM is a Java virtual machine developed by Dan Bornstein as part of the Android mobile platform. Meanwhile, ART or Android Runtime is the manage runtime used by applications and some system services on Android. Spoiler alert: ART wins by almost a second! How can this happen? In Dalvik, each process is executed in its isolated domain. However in ART, parallelized processing can happen making process execution runs faster.

7. Cooperating Processes vs Independent Processes
   Want to know the difference between cooperating and independent processes? See this site for more information! Independent process is a process that can’t be affected by other processes, while cooperating can. So why do need process cooperation? We need it for information sharing, computation speedup, modularity, and also convenience.

8. Single vs Multithreaded Process
   Single threaded processes contain the execution of instructions in a single sequence. In other words, one command is processes at a time. On the other hand, multithreaded processes can be implemented as user-level threads or kernel-level threads. Multithreaded process doesn’t mean that it doesn’t have any disadvantages. It is quite complicated and difficulte to handle, especially when we have to deal with concurrency. In this video you can see how a single and multithreaded process work.

9. Getting Started in Multicore Programming
   Ever heard of multicore programming? Multicore programming helps to create concurrent systems for deployment on multicore processor and multiprocessor systems. A multicore processor system is basically a single processor with multiple execution cores in one chip. It has multiple processors on the motherboard or chip. In this article, you can learn how to program with shared memory platform and decompose a program into parallel regions to speed up your computing process.

10. Multithreading Models in Operating System
    Multithreading models maps user threads to kernel threads. Just like in database entity relationships, there are three types of models, which are many to one, one to one, and many to many. For example for many to one model, more than one user thread in user space scheduler are mapped to one kernel thread in its kernel space. There are also many variations of these models, comprising the two level multithreading model.