Why does strict alternation algorithm not hold progress?

answer: Strict alternation satisfies mutex – only the thread whose turn it is (determined by the turn variable) can access the shared data. It does not satisfy progress, as the approach forces P0 to always run after P1 and vice versa.

What are the requirements that a solution to the critical section problem must satisfy?

A solution to the critical section problem must satisfy the following three conditions:

• Mutual Exclusion. Out of a group of cooperating processes, only one process can be in its critical section at a given point of time.
• Progress.
• Bounded Waiting.

How does Peterson’s solution ensure that it will satisfy 3 requirements for a critical section problem?

The algorithm satisfies the three essential criteria to solve the critical-section problem. The while condition works even with preemption. The three criteria are mutual exclusion, progress, and bounded waiting.

What happens if a critical section algorithm does not implement progress?

Progress: If no process is executing in its critical section and some processes wish to enter their critical sections, then only those processes that are not executing in their remainder section can participate in deciding which will enter its critical section next, and this selection cannot be postponed indefinitely.

What is Dekker’s algorithm in operating system?

Dekker’s algorithm is the first known algorithm that solves the mutual exclusion problem in concurrent programming. Dekker’s algorithm is used in process queuing, and allows two different threads to share the same single-use resource without conflict by using shared memory for communication.

What are three conditions for a good solution of a critical section problem explain them in detail write down algorithm of the best solution?

Three must rules which must enforce by critical section are : 1) Mutual Exclusion 2) Process solution 3)Bound waiting. Mutual Exclusion is a special type of binary semaphore which is used for controlling access to the shared resource.

Why do we need process synchronization?

The need for synchronization originates when processes need to execute concurrently. The main purpose of synchronization is the sharing of resources without interference using mutual exclusion. The other purpose is the coordination of the process interactions in an operating system.

Does Peterson’s solution satisfies the bounded waiting and progress requirements?

It uses two variables that are turn variable and interested variable. Till now, each of our solution is affected by one or the other problem. However, the Peterson solution provides you all the necessary requirements such as Mutual Exclusion, Progress, Bounded Waiting and Portability.

Why is Peterson’s solution is a good solution for such critical section problem?

Peterson’s solution works for two processes, but this solution is best scheme in user mode for critical section. This solution is also a busy waiting solution so CPU time is wasted. So that “SPIN LOCK” problem can come. And this problem can come in any of the busy waiting solution.

What is strict alternation in operating system?

Turn Variable or Strict Alternation Approach is the software mechanism implemented at user mode. It is a busy waiting solution which can be implemented only for two processes. In this approach, A turn variable is used which is actually a lock. This approach can only be used for only two processes.

Why is critical section necessary critical section problem?

The critical section problem is used to design a set of protocols which can ensure that the Race condition among the processes will never arise.

What are the prerequisites for writing algorithms?

In order to write an algorithm, following things are needed as a pre-requisite: The problem that is to be solved by this algorithm. The constraints of the problem that must be considered while solving the problem. The input to be taken to solve the problem. The output to be expected when the problem the is solved.

How does input size affect the running time of an algorithm?

Most algorithms transform input objects into output objects. The running time of an algorithm or a data structure method typically grows with the input size, although it may also vary for different inputs of the same size. Also, the running time is affected by a lot of factors, such as the hardware environment and the software environment.

How to understand the algorithm to solve the critical section problem?

To understand the algorithm let’s understand the solution to the critical section problem first. The solution to critical section problem must ensure following three conditions: One of solution for ensuring above all factors is Peterson’s solution. Another one is Dekker’s Solution.

What is the use of constant time in algorithm analysis?

The constant function is useful in algorithm analysis, because it characterizes the number of steps needed to do a basic operation on a computer, like adding two numbers, assigning a value to some variable, or comparing two numbers. Executing one instruction a fixed number of times also needs constant time only.