Critical region is
Critical region is a set of instructions that access common shared resource which exclude one another in time. Critical region is primarily centred on the usage of global shared resources (or variables) among the processes.
Kernel is the set of primitive functions upon which the rest of operating system functions are built up.
At a particular time, the value of a counting semaphore is 10. It will become 7 after
1. 3 V operations
2. 3 P operations
3. 5 V operations and 2 P operations
4. 13 P operations and 10 V operations
P-denotes wait operation and V denotes signal. Value of counting semaphore initially 10, it will become seven by decreasing it by '3’ which can be done either by ‘3’ wait operation or 13 ‘P’- operation and ‘ 10’ V-operation, which effectively decreases the count by ‘3’.
In computers, especially IBM mainframes, a supervisor call (SVC) is a processor instruction that directs the processor to pass control of the computer to the operating systems supervisor program.
Semaphores are used to solve the problem of
1. Race condition
2. Process synchronization
3. Mutual exclusion
Semaphores are used in deadlock avoidance by using them during interprocess communication. It is used to solve the problem of synchronisation among processes.
Mutual exclusion problem occurs
Whenever process shared the common data and resources, there is a chance of violating the consistency among the data. This problem which is related to the global data is known as mutual exclusion.
Peterson’s algorithm is the solution of which of the following problem.
Peterson's algorithm restricts process entry. It ensures that the concurrent processes will enter alternatively into critical section. So, also solving problem of mutual exclusion.