Operating System

Long term scheduler controls by seeing whether new processes should be send for execution, if current processes have terminated.

In a real time operating system there is a boundation to complete the task at a given time, so most suitable is preemptive 

Here as we know, semaphore variable has value 1 and 0 so if s gets 1 then P has permitted it to enter into critical region.

Busy - Wait semaphore definition does not impose any ordering among waiting process, thus there is possibility that a process may be locked out due to contention with others. This process is known as live lock, thus FIFO keeps process in queue and hence no process gets starved.

Block everything that could possibly interfere so that nothing will interfere and this is known as pessimistic approach.

No of child process are (2^n -1), here n is equal to no. of fork () system calls.
So, 2^2 - 1 = 4 - 1 = 3
After a new process is created both child and parent processes will execute instruction following fork () system call.

Used with interactive processes.

When partition is static memory is wasted in each partition where an object of smaller size than the partition itself is loaded and is known as internal fragmentation.

Number of processes should be at least two.

These are powerful mechanism for mutual exclusion.

Medium term scheduler puts it in ready queue.

When we keep care we will get better and get true results because of interprocess synchronization and communication.

Here, p will take 1 unit then q will take 1 unit and gets completed then r will take 1 and then again p 1 and r  1 and then p 1 and then r 1 unit and gets completed again p will take 1 and hence, completely execute and total equals eight slice.

Monitors support both mutual exclusion data abstraction.

Busy- Wait semaphore definition does not impose any ordering among waiting process, thus there is a possibility that a process may be locked out due to contention with others.