Test: Processes - Computer Science Engineering (CSE) MCQ

Those systems which allow more than one process execution at a time, are called multiprocessing systems. Uniprocessing means only one processor.

In UNIX, a new process is created by fork() system call. fork() system call returns a process ID which is generally the process id of the child process created.

Ready state of the process means process has all necessary resources which are required for execution of that process when CPU is allocated. Process is ready for execution but waiting for the CPU to be allocated.

Deadlock is a situation which occurs because process A is waiting for one resource and holds another resource (blocking resource). At the same time another process B demands blocking a resource as it is already held by a process A, process B is waiting state unless and until process A releases occupied resource.

wait() system call is used by the parent process to determine termination of child process. The parent process uses wait() system call and gets the exit status of the child process as well as the pid of the child process which is terminated.

Concept:
Process States in Operating System:
The process executes when it changes the state. The state of a process is defined by the current activity of the process.
The operating system's processes can be in any of the following conditions:
NEW:
The process is being created.
READY:
The process is waiting to be assigned to a processor.
RUNNING:
Instructions are being executed.
WAITING:
The process is waiting for some event to occur(such as an I/O completion or reception of a signal).
TERMINATED:
The process has finished execution.

Hence the correct answer is 5.

Concept:
Micro Instructions A sequencer is a collection of all devices used to pick the next micro-instruction location.

• The micro-instruction in control memory comprises a set of bits that launch micro-operations in computer registers as well as additional bits that define how the address is accessed.
• A microprogram sequencer generates the address of the next microinstruction to be executed.
• A sequencer or microsequencer generates the addresses used to step through the microprogram of a control store.
• It is used as a part of the control unit of a CPU or as a stand-alone generator for address ranges.

Hence the correct answer is to generate the address of the next microinstruction to be executed.

The size of the ready queue doesn’t depend on the number of processes. A single processor system may have a large number of processes waiting in ready queue  

Scheduling Algorithm:
shortest remaining time first
Gantt chart:

Process table:


Number of context switches = 2
Since initial is included 
Therefore total context switches = 1 + 2 = 3

The kernel keeps track of the state of each executing program by using a data structure called process control block.
Each process contains the process control block. PCB is the data structure used by the operating system. Operating system groups all the information that needs about a particular process.
STEPS :

1. An identifier is assigned to a new process.
2. Memory space is allocated for the process which includes program, data, stack, and PCB.
3. PCB is placed in the appropriate queue.
4. Other OS modules are notified about new processes i.e. create or expand other data structures to accommodate info about the new process.