What are system calls?

Correct Answer: 1The hardware 2The operating system 3The application programs 4The users

Correct Answer: A real time process is a process that must respond to the eventswithin a certain time period A real time operating system is an operating system that can run realtime processes successfully

Correct Answer: Throughput : number of processes that complete their execution per time unit Turnaround time : amount of time to execute a particular process Waiting time : amount of time a process has been waiting in the ready queue Response time : amount of time it takes from when a request was submitted until the firstresponse is produced, not output (for time-sharing environment)

Correct Answer: In batched operating system the users gives their jobs to the operator who sorts the programs according to their requirements and executes them This is time consuming but makes the CPU busy all the time

Correct Answer: Paging is solution to external fragmentation problem which is to permit the logical address space of a process to be noncontiguous, thus allowing a process to be allocating physical memory wherever the latter is available

Correct Answer: Job queue Ready queue Device queue

Correct Answer: Java is one of the small number of languages that support at the language level for the creation and management of threads However, because threads are managed by the java virtual machine (JVM), not by a user-level library or kernel, it is difficult to classify Java threads as either user- or kernel-level

Correct Answer: User thread Kernel thread

Correct Answer: Deadlock is a situation where a group of processes are all blocked and none of them can become unblocked until one of the other becomes unblocked The simplest deadlock is two processes each of which is waiting for a message from the other

Correct Answer: Mutex is a program object that allows multiple program threads to share the same resource, such as file access, but not simultaneously When a program is started a mutex is created woth a unique name After this stage, any thread that needs the resource must lock the mutex from other threads while it is using the resource the mutex is set to unlock when the data is no longer needed or the routine is finished