Anthro final
A binary semaphore is a semaphore with integer values : a) 1 b) -1 c) 0.8 d) 0.5
a) 1
A computer system has 6 tape drives, with 'n' processes competing for them. Each process may need 3 tape drives. The maximum value of 'n' for which the system is guaranteed to be deadlock free is : a) 2 b) 3 c) 4 d) 1
a) 2
In priority scheduling algorithm a) CPU is allocated to the process with highest priority b) CPU is allocated to the process with lowest priority c) Equal priority processes can not be scheduled d) None of the mentioned
a) CPU is allocated to the process with highest priority
A thread is also called : a) Light Weight Process(LWP) b) Heavy Weight Process(HWP) c) Process d) None of the mentioned
a) Light Weight Process(LWP)
To access the services of operating system, the interface is provided by the a) System calls b) API c) Library d) Assembly instructions
a) System calls
Multithreading an interactive program will increase responsiveness to the user by : a) continuing to run even if a part of it is blocked b) waiting for one part to finish before the other begins c) asking the user to decide the order of multithreading d) none of the mentioned
a) continuing to run even if a part of it is blocked
In the bounded buffer problem, there are the empty and full semaphores that : a) count the number of empty and full buffers b) count the number of empty and full memory spaces c) count the number of empty and full queues d) none of the mentioned
a) count the number of empty and full buffers
The circular wait condition can be prevented by a) defining a linear ordering of resource types b) using thread c) using pipes d) all of the mentioned
a) defining a linear ordering of resource types
Which module gives control of the CPU to the process selected by the short-term scheduler? a) dispatcher b) interrupt c) scheduler d) none of the mentioned
a) dispatcher
The two phase locking protocol consists of : a) growing & shrinking phase b) shrinking & creation phase c) creation & growing phase d) destruction & creation phase
a) growing & shrinking phase
___ is a mobile operating system designed for the iPhone and iPad a) iOS b) Mac OS X c) android d) UNIX e) Palm OS
a) iOS
The undo and redo operations must be _________ to guarantee correct behaviour, even if a failure occurs during recovery process. a) idempotent b) easy c) protected d) all of the mentioned
a) idempotent Idempotent - Multiple executions of an operation have the same result as does one execution
The process invoking the wait operation is : a) suspended until another process invokes the signal operation b) waiting for another process to complete before it can itself call the signal operation c) stopped until the next process in the queue finishes execution d) none of the mentioned
a) suspended until another process invokes the signal operation
The solution to starvation is : a) the number of rollbacks must be included in the cost factor b) the number of resources must be included in resource preemption c) resource preemption be done instead d) all of the mentioned
a) the number of rollbacks must be included in the cost factor
Suppose that a process is in "Blocked" state waiting for some I/O service. When the service is completed, it goes to the : a) Running state b) Ready state c) Suspended state d) Terminated state
b) Ready state
Which of the following scheduling algorithms gives minimum average waiting time ? a) FCFS b) SJF c) Round - robin d) Priority
b) SJF
The number of processes completed per unit time is known as __________ a) Output b) Throughput c) Efficiency d) Capacity
b) Throughput
The major difficulty in designing a layered operating system approach is___. a) Making sure that each layer hides certain data structures, hardware, and operations from high level layers b) appropiately defining the various layers c) debugging a particular layer d) Making sure each layer is easily converted to modules
b) appropiately defining the various layers
An un-interruptible unit is known as : a) single b) atomic c) static d) none of the mentioned
b) atomic
The two kinds of semaphores are : a) mutex & counting b) binary & counting c) counting & decimal d) decimal & binary
b) binary & counting
What is interprocess communication? a) communication within the process b) communication between two process c) communication between two threads of same process d) none of the mentioned
b) communication between two process
The segment of code in which the process may change common variables, update tables, write into files is known as : a) program b) critical section c) non - critical section d) synchronizing
b) critical section
The processes that are residing in main memory and are ready and waiting to execute are kept on a list called a) job queue b) ready queue c) execution queue d) process queue
b) ready queue
To _______ to a safe state, the system needs to keep more information about the states of processes. a) abort the process b) roll back the process c) queue the process d) none of the mentioned
b) roll back the process
If we preempt a resource from a process, the process cannot continue with its normal execution and it must be : a) aborted b) rolled back c) terminated d) queued
b) rolled back
The interval from the time of submission of a process to the time of completion is termed as a) waiting time b) turnaround time c) response time d) throughput
b) turnaround time
A minimum of _____ variable(s) is/are required to be shared between processes to solve the critical section problem. a) one b) two c) three d) four
b) two
The systems which allows only one process execution at a time, are called a) uniprogramming systems b) uniprocessing systems c) unitasking systems d) none of the mentioned
b) uniprocessing systems
Which one of the following can not be scheduled by the kernel? a) kernel level thread b) user level thread c) process d) none of the mentioned
b) user level thread
The signal operation of the semaphore basically works on the basic _______ system call. a) continue() b) wakeup() c) getup() d) start()
b) wakeup()
To ensure difficulties do not arise in the readers - writers problem, _______ are given exclusive access to the shared object. a) readers b) writers c) readers and writers d) none of the mentioned
b) writers
A Process Control Block(PCB) does not contain which of the following : a) Code b) Stack c) Bootstrap program d) Data
c) Bootstrap program
In UNIX, the return value for the fork system call is _____ for the child process and _____ for the parent process. a) A Negative integer, Zero b) Zero, A Negative integer c) Zero, A nonzero integer d) A nonzero integer, Zero
c) Zero, A nonzero integer
Termination of the process terminates a) first thread of the process b) first two threads of the process c) all threads within the process d) no thread within the process
c) all threads within the process
If no process is suspended, the signal operation : a) puts the system into a deadlock state b) suspends some default process' execution c) nothing happens d) the output is unpredictable
c) nothing happens
A thread shares its resources(like data section, code section, open files, signals) with : a) other process similar to the one that the thread belongs to b) other threads that belong to similar processes c) other threads that belong to the same process d) all of the mentioned
c) other threads that belong to the same process
A process is selected from the ______ queue by the ________ scheduler, to be executed. a) blocked, short term b) wait, long term c) ready, short term d) ready, long term
c) ready, short term
The state of the data accessed by an aborted transaction must be restored to what it was just before the transaction started executing. This restoration is known as ________ of transaction
c) roll - back
A system is in a safe state only if there exists a : a) safe allocation b) safe resource c) safe sequence d) all of the mentioned
c) safe sequence
Which one of the following is a synchronization tool? a) thread b) pipe c) semaphore d) socket
c) semaphore
The request and release of resources are ___________ a) command line statements b) interrupts c) system calls d) special programs
c) system calls
The kernel is _______ of user threads. a) a part of b) the creator of c) unaware of d) aware of
c) unaware of
The following three conditions must be satisfied to solve the critical section problem : a) Mutual Exclusion b) Progress c) Bounded Waiting d) All of the mentioned
d) All of the mentioned
Which of the following is FALSE ? a) Context switch time is longer for kernel level threads than for user level threads b) User level threads do not need any hardware support c) Related kernel level threads can be scheduled on different processors in a multiprocessor system d) Blocking one kernel level thread blocks all other related threads
d) Blocking one kernel level thread blocks all other related threads
Each process Pi, i = 0,1,2,3,......,9 is coded as follows repeat P(mutex) {Critical Section} V(mutex) forever The code for P10 is identical except that it uses V(mutex) instead of P(mutex). What is the largest number of processes that can be inside the critical section at any moment (the mutex being initialized to 1)? a) 1 b) 2 c) 3 d) None of the mentioned
c) 3 Any one of the 9 processes can get into critical section after executing P(mutex) which decrements the mutex value to 0. At this time P10 can enter critical section by incrementing the value to 1. Now any of the 9 processes can enter the critical section by again decrementing the mutex value to 0. None of the remaining processes can get into their critical sections.
A(n) ________ is the unit of work in a system A) mode bit B) timer C) process D) operating system
C) process
Which of the following statements is incorrect? A. An operating system provides an environment for the execution of the programs B. An operating system manages system resources C. Operating systems must provide both command line as well as graphical user interfaces D. Operating systems must provide both protection and security C. Operating systems may provide both command line as well as graphical user interfaces
C. Operating systems must provide both command line as well as graphical user interfaces
Which statement concerning privileged instructions is considered false? A. They may cause harm to the system B. They can only be executed in kernel mode C. They cannot be attempted from user mode D. They are used to manage interrupts
C. They cannot be attempted from user mode
The dining - philosophers problem will occur in case of : a) 5 philosophers and 5 chopsticks b) 4 philosophers and 5 chopsticks c) 3 philosophers and 5 chopsticks d) 6 philosophers and 5 chopsticks
a) 5 philosophers and 5 chopsticks
The growing phase is a phase in which : a) A transaction may obtain locks, but does not release any b) A transaction may obtain locks, and releases a few or all of them c) A transaction may release locks, but does not obtain any new locks d) A transaction may release locks, and does obtain new locks
a) A transaction may obtain locks, but does not release any
The following program consists of 3 concurrent processes and 3 binary semaphores. The semaphores are initialized as S0 = 1, S1 = 0, S2 = 0. Process P0 while(true) { wait(S0); print '0'; release(S1); release(S2); } Process P1 wait(S1); release(S0); Process P2 wait(S2); release(S0); How many times will P0 print '0' ? a) At least twice b) Exactly twice c) Exactly thrice d) Exactly once
a) At least twice
Which facility dynamically adds probes to a running system, both in user processes and in the kernel? a) DTrace b) DLocate c) DMap d) DAdd
a) DTrace
The objective of multiprogramming is to : a) Have some process running at all times b) Have multiple programs waiting in a queue ready to run c) To minimize CPU utilization d) None of the mentioned
a) Have some process running at all times
DMA is used for : a) High speed devices(disks and communications network) b) Low speed devices c) Utilizing CPU cycles d) All of the mentioned
a) High speed devices(disks and communications network)
When the process issues an I/O request : a) It is placed in an I/O queue b) It is placed in a waiting queue c) It is placed in the ready queue d) It is placed in the Job queue
a) It is placed in an I/O queue
When a process terminates : a) It is removed from all queues b) It is removed from all, but the job queue c) Its process control block is de-allocated d) Its process control block is never de-allocated
a) It is removed from all queues
What is a long-term scheduler ? a) It selects which process has to be brought into the ready queue b) It selects which process has to be executed next and allocates CPU c) It selects which process to remove from memory by swapping d) None of the mentioned
a) It selects which process has to be brought into the ready queue
The model in which one kernel thread is mapped to many user-level threads is called : a) Many to One model b) One to Many model c) Many to Many model d) One to One model
a) Many to One model
Cascading termination refers to termination of all child processes before the parent terminates ______ a) Normally b) Abnormally c) Normally or abnormally d) None of the mentioned
a) Normally
An edge from process Pi to Pj in a wait for graph indicates that : a) Pi is waiting for Pj to release a resource that Pi needs b) Pj is waiting for Pi to release a resource that Pj needs c) Pi is waiting for Pj to leave the system d) Pj is waiting for Pi to leave the system
a) Pi is waiting for Pj to release a resource that Pi needs
11. How does the Hardware trigger an interrupt ? a) Sending signals to CPU through system bus b) Executing a special program called interrupt program c) Executing a special program called system program d) Executing a special operation called system call
a) Sending signals to CPU through system bus
4. Consider the following set of processes, the length of the CPU burst time given in milliseconds : Process Burst time P1 6 P2 8 P3 7 P4 3 Assuming the above process being scheduled with the SJF scheduling algorithm : a) The waiting time for process P1 is 3ms b) The waiting time for process P1 is 0ms c) The waiting time for process P1 is 16ms d) The waiting time for process P1 is 9ms
a) The waiting time for process P1 is 3ms
When is the Many to One model at an advantage ? a) When the program does not need multithreading b) When the program has to be multi-threaded c) When there is a single processor d) None of the mentioned
a) When the program does not need multithreading
To enable a process to wait within the monitor, a) a condition variable must be declared as condition b) condition variables must be used as boolean objects c) semaphore must be used d) all of the mentioned
a) a condition variable must be declared as condition
All processes share a semaphore variable mutex, initialized to 1. Each process must execute wait(mutex) before entering the critical section and signal(mutex) afterward. Suppose a process executes in the following manner : wait(mutex); ..... critical section ..... wait(mutex); a) a deadlock will occur b) processes will starve to enter critical section c) several processes maybe executing in their critical section d) all of the mentioned
a) a deadlock will occur
In multilevel feedback scheduling algorithm a) a process can move to a different classified ready queue b) classification of ready queue is permanent c) processes are not classified into groups d) none of the mentioned
a) a process can move to a different classified ready queue
A monitor is characterized by : a) a set of programmer defined operators b) an identifier c) the number of variables in it d) all of the mentioned
a) a set of programmer defined operators
A deadlock can be broken by : a) abort one or more processes to break the circular wait b) abort all the process in the system c) preempt all resources from all processes d) none of the mentioned
a) abort one or more processes to break the circular wait
Bounded waiting implies that there exists a bound on the number of times a process is allowed to enter its critical section : a) after a process has made a request to enter its critical section and before the request is granted b) when another process is in its critical section c) before a process has made a request to enter its critical section d) none of the mentioned
a) after a process has made a request to enter its critical section and before the request is granted
The wait-for graph is a deadlock detection algorithm that is applicable when : a) all resources have a single instance b) all resources have multiple instances c) all resources have a single 7 multiple instance d) all of the mentioned
a) all resources have a single instance
Scheduling is : a) allowing a job to use the processor b) making proper use of processor c) all of the mentioned d) none of the mentioned
a) allowing a job to use the processor
Complex scheduling algorithms : a) are very appropriate for very large computers b) use minimal resources c) use many resources d) all of the mentioned
a) are very appropriate for very large computers Large computers are overloaded with greater number of processes
The portion of the process scheduler in an operating system that dispatches processes is concerned with : a) assigning ready processes to CPU b) assigning ready processes to waiting queue c) assigning running processes to blocked queue d) all of the mentioned
a) assigning ready processes to CPU
For Mutual exclusion to prevail in the system : a) at least one resource must be held in a non sharable mode b) the processor must be a uniprocessor rather than a multiprocessor c) there must be at least one resource in a sharable mode d) all of the mentioned
a) at least one resource must be held in a non sharable mode Explanation: If another process requests that resource (non - shareable resource), the requesting process must be delayed until the resource has been released.
Which one of the following is the deadlock avoidance algorithm? a) banker's algorithm b) round-robin algorithm c) elevator algorithm d) karn's algorithm
a) banker's algorithm
The child process can : a) be a duplicate of the parent process b) never be a duplicate of the parent process c) cannot have another program loaded into it d) never have another program loaded into it
a) be a duplicate of the parent process
An actual update is not allowed to a data item : a) before the corresponding log record is written out to stable storage b) after the corresponding log record is written out to stable storage c) until the whole log record has been checked for inconsistencies d) all of the mentioned
a) before the corresponding log record is written out to stable storage
The only state transition that is initiated by the user process itself is : a) block b) wakeup c) dispatch d) none of the mentioned
a) block
'm' processes share 'n' resources of the same type. The maximum need of each process doesn't exceed 'n' and the sum of all their maximum needs is always less than m+n. In this setup, deadlock : a) can never occur b) may occur c) has to occur d) none of the mentioned
a) can never occur
A system has 3 processes sharing 4 resources. If each process needs a maximum of 2 units then, deadlock : a) can never occur b) may occur c) has to occur d) none of the mentioned
a) can never occur
Message passing system allows processes to : a) communicate with one another without resorting to shared data b) communicate with one another by resorting to shared data c) share data d) name the recipient or sender of the message
a) communicate with one another without resorting to shared data
The link between two processes P and Q to send and receive messages is called : a) communication link b) message-passing link c) synchronization link d) all of the mentioned
a) communication link
Serializable schedules are ones where : a) concurrent execution of transactions is equivalent to the transactions executed serially b) the transactions can be carried out one after the other c) a valid result occurs after execution transactions d) none of the mentioned
a) concurrent execution of transactions is equivalent to the transactions executed serially
The jacketing technique is used to a) convert a blocking system call into non blocking system call b) create a new thread c) communicate between threads d) terminate a thread
a) convert a blocking system call into non blocking system call
Which process can be affected by other processes executing in the system? a) cooperating process b) child process c) parent process d) init process
a) cooperating process
A set of processes is deadlock if a) each process is blocked and will remain so forever b) each process is terminated c) all processes are trying to kill each other d) none of the mentioned
a) each process is blocked and will remain so forever
Which scheduling algorithm allocates the CPU first to the process that requests the CPU first? a) first-come, first-served scheduling b) shortest job scheduling c) priority scheduling d) none of the mentioned
a) first-come, first-served scheduling
In Unix, Which system call creates the new process? a) fork b) create c) new d) none of the mentioned
a) fork
Mutual exclusion implies that : a) if a process is executing in its critical section, then no other process must be executing in their critical sections b) if a process is executing in its critical section, then other processes must be executing in their critical sections c) if a process is executing in its critical section, then all the resources of the system must be blocked until it finishes execution d) none of the mentioned
a) if a process is executing in its critical section, then no other process must be executing in their critical sections
One way to ensure that the circular wait condition never holds is to : a) impose a total ordering of all resource types and to determine whether one precedes another in the ordering b) to never let a process acquire resources that are held by other processes c) to let a process wait for only one resource at a time d) all of the mentioned
a) impose a total ordering of all resource types and to determine whether one precedes another in the ordering
Scheduling is done so as to : a) increase CPU utilization b) decrease CPU utilization c) keep the CPU more idle d) None of the mentioned
a) increase CPU utilization
Scheduling is done so as to : a) increase the throughput b) decrease the throughput c) increase the duration of a specific amount of work d) None of the mentioned
a) increase the throughput
The One to One model allows : a) increased concurrency b) decreased concurrency c) increased or decreased concurrency d) concurrency equivalent to other models
a) increased concurrency
An interrupt vector a) is an address that is indexed to an interrupt handler b) is a unique device number that is indexed by an address c) is a unique identity given to an interrupt d) none of the mentioned
a) is an address that is indexed to an interrupt handler
A process having multiple threads of control implies : a) it can do more than one task at a time b) it can do only one task at a time, but much faster c) it has to use only one thread per process d) none of the mentioned
a) it can do more than one task at a time
If the semaphore value is negative : a) its magnitude is the number of processes waiting on that semaphore b) it is invalid c) no operation can be further performed on it until the signal operation is performed on it d) none of the mentioned
a) its magnitude is the number of processes waiting on that semaphore
The Banker's algorithm is _____________ than the resource allocation graph algorithm. a) less efficient b) more efficient c) equal d) none of the mentioned
a) less efficient
If a process fails, most operating system write the error information to a ______ a) log file b) another running process c) new file d) none of the mentioned
a) log file
For non sharable resources like a printer, mutual exclusion : a) must exist b) must not exist c) may exist d) none of the mentioned
a) must exist Explanation: A printer cannot be simultaneously shared by several processes
If a process is executing in its critical section, then no other processes can be executing in their critical section. This condition is called a) mutual exclusion b) critical exclusion c) synchronous exclusion d) asynchronous exclusion
a) mutual exclusion
The program follows to use a shared binary semaphore T : Process A int Y; A1: Y = X*2; A2: X = Y; signal(T); Process B int Z; B1: wait(T); B2: Z = X+1; X = Z; T is set to 0 before either process begins execution and, as before, X is set to 5. Now, how many different values of X are possible after both processes finish executing ? a) one b) two c) three d) four
a) one The semaphore T ensures that all the statements from A finish execution before B begins. So now there is only one way in which statements from A and B can be interleaved: A1 A2 B1 B2: X = 11.
The monitor construct ensures that : a) only one process can be active at a time within the monitor b) n number of processes can be active at a time within the monitor (n being greater than 1) c) the queue has only one process in it at a time d) all of the mentioned
a) only one process can be active at a time within the monitor
A single thread of control allows the process to perform: a) only one task at a time b) multiple tasks at a time c) only two tasks at a time c) all of the mentioned
a) only one task at a time
In the Many to One model, multiple threads are unable to run in parallel on multiprocessors because : a) only one thread can access the kernel at a time b) many user threads have access to just one kernel thread c) there is only one kernel thread d) none of the mentioned
a) only one thread can access the kernel at a time
When high priority task is indirectly preempted by medium priority task effectively inverting the relative priority of the two tasks, the scenario is called a) priority inversion b) priority removal c) priority exchange d) priority modification
a) priority inversion
Which one of the following is a visual ( mathematical ) way to determine the deadlock occurrence? a) resource allocation graph b) starvation graph c) inversion graph d) none of the mentioned
a) resource allocation graph
A deadlock avoidance algorithm dynamically examines the __________ to ensure that a circular wait condition can never exist. a) resource allocation state b) system storage state c) operating system d) resources
a) resource allocation state Resource allocation states are used to maintain the availability of the already and current available resources.
Each request requires that the system consider the _____________ to decide whether the current request can be satisfied or must wait to avoid a future possible deadlock. a) resources currently available b) processes that have previously been in the system c) resources currently allocated to each process d) future requests and releases of each process
a) resources currently available
RPC provides a(an) _____ on the client side, a separate one for each remote procedure. a) stub b) identifier c) name d) process identifier
a) stub
There are 10 different processes running on a workstation. Idle processes are waiting for an input event in the input queue. Busy processes are scheduled with the Round-Robin time sharing method. Which out of the following quantum times is the best value for small response times, if the processes have a short runtime, e.g. less than 10ms ? a) tQ = 15ms b) tQ = 40ms c) tQ = 45ms d) tQ = 50ms
a) tQ = 15ms
The register context and stacks of a thread are deallocated when the thread a) terminates b) blocks c) unblocks d) spawns
a) terminates
What is the reusable resource? a) that can be used by one process at a time and is not depleted by that use b) that can be used by more than one process at a time c) that can be shared between various threads d) none of the mentioned
a) that can be used by one process at a time and is not depleted by that use
A semaphore is a shared integer variable a) that can not drop below zero b) that can not be more than zero c) that can not drop below one d) that can not be more than one
a) that can not drop below zero
In a programmed input/output(PIO) : a) the CPU uses polling to watch the control bit constantly, looping to see if device is ready b) the CPU writes one data byte to the data register and sets a bit in control register to show that a byte is available c) the CPU receives an interrupt when the device is ready for the next byte d) the CPU runs a user written code and does accordingly
a) the CPU uses polling to watch the control bit constantly, looping to see if device is ready
In the Many to One model, if a thread makes a blocking system call : a) the entire process will be blocked b) a part of the process will stay blocked, with the rest running c) the entire process will run d) none of the mentioned
a) the entire process will be blocked
If a kernel thread performs a blocking system call, ____________ a) the kernel can schedule another thread in the application for execution b) the kernel cannot schedule another thread in the same application for execution c) the kernel must schedule another thread of a different application for execution d) the kernel must schedule another thread of the same application on a different processor
a) the kernel can schedule another thread in the application for execution
In the Many to Many model true concurrency cannot be gained because : a) the kernel can schedule only one thread at a time b) there are too many threads to handle c) it is hard to map threads with each other d) none of the mentioned
a) the kernel can schedule only one thread at a time
An SJF algorithm is simply a priority algorithm where the priority is : a) the predicted next CPU burst b) the inverse of the predicted next CPU burst c) the current CPU burst d) anything the user wants
a) the predicted next CPU burst The larger the CPU burst, the lower the priority.
Every time a request for allocation cannot be granted immediately, the detection algorithm is invoked. This will help identify : a) the set of processes that have been deadlocked b) the set of processes in the deadlock queue c) the specific process that caused the deadlock d) all of the mentioned
a) the set of processes that have been deadlocked
A system is in the safe state if a) the system can allocate resources to each process in some order and still avoid a deadlock b) there exist a safe sequence c) all of the mentioned d) none of the mentioned
a) the system can allocate resources to each process in some order and still avoid a deadlock
To avoid deadlock a) there must be a fixed number of resources to allocate b) resource allocation must be done only once c) all deadlocked processes must be aborted d) inversion technique can be used
a) there must be a fixed number of resources to allocate
When the event for which a thread is blocked occurs, a) thread moves to the ready queue b) thread remains blocked c) thread completes d) a new thread is provided
a) thread moves to the ready queue
With multiprogramming, ______ is used productively. a) time b) space c) money d) all of the mentioned
a) time
Deadlock prevention is a set of methods : a) to ensure that at least one of the necessary conditions cannot hold b) to ensure that all of the necessary conditions do not hold c) to decide if the requested resources for a process have to be given or not d) to recover from a deadlock
a) to ensure that at least one of the necessary conditions cannot hold
The main function of the command interpreter is a) to get and execute the next user-specified command b) to provide the interface between the API and application program c) to handle the files in operating system d) none of the mentioned
a) to get and execute the next user-specified command
A collection of instructions that performs a single logical function is called : a) transaction b) operation c) function d) all of the mentioned
a) transaction
With round robin scheduling algorithm in a time shared system, a) using very large time slices converts it into First come First served scheduling algorithm b) using very small time slices converts it into First come First served scheduling algorithm c) using extremely small time slices increases performance d) using very small time slices converts it into Shortest Job First algorithm
a) using very large time slices converts it into First come First served scheduling algorithm
A parent process calling _____ system call will be suspended until children processes terminate. a) wait b) fork c) exit d) exec
a) wait
The two atomic operations permissible on semaphores are : a) wait b) stop c) hold d) none of the mentioned
a) wait
Which system call returns the process identifier of a terminated child? a) wait b) exit c) fork d) get
a) wait
The operations that can be invoked on a condition variable are : a) wait & signal b) hold & wait c) signal & hold d) continue & signal
a) wait & signal
What is the ready state of a process? a) when process is scheduled to run after some execution b) when process is unable to run until some task has been completed c) when process is using the CPU d) none of the mentioned
a) when process is scheduled to run after some execution
The resource allocation graph is not applicable to a resource allocation system : a) with multiple instances of each resource type b) with a single instance of each resource type c) single & multiple instance of each resource type d) none of the mentioned
a) with multiple instances of each resource type
CPU scheduling is the basis of ___________ a) multiprocessor systems b) multiprogramming operating systems c) larger memory sized systems d) none of the mentioned
b) multiprogramming operating systems
At a particular time of computation the value of a counting semaphore is 7.Then 20 P operations and 15 V operations were completed on this semaphore.The resulting value of the semaphore is : (GATE 1987) a) 42 b) 2 c) 7 d) 12
b) 2 P represents Wait and V represents Signal. P operation will decrease the value by 1 every time and V operation will increase the value by 1 every time.
Which of the following are TRUE for direct communication : a) A communication link can be associated with N number of process(N = max. number of processes supported by system) b) A communication link can be associated with exactly two processes c) Exactly N/2 links exist between each pair of processes(N = max. number of processes supported by system) d) Exactly two link exists between each pair of processes
b) A communication link can be associated with exactly two processes
For a Hold and wait condition to prevail : a) A process must be not be holding a resource, but waiting for one to be freed, and then request to acquire it b) A process must be holding at least one resource and waiting to acquire additional resources that are being held by other processes c) A process must hold at least one resource and not be waiting to acquire additional resources d) None of the mentioned
b) A process must be holding at least one resource and waiting to acquire additional resources that are being held by other processes
Bounded capacity and Unbounded capacity queues are referred to as : a) Programmed buffering b) Automatic buffering c) User defined buffering d) No buffering
b) Automatic buffering
Spinlocks are intended to provide __________ only. a) Mutual Exclusion b) Bounded Waiting c) Aging d) Progress
b) Bounded Waiting
The two steps of a process execution are : a) I/O & OS Burst b) CPU & I/O Burst c) Memory & I/O Burst d) OS & Memory Burst
b) CPU & I/O Burst
The Process Control Block is: a) Process type variable b) Data Structure c) A secondary storage section d) A Block in memory
b) Data Structure
What will happen if a non-recursive mutex is locked more than once ? a) Starvation b) Deadlock c) Aging d) Signaling
b) Deadlock If a thread which had already locked a mutex, tries to lock the mutex again, it will enter into the waiting list of that mutex, which results in deadlock. It is because no other thread can unlock the mutex.
How does the software trigger an interrupt ? a) Sending signals to CPU through bus b) Executing a special operation called system call c) Executing a special program called system program d) Executing a special program called interrupt trigger program
b) Executing a special operation called system call
In the layered approach of Operating Systems : a) Bottom Layer(0) is the User interface b) Highest Layer(N) is the User interface c) Bottom Layer(N) is the hardware d) Highest Layer(N) is the hardware
b) Highest Layer(N) is the User interface
Which of the following concurrency control protocols ensure both conflict serializability and freedom from deadlock ? I) 2-phase locking II) Timestamp ordering a) I only b) II only c) Both I and II d) Neither I nor II
b) II only
Semaphores are mostly used to implement : a) System calls b) IPC mechanisms c) System protection d) None of the mentioned
b) IPC mechanisms
What is a short-term scheduler ? a) It selects which process has to be brought into the ready queue b) It selects which process has to be executed next and allocates CPU c) It selects which process to remove from memory by swapping d) None of the mentioned
b) It selects which process has to be executed next and allocates CPU
The disadvantage of a process being allocated all its resources before beginning its execution is : a) Low CPU utilization b) Low resource utilization c) Very high resource utilization d) None of the mentioned
b) Low resource utilization
Which of the following is not the state of a process? a) New b) Old c) Waiting d) Running
b) Old
The model in which one user-level thread is mapped to many kernel level threads is called : a) Many to One model b) One to Many model c) Many to Many model d) One to One model
b) One to Many model
Which of the following do not belong to queues for processes ? a) Job Queue b) PCB queue c) Device Queue d) Ready Queue
b) PCB queue
Round robin scheduling falls under the category of : a) Non preemptive scheduling b) Preemptive scheduling c) All of the mentioned d) None of the mentioned
b) Preemptive scheduling
The strategy of making processes that are logically runnable to be temporarily suspended is called : a) Non preemptive scheduling b) Preemptive scheduling c) Shortest job first d) First come First served
b) Preemptive scheduling
The address of the next instruction to be executed by the current process is provided by the a) CPU registers b) Program counter c) Process stack d) Pipe
b) Program counter
In a time-sharing operating system, when the time slot given to a process is completed, the process goes from the running state to the : a) Blocked state b) Ready state c) Suspended state d) Terminated state
b) Ready state
The most optimal scheduling algorithm is : a) FCFS - First come First served b) SJF - Shortest Job First c) RR - Round Robin d) None of the mentioned
b) SJF - Shortest Job First
Under multiprogramming, turnaround time for short jobs is usually ________ and that for long jobs is slightly ___________ a) Lengthened; Shortened b) Shortened; Lengthened c) Shortened; Shortened d) Shortened; Unchanged
b) Shortened; Lengthened
Which of the following algorithms tends to minimize the process flow time ? a) First come First served b) Shortest Job First c) Earliest Deadline First d) Longest Job First
b) Shortest Job First
Which of the following need not necessarily be saved on a context switch between processes ? a) General purpose registers b) Translation lookaside buffer c) Program counter d) All of the mentioned
b) Translation lookaside buffer
In the following cases non - preemptive scheduling occurs : a) When a process switches from the running state to the ready state b) When a process goes from the running state to the waiting state c) When a process switches from the waiting state to the ready state d) All of the mentioned
b) When a process goes from the running state to the waiting state
The child process completes execution,but the parent keeps executing, then the child process is known as : a) Orphan b) Zombie c) Body d) Dead
b) Zombie
A system with 5 processes P0 through P4 and three resource types A, B, C has A with 10 instances, B with 5 instances, and C with 7 instances. At time t0, the following snapshot has been taken Process P0 P1 P2 P3 P4 Allocation (process-wise : P0 through P4 top TO bottom) A B C 0 1 0 2 0 0 3 0 2 2 1 1 0 0 2 MAX (process-wise : P0 through P4 top TO bottom) A B C 7 5 3 3 2 2 9 0 2 2 2 2 4 3 3 Available A B C 3 3 2 The sequence <P1, P3, P4, P2, P0> leads the system to : a) an unsafe state b) a safe state c) a protected state d) a deadlock
b) a safe state
The remote method invocation : a) allows a process to invoke memory on a remote object b) allows a thread to invoke a method on a remote object c) allows a thread to invoke memory on a remote object d) allows a process to invoke a method on a remote object
b) allows a thread to invoke a method on a remote object
Inter process communication : a) allows processes to communicate and synchronize their actions when using the same address space b) allows processes to communicate and synchronize their actions without using the same address space c) allows the processes to only synchronize their actions without communication d) none of the mentioned
b) allows processes to communicate and synchronize their actions without using the same address space
The wait operation of the semaphore basically works on the basic _______ system call. a) stop() b) block() c) hold() d) wait()
b) block()
In priority scheduling algorithm, when a process arrives at the ready queue, its priority is compared with the priority of a) all process b) currently running process c) parent process d) init process
b) currently running process
Scheduling is done so as to : a) increase the turnaround time b) decrease the turnaround time c) keep the turnaround time same d) there is no relation between scheduling and turnaround time
b) decrease the turnaround time
A deadlock free solution to the dining philosophers problem : a) necessarily eliminates the possibility of starvation b) does not necessarily eliminate the possibility of starvation c) eliminates any possibility of any kind of problem further d) none of the mentioned
b) does not necessarily eliminate the possibility of starvation
A deadlock eventually cripples system throughput and will cause the CPU utilization to ______ a) increase b) drop c) stay still d) none of the mentioned
b) drop
In the bakery algorithm to solve the critical section problem : a) each process is put into a queue and picked up in an ordered manner b) each process receives a number (may or may not be unique) and the one with the lowest number is served next c) each process gets a unique number and the one with the highest number is served next d) each process gets a unique number and the one with the lowest number is served next
b) each process receives a number (may or may not be unique) and the one with the lowest number is served next
The FIFO algorithm : a) first executes the job that came in last in the queue b) first executes the job that came in first in the queue c) first executes the job that needs minimal processor d) first executes the job that has maximum processor needs
b) first executes the job that came in first in the queue
If deadlocks occur frequently, the detection algorithm must be invoked ________ a) rarely b) frequently c) rarely & frequently c) none of the mentioned
b) frequently
A clustered system______. a) is an operating system that provides file sharing across a network. b) gathers together multiple CPUs to accomplish computational work. c) is used when rigid time requirements are present d) can only operate one application at a time e) can only run on a uniprocessor system
b) gathers together multiple CPUs to accomplish computational work.
A heavy weight process : a) has multiple threads of execution b) has a single thread of execution c) can have multiple or a single thread for execution d) none of the mentioned
b) has a single thread of execution
The OS X has ____________ a) monolithic kernel b) hybrid kernel c) microkernel d) monolithic kernel with modules
b) hybrid kernel
Multithreading on a multi - CPU machine : a) decreases concurrency b) increases concurrency c) doesn't affect the concurrency d) can increase or decrease the concurrency
b) increases concurrency
Those processes should be aborted on occurrence of a deadlock, the termination of which : a) is more time consuming b) incurs minimum cost c) safety is not hampered d) all of the mentioned
b) incurs minimum cost
For sharable resources, mutual exclusion : a) is required b) is not required c) may be or may not be required c) none of the mentioned
b) is not required They do not require mutually exclusive access, and hence cannot be involved in a deadlock
The Zero Capacity queue : a) is referred to as a message system with buffering b) is referred to as a message system with no buffering c) is referred to as a link d) none of the mentioned
b) is referred to as a message system with no buffering
Because the kernel thread management is done by the Operating System itself : a) kernel threads are faster to create than user threads b) kernel threads are slower to create than user threads c) kernel threads are easier to manage as well as create then user threads d) none of the mentioned
b) kernel threads are slower to create than user threads
The real difficulty with SJF in short term scheduling is : a) it is too good an algorithm b) knowing the length of the next CPU request c) it is too complex to understand d) none of the mentioned
b) knowing the length of the next CPU request
The time required to create a new thread in an existing process is a) greater than the time required to create a new process b) less than the time required to create a new process c) equal to the time required to create a new process d) none of the mentioned
b) less than the time required to create a new process
Multithreaded programs are : a) lesser prone to deadlocks b) more prone to deadlocks c) not at all prone to deadlocks d) none of the mentioned
b) more prone to deadlocks Explanation: Multiple threads can compete for shared resources.
The FCFS algorithm is particularly troublesome for ____________ a) time sharing systems b) multiprogramming systems c) multiprocessor systems d) operating systems
b) multiprogramming systems In a time sharing system, each user needs to get a share of the CPU at regular intervals.
A mutex : a) is a binary mutex b) must be accessed from only one process c) can be accessed from multiple processes d) None of the mentioned
b) must be accessed from only one process
All unsafe states are : a) deadlocks b) not deadlocks c) fatal d) none of the mentioned
b) not deadlocks
In the Many to Many model when a thread performs a blocking system call : a) other threads are strictly prohibited from running b) other threads are allowed to run c) other threads only from other processes are allowed to run d) none of the mentioned
b) other threads are allowed to run
In the One to One model when a thread makes a blocking system call : a) other threads are strictly prohibited from running b) other threads are allowed to run c) other threads only from other processes are allowed to run d) none of the mentioned
b) other threads are allowed to run
If one thread opens a file with read privileges then a) other threads in the another process can also read from that file b) other threads in the same process can also read from that file c) any other thread can not read from that file d) all of the mentioned
b) other threads in the same process can also read from that file
Which one of the following is not a valid state of a thread? a) running b) parsing c) ready d) blocked
b) parsing
A situation where several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which access takes place is called : a) data consistency b) race condition c) aging d) starvation
b) race condition
When several processes access the same data concurrently and the outcome of the execution depends on the particular order in which the access takes place, is called a) dynamic condition b) race condition c) essential condition d) critical condition
b) race condition
Time quantum is defined in a) shortest job scheduling algorithm b) round robin scheduling algorithm c) priority scheduling algorithm d) multilevel queue scheduling algorithm
b) round robin scheduling algorithm
What is a trap/exception ? a) hardware generated interrupt caused by an error b) software generated interrupt caused by an error c) user generated interrupt caused by an error d) none of the mentioned
b) software generated interrupt caused by an error
A problem encountered in multitasking when a process is perpetually denied necessary resources is called a) deadlock b) starvation c) inversion d) aging
b) starvation
In a memory mapped input/output : a) the CPU uses polling to watch the control bit constantly, looping to see if device is ready b) the CPU writes one data byte to the data register and sets a bit in control register to show that a byte is available c) the CPU receives an interrupt when the device is ready for the next byte d) the CPU runs a user written code and does accordingly
b) the CPU writes one data byte to the data register and sets a bit in control register to show that a byte is available
In the Zero capacity queue : a) the queue can store at least one message b) the sender blocks until the receiver receives the message c) the sender keeps sending and the messages don't wait in the queue d) none of the mentioned
b) the sender blocks until the receiver receives the message
In the non blocking send : a) the sending process keeps sending until the message is received b) the sending process sends the message and resumes operation c) the sending process keeps sending until it receives a message d) none of the mentioned
b) the sending process sends the message and resumes operation
A state is safe, if : a) the system does not crash due to deadlock occurrence b) the system can allocate resources to each process in some order and still avoid a deadlock c) the state keeps the system protected and safe d) all of the mentioned
b) the system can allocate resources to each process in some order and still avoid a deadlock
Waiting time is : a) the total time in the blocked and waiting queues b) the total time spent in the ready queue c) the total time spent in the running queue d) the total time from the completion till the submission of a process
b) the total time spent in the ready queue
Response time is : a) the total time taken from the submission time till the completion time b) the total time taken from the submission time till the first response is produced c) the total time taken from submission time till the response is output d) none of the mentioned
b) the total time taken from the submission time till the first response is produced
If the wait for graph contains a cycle : a) then a deadlock does not exist b) then a deadlock exists c) then the system is in a safe state d) either deadlock exists or system is in a safe state
b) then a deadlock exists
If no cycle exists in the resource allocation graph : a) then the system will not be in a safe state b) then the system will be in a safe state c) all of the mentioned d) none of the mentioned
b) then the system will be in a safe state
In the bounded buffer problem : a) there is only one buffer b) there are n buffers ( n being greater than one but finite) c) there are infinite buffers d) the buffer size is bounded
b) there are n buffers ( n being greater than one but finite)
The main disadvantage of spinlocks is that : a) they are not sufficient for many process b) they require busy waiting c) they are unreliable sometimes d) they are too complex for programmers
b) they require busy waiting
A process can be a) single threaded b) multithreaded c) both single threaded and multithreaded d) none of the mentioned
c) both single threaded and multithreaded
The acronym SMP stands for a.same many programs b.symmetric multiprocessing c.simple multiple protocols d.svitaks many programs e.silly multiple pranks
b.symmetric multiprocessing
The shrinking phase is a phase in which : a) A transaction may obtain locks, but does not release any b) A transaction may obtain locks, and releases a few or all of them c) A transaction may release locks, but does not obtain any new locks d) A transaction may release locks, and does obtain new locks
c) A transaction may release locks, but does not obtain any new locks
The two ways of aborting processes and eliminating deadlocks are : a) Abort all deadlocked processes b) Abort all processes c) Abort one process at a time until the deadlock cycle is eliminated d) All of the mentioned
c) Abort one process at a time until the deadlock cycle is eliminated
Cost factors of process termination include : a) Number of resources the deadlock process is not holding b) CPU utilization at the time of deadlock c) Amount of time a deadlocked process has thus far consumed during its execution d) All of the mentioned
c) Amount of time a deadlocked process has thus far consumed during its execution
What is an ISR ? a) Information Service Request b) Interrupt Service Request c) Interrupt Service Routine d) Information Service Routine
c) Interrupt Service Routine
What is a medium-term scheduler ? a) It selects which process has to be brought into the ready queue b) It selects which process has to be executed next and allocates CPU c) It selects which process to remove from memory by swapping d) None of the mentioned
c) It selects which process to remove from memory by swapping
The content of the matrix Need is : a) Allocation - Available b) Max - Available c) Max - Allocation d) Allocation - Max
c) Max - Allocation
To differentiate the many network services a system supports ______ are used. a) Variables b) Sockets c) Ports d) Service names
c) Ports
In UNIX, each process is identified by its : a) Process Control Block b) Device Queue c) Process Identifier d) None of the the mentioned
c) Process Identifier
The entry of all the PCBs of the current processes is in: a) Process Register b) Program Counter c) Process Table d) Process Unit
c) Process Table
The bounded buffer problem is also known as : a) Readers - Writers problem b) Dining - Philosophers problem c) Producer - Consumer problem d) None of the mentioned
c) Producer - Consumer problem
A process that is based on IPC mechanism which executes on different systems and can communicate with other processes using message based communication, is called ________ a) Local Procedure Call b) Inter Process Communication c) Remote Procedure Call d) Remote Machine Invocation
c) Remote Procedure Call
Which of the following does not interrupt a running process ? a) A device b) Timer c) Scheduler process d) Power failure
c) Scheduler process
The primary distinction between the short term scheduler and the long term scheduler is : a) The length of their queues b) The type of processes they schedule c) The frequency of their execution d) None of the mentioned
c) The frequency of their execution
The TestAndSet instruction is executed : a) after a particular process b) periodically c) atomically d) none of the mentioned
c) atomically
Process synchronization can be done on a) hardware level b) software level c) both hardware and software level d) none of the mentioned
c) both hardware and software level
Mutual exclusion can be provided by the a) mutex locks b) binary semaphores c) both mutex locks and binary semaphores d) none of the mentioned
c) both mutex locks and binary semaphores
Which one of the following is not shared by threads? a) program counter b) stack c) both program counter and stack d) none of the mentioned
c) both program counter and stack
By operating system, the resource management can be done via a) time division multiplexing b) space division multiplexing c) both time and space division multiplexing d) none of the mentioned
c) both time and space division multiplexing
A semaphore : a) is a binary mutex b) must be accessed from only one process c) can be accessed from multiple processes d) none of the mentioned
c) can be accessed from multiple processes
Messages sent by a process : a) have to be of a fixed size b) have to be a variable size c) can be fixed or variable sized d) None of the mentioned
c) can be fixed or variable sized
If the kernel is single threaded, then any user level thread performing a blocking system call will : a) cause the entire process to run along with the other threads b) cause the thread to block with the other threads running c) cause the entire process to block even if the other threads are available to run d) none of the mentioned
c) cause the entire process to block even if the other threads are available to run
A terminated transaction that has completed its execution successfully is ____________ otherwise it is __________ a) committed, destroyed b) aborted, destroyed c) committed, aborted d) none of the mentioned
c) committed, aborted
The disadvantage of invoking the detection algorithm for every request is : a) overhead of the detection algorithm due to consumption of memory b) excessive time consumed in the request to be allocated memory c) considerable overhead in computation time d) all of the mentioned
c) considerable overhead in computation time
The code that changes the value of the semaphore is a) remainder section code b) non - critical section code c) critical section code d) none of the mentioned
c) critical section code
Concurrent access to shared data may result in a) data consistency b) data insecurity c) data inconsistency d) none of the mentioned
c) data inconsistency
Scheduling is done so as to : a) increase the waiting time b) keep the waiting time the same c) decrease the waiting time d) none of the mentioned
c) decrease the waiting time
If all processes I/O bound, the ready queue will almost always be ______ and the Short term Scheduler will have a ______ to do. a) full,little b) full,lot c) empty,little d) empty,lot
c) empty,little
For effective operating system, when to check for deadlock? a) every time a resource request is made b) at fixed time intervals c) every time a resource request is made at fixed time intervals d) none of the mentioned
c) every time a resource request is made at fixed time intervals
Orders are processed in the sequence they arrive if _______ rule sequences the jobs. a) earliest due date b) slack time remaining c) first come, first served d) critical ratio
c) first come, first served
Remote Procedure Calls are used : a) for communication between two processes remotely different from each other on the same system b) for communication between two processes on the same system c) for communication between two processes on separate systems d) None of the mentioned
c) for communication between two processes on separate systems
The following pair of processes share a common variable X : Process A int Y; A1: Y = X*2; A2: X = Y; Process B int Z; B1: Z = X+1; B2: X = Z; X is set to 5 before either process begins execution. As usual, statements within a process are executed sequentially, but statements in process A may execute in any order with respect to statements in process B. How many different values of X are possible after both processes finish executing ? a) two b) three c) four d) eight
c) four Here are the possible ways in which statements from A and B can be interleaved. A1 A2 B1 B2: X = 11 A1 B1 A2 B2: X = 6 A1 B1 B2 A2: X = 10 B1 A1 B2 A2: X = 10 B1 A1 A2 B2: X = 6 B1 B2 A1 A2: X = 12.
A locking protocol is one that : a) governs how locks are acquired b) governs how locks are released c) governs how locks are acquired and released d) none of the mentioned
c) governs how locks are acquired and released
A monitor is a type of : a) semaphore b) low level synchronization construct c) high level synchronization construct d) none of the mentioned
c) high level synchronization construct
Semaphore is a/an _______ to solve the critical section problem. a) hardware for a system b) special program for a system c) integer variable d) none of the mentioned
c) integer variable
One of the disadvantages of the priority scheduling algorithm is that : a) it schedules in a very complex manner b) its scheduling takes up a lot of time c) it can lead to some low priority process waiting indefinitely for the CPU d) none of the mentioned
c) it can lead to some low priority process waiting indefinitely for the CPU
Which one of the following is not true? a) kernel is the program that constitutes the central core of the operating system b) kernel is the first part of operating system to load into memory during booting c) kernel is made of various modules which can not be loaded in running operating system d) kernel remains in the memory during the entire computer session
c) kernel is made of various modules which can not be loaded in running operating system
To resolve the problem of data representation on different systems RPCs define _____________ a) machine dependent representation of data b) machine representation of data c) machine-independent representation of data
c) machine-independent representation of data
To resolve the problem of data representation on different systems RPCs define _____________ a) machine dependent representation of data b) machine representation of data c) machine-independent representation of data d) none of the mentioned
c) machine-independent representation of data
An I/O bound program will typically have : a) a few very short CPU bursts b) many very short I/O bursts c) many very short CPU bursts d) a few very short I/O bursts
c) many very short CPU bursts
Given a priori information about the ________ number of resources of each type that maybe requested for each process, it is possible to construct an algorithm that ensures that the system will never enter a deadlock state. a) minimum b) average c) maximum d) approximate
c) maximum
In a multiprogramming environment : a) the processor executes more than one process at a time b) the programs are developed by more than one person c) more than one process resides in the memory d) a single user can execute many programs at the same time
c) more than one process resides in the memory
The number of resources requested by a process : a) must always be less than the total number of resources available in the system b) must always be equal to the total number of resources available in the system c) must not exceed the total number of resources available in the system d) must exceed the total number of resources available in the system
c) must not exceed the total number of resources available in the system
Restricting the child process to a subset of the parent's resources prevents any process from : a) overloading the system by using a lot of secondary storage b) under-loading the system by very less CPU utilization c) overloading the system by creating a lot of sub-processes d) crashing the system by utilizing multiple resources
c) overloading the system by creating a lot of sub-processes
All processes share a semaphore variable mutex, initialized to 1. Each process must execute wait(mutex) before entering the critical section and signal(mutex) afterward. Suppose a process executes in the following manner : signal(mutex); ..... critical section ..... wait(mutex); In this situation : a) a deadlock will occur b) processes will starve to enter critical section c) several processes maybe executing in their critical section d) all of the mentioned
c) several processes maybe executing in their critical section
In an interrupt driven input/output : a) the CPU uses polling to watch the control bit constantly, looping to see if device is ready b) the CPU writes one data byte to the data register and sets a bit in control register to show that a byte is available c) the CPU receives an interrupt when the device is ready for the next byte d) the CPU runs a user written code and does accordingly
c) the CPU receives an interrupt when the device is ready for the next byte
Dispatch latency is : a) the speed of dispatching a process from running to the ready state b) the time of dispatching a process from running to ready state and keeping the CPU idle c) the time to stop one process and start running another one d) none of the mentioned
c) the time to stop one process and start running another one
In indirect communication between processes P and Q : a) there is another process R to handle and pass on the messages between P and Q b) there is another machine between the two processes to help communication c) there is a mailbox to help communication between P and Q d) none of the mentioned
c) there is a mailbox to help communication between P and Q
A solution to the problem of indefinite blockage of low - priority processes is : a) Starvation b) Wait queue c) Ready queue d) Aging
d) Aging
12. Which operation is performed by an interrupt handler ? a) Saving the current state of the system b) Loading the interrupt handling code and executing it c) Once done handling, bringing back the system to the original state it was before the interrupt occurred d) All of the mentioned
d) All of the mentioned
For a deadlock to arise, which of the following conditions must hold simultaneously ? a) Mutual exclusion b) No preemption c) Hold and wait d) All of the mentioned
d) All of the mentioned
Spinlocks are : a) CPU cycles wasting locks over critical sections of programs b) Locks that avoid time wastage in context switches c) Locks that work better on multiprocessor systems d) All of the mentioned
d) All of the mentioned
The data structures available in the Banker's algorithm are : a) Available b) Need c) Allocation d) All of the mentioned
d) All of the mentioned
9. Consider the methods used by processes P1 and P2 for accessing their critical sections whenever needed, as given below. The initial values of shared boolean variables S1 and S2 are randomly assigned. (GATE 2010) Method used by P1 : while(S1==S2); Critical section S1 = S2; Method used by P2 : while(S1!=S2); Critical section S2 = not(S1); Which of the following statements describes properties achieved ? a) Mutual exclusion but not progress b) Progress but not mutual exclusion c) Neither mutual exclusion nor progress d) Both mutual exclusion and progress
d) Both mutual exclusion and progress
Embedded computers typically run on a ____ OS a) Windows XP b) Network c) Real-time d) Clustered e) Non-clustered
d) Clustered
A message passing model is ___. a) Faster than shared memory model b) A network protocol, and does not apply to operating systems c) only useful for small OS d) Easier to implement than shared memory model for intercomputer communication e) Only useful for large complex operating systems
d) Easier to implement than shared memory model for intercomputer communication
Which of the following statements are true ? (GATE 2010) I. Shortest remaining time first scheduling may cause starvation II. Preemptive scheduling may cause starvation III. Round robin is better than FCFS in terms of response time a) I only b) I and III only c) II and III only d) I, II and III
d) I, II and III I) Shortest remaining time first scheduling is a preemptive version of shortest job scheduling. It may cause starvation as shorter processes may keep coming and a long CPU burst process never gets CPU. II) Preemption may cause starvation. If priority based scheduling with preemption is used, then a low priority process may never get CPU. III) Round Robin Scheduling improves response time as all processes get CPU after a specified time.
Two processes, P1 and P2, need to access a critical section of code. Consider the following synchronization construct used by the processes : Process P1 : while(true) { w1 = true; while(w2 == true); Critical section w1 = false; } Remainder Section Process P2 : while(true) { w2 = true; while(w1 == true); Critical section w2 = false; } Remainder Section Here, w1 and w2 are shared variables, which are initialized to false. Which one of the following statements is TRUE about the above construct? a) It does not ensure mutual exclusion b) It does not ensure bounded waiting c) It requires that processes enter the critical section in strict alternation d) It does not prevent deadlocks, but ensures mutual exclusion
d) It does not prevent deadlocks, but ensures mutual exclusion
A system has 12 magnetic tape drives and 3 processes : P0, P1, and P2. Process P0 requires 10 tape drives, P1 requires 4 and P2 requires 9 tape drives Process P0 P1 P2 Maximum needs (process-wise : P0 through P2 top to bottom) 10 4 9 Currently allocated (process-wise) 5 2 2 Which of the following sequence is a safe sequence ? a) P0, P1, P2 b) P1, P2, P0 c) P2, P0, P1 d) P1, P0, P2
d) P1, P0, P2
A process stack does not contain a) Function parameters b) Local variables c) Return addresses d) PID of child process
d) PID of child process
Which one of the following is not a real time operating system? a) VxWorks b) Windows CE c) RTLinux d) Palm OS
d) Palm OS
The full form of RMI : a) Remote Memory Installation b) Remote Memory Invocation c) Remote Method Installation d) Remote Method Invocation
d) Remote Method Invocation
Preemptive Shortest Job First scheduling is sometimes called : a) Fast SJF scheduling b) EDF scheduling - Earliest Deadline First c) HRRN scheduling - Highest Response Ratio Next d) SRTN scheduling - Shortest Remaining Time Next
d) SRTN scheduling - Shortest Remaining Time Next
With _____________ only one process can execute at a time; meanwhile all other process are waiting for the processor. With ______________ more than one process can be running simultaneously each on a different processor. a) Multiprocessing, Multiprogramming b) Multiprogramming, Uniprocessing c) Multiprogramming, Multiprocessing d) Uniprogramming, Multiprocessing
d) Uniprogramming, Multiprocessing
In the write ahead logging a _____ is maintained. a) a memory b) a system c) a disk d) a log record
d) a log record
A monitor is a module that encapsulates a) shared data structures b) procedures that operate on shared data structure c) synchronization between concurrent procedure invocation d) all of the mentioned
d) all of the mentioned
A process can be terminated due to a) normal exit b) fatal error c) killed by another process d) all of the mentioned
d) all of the mentioned
In operating system, each process has its own a) address space and global variables b) open files c) pending alarms, signals and signal handlers d) all of the mentioned
d) all of the mentioned
Resource sharing helps : a) share the memory and resources of the process to which the threads belong b) an application have several different threads of activity all within the same address space c) reduce the address space that a process could potentially use d) all of the mentioned
d) all of the mentioned
The process to be aborted is chosen on the basis of the following factors : a) priority of the process b) process is interactive or batch c) how long the process has computed d) all of the mentioned
d) all of the mentioned
The stub : a) transmits the message to the server where the server side stub receives the message and invokes procedure on the server side b) packs the parameters into a form transmittable over the network c) locates the port on the server d) all of the mentioned
d) all of the mentioned
The switching of the CPU from one process or thread to another is called : a) process switch b) task switch c) context switch d) all of the mentioned
d) all of the mentioned
The system periodically performs checkpoints that consists of the following operation(s) : a) Putting all the log records currently in main memory onto stable storage b) putting all modified data residing in main memory onto stable storage c) putting a log record onto stable storage d) all of the mentioned
d) all of the mentioned
Thread synchronization is required because a) all threads of a process share the same address space b) all threads of a process share the same global variables c) all threads of a process can share the same files d) all of the mentioned
d) all of the mentioned
What is operating system? a) collection of programs that manages hardware resources b) system service provider to the application programs c) link to interface the hardware and application programs d) all of the mentioned
d) all of the mentioned
What is the drawback of banker's algorithm? a) in advance processes rarely know that how much resource they will need b) the number of processes changes as time progresses c) resource once available can disappear d) all of the mentioned
d) all of the mentioned
Which of the following condition is required for deadlock to be possible? a) mutual exclusion b) a process may hold allocated resources while awaiting assignment of other resources c) no resource can be forcibly removed from a process holding it d) all of the mentioned
d) all of the mentioned
Which one of the following error will be handle by the operating system? a) power failure b) lack of paper in printer c) connection failure in the network d) all of the mentioned
d) all of the mentioned
Write ahead logging is a way : a) to ensure atomicity b) to keep data consistent c) that records data on stable storage d) all of the mentioned
d) all of the mentioned
To ensure that the hold and wait condition never occurs in the system, it must be ensured that : a) whenever a resource is requested by a process, it is not holding any other resources b) each process must request and be allocated all its resources before it begins its execution c) a process can request resources only when it has none d) all of the mentioned
d) all of the mentioned Explanation: c - A process may request some resources and use them. Before it can can request any additional resources, however it must release all the resources that it is currently allocated
The initial program that is run when the computer is powered up is called : a) boot program b) bootloader c) initializer d) bootstrap program
d) bootstrap program
The context of a process in the PCB of a process does not contain : a) the value of the CPU registers b) the process state c) memory-management information d) context switch time
d) context switch time
Which of the following is the drawback of the One to One Model ? a) increased concurrency provided by this model b) decreased concurrency provided by this model c) creating so many threads at once can crash the system d) creating a user thread requires creating the corresponding kernel thread
d) creating a user thread requires creating the corresponding kernel thread
Which of the following statements are true ? (GATE 2010) i) Shortest remaining time first scheduling may cause starvation ii) Preemptive scheduling may cause starvation iii) Round robin is better than FCFS in terms of response time a) i only b) i and iii only c) ii and iii only d) i, ii and iii
d) i, ii and iii
'Aging' is : a) keeping track of cache contents b) keeping track of what pages are currently residing in memory c) keeping track of how many times a given page is referenced d) increasing the priority of jobs to ensure termination in a finite time
d) increasing the priority of jobs to ensure termination in a finite time
A procedure defined within a ________ can access only those variables declared locally within the _______ and its formal parameters. a) process, semaphore b) process, monitor c) semaphore, semaphore d) monitor, monitor
d) monitor, monitor
Process are classified into different groups in a) shortest job scheduling algorithm b) round robin scheduling algorithm c) priority scheduling algorithm d) multilevel queue scheduling algorithm
d) multilevel queue scheduling algorithm
An IPC facility provides at least two operations : a) write & delete message b) delete & receive message c) send & delete message d) receive & send message
d) receive & send message
If the resources are always preempted from the same process, __________ can occur. a) deadlock b) system crash c) aging d) starvation
d) starvation
The state of a process is defined by: a) the final activity of the process b) the activity just executed by the process c) the activity to next be executed by the process d) the current activity of the process
d) the current activity of the process
The degree of multiprogramming is: a) the number of processes executed per unit time b) the number of processes in the ready queue c) the number of processes in the I/O queue d) the number of processes in memory
d) the number of processes in memory
Turnaround time is : a) the total waiting time for a process to finish execution b) the total time spent in the ready queue c) the total time spent in the running queue d) the total time from the completion till the submission of a process
d) the total time from the completion till the submission of a process
To ensure no preemption, if a process is holding some resources and requests another resource that cannot be immediately allocated to it : a) then the process waits for the resources be allocated to it b) the process keeps sending requests until the resource is allocated to it c) the process resumes execution without the resource being allocated to it d) then all resources currently being held are preempted
d) then all resources currently being held are preempted
_____ allow operating system services to be loaded dynamically. a. virtual machines b. file systems c. graphical users interfaces d. modules e. command line interfaces
d. modules
What are some other terms for kernel mode? a) supervisor mode b) system mode c)privileged mode d) unrestricted mode e) all of the above
e) all of the above
operating systems are designed primarily to maximize resource utilization a. PC b. Handheld computer c. Network d. Real-time e. Mainframe
e. Mainframe
The most common secondary storage device is ____. a. Random access memory b. Solid state transitor c. Magnetic disk d. tape drives e. Cache memory
magnetic disk
