WordPress.com



VARDHAMAN COLLEGE OF ENGINEERING

(AUTONOMOUS)

Shamshabad – 501 218, Hyderabad

Regulations – VCE R11A/R14

OBJECTIVE TYPE QUESTIONS

Name of the subject: ES Subject Code: A1430

Semester: VII B.Tech/M.Tech/MCA/MBA

|Objective Type Questions & Answers |

|Unit-III |

|S.No |Question |Ans |

| |Each task has its own________. | |

| |Register | |

| |Stack |B |

| |Resource | |

| |Virtual Memory | |

| |A binary semaphore has ____ no. of states. | |

| |1 | |

| |2 |B |

| |3 | |

| |4 | |

| |ITC stands for__________ | |

| |Inter Terminal Communication | |

| |Inter Task Command |C |

| |Inter Task Communication | |

| |Inter Terminal Command | |

| |In which of the following, the message length is fixed | |

| |Mailboxes | |

| |Pipes |A |

| |Semaphores | |

| |Both (a) and (b) | |

| |Which of the following is not a semaphore value  | |

| |0 | |

| |1 |C |

| |-4 | |

| |All the above | |

| |The ______ state means that this task has not any resource for its execution even if microprocessor is available. | |

| |Ready | |

| |Running |D |

| |Blocked | |

| |Suspended | |

| |A task is ___________under most RTOS | |

| |Procedure | |

| |Routine |C |

| |Sub-Routine | |

| |Method | |

| |Lower priority task will be stopped by ________ RTOS when higher priority task is unblocked. | |

| |Preemptive | |

| |Non Preemptive |A |

| |FCFS | |

| |RoundRobin | |

| |Binary semaphore is also known as _______ | |

| |Mutex | |

| |Cluster |A |

| |Scheduler | |

| |Spooling | |

| |Mutex stands for __________ | |

| |Mutual exclusion | |

| |Mutual Task |A |

| |Mutual text | |

| |Mutual Timer | |

| |In RTOS ________ and _________ are used for allocation of memory buffers for tasks. | |

| |malloc() and calloc() | |

| |reqbuf() and getbuf() |B |

| |create() and init() | |

| |None | |

| |________ function returns a null pointer if no memory buffer is available to allocate for tasks. | |

| |getbuf() | |

| |reqbuf() |C |

| |relbuf() | |

| |None | |

| |_________ function initializes the memory buffers in RTOS. | |

| |init_buf_pool() | |

| |init_req_pool() |A |

| |init_mem_pool() | |

| |None | |

| |In init_mem_pool function, p_vmemory pointer refers to _______ | |

| |Buffer count | |

| |Memory buffer location | |

| |Buffer size |B |

| |None | |

| |Pipes in RTOS are ___________ oriented for Inter Task Communication | |

| |Bit | |

| |Byte |B |

| |Boolean | |

| |None | |

| |________________ are faster in inter task communication. | |

| |Semaphores | |

| |Events |B |

| |Pipes | |

| |MailBoxes | |

| |___________ is a boolean flag that tasks can set or reset and other tasks can wait for it. | |

| |Events | |

| |Message Queues |D |

| |Pipes | |

| |Mail Boxes | |

| |Task Structure will have its _________ data variables | |

| |Private | |

| |Public |A |

| |Shared | |

| |Global | |

| |__________ returns the execution control from interrupt routines to lower or higher priority task. | |

| |Jump | |

| |Scheduler |D |

| |CPU | |

| |ISR | |

| |Some RTOS uses ______ and __________ functions to enter, execute ISR | |

| |call and return | |

| |call and create |C |

| |call and exit | |

| |None | |

| |The principle of RTOS is: | |

| |Write short interrupt routines | |

| |no need of tasks for priority |D |

| |need tasks for inheritance | |

| |consider turning time slicing on | |

| |__________ protocol task determines if frame is addressed to telegraph | |

| |DDP  | |

| |ADSP |C |

| |Serial port | |

| |Interrupt | |

| |A task reserving a mutex cannot be _________ | |

| |Added | |

| |Released |B |

| |Deleted | |

| |Modified | |

| |The run out time of events is measured by | |

| |Counters | |

| |Timers |C |

| |Schedulers | |

| |Processes | |

| |RTOS Memory is divided into number of _________ | |

| |Pools | |

| |Chunks |A |

| |Threads | |

| |Tasks | |

| |________ Interrupt routines are efficient in RTOS design | |

| |Short | |

| |Long |A |

| |Far | |

| |None | |

| |Which of the following are commercially claimed RTOSs | |

| |Linux | |

| |Windows CE |D |

| |Mindows NT | |

| |Vx works | |

| |Identify which of these are real-time applications scenarios: | |

| |An on-line bus ticketing system | |

| |Printing of annual report of a company’s annual report |C |

| |Reconciling a day’s transactions in an account book of a small company | |

| |An aircrafts’ yaw control system | |

| |Where are the device drivers located in RTOSs with a microkernel: | |

| |In the kernel space | |

| |In the user space |A |

| |In separately allocated space which is neither kernel space nor user space. | |

| |None | |

| |Which of the following strategy is employed for overcoming the priority inversion problem? | |

| |Abandon the notion of priorities altogether | |

| |Have only two priority levels |C |

| |Allow for temporarily raising the priority of lower level priority process | |

| |Use pre-emptive policies strictly based on priorities | |

| |What feature of RTOS is supported by executing parts of a computation in different computer systems? | |

| |Computation speed up | |

| |Resource sharing |A |

| |Reliability | |

| |Communication | |

| |Which OS employs the techniques of fault tolerance and graceful degradation to ensure continuity of operation? | |

| |Batch Processing | |

| |Real time |B |

| |Distributed | |

| |Time sharing | |

| |Which of the following statement is false? | |

| |RTOS performs tasks in predictable amount of time | |

| |Windows 98 is RTOS |B |

| |Interrupts are used to develop RTOS | |

| |Kernel is the one of component of any OS | |

| |µC/OS-II provides the IPC functions (i) create (ii) connect (iii) post (iv) insert (v) post front (vi) pend (vii) delete (message) | |

| |(viii) listen (ix) accept (x) flush (xi) query (xii) close (xiii) delete (queue) for using message queue. | |

| |i, iii, v, vi, ix, x, xi and xiii |A |

| |ii, iv, vii, and x | |

| |all except ii | |

| |all except viii and ix | |

| |µC/OS-II task scheduling mechanism is | |

| |cooperative as well as preemptive | |

| |cyclic only |C |

| |preemptive only | |

| |preemptive as well as time slicing round robin. | |

| |µC/OS-II RTOS has the (i) mailbox functions with limit on number of messages per mailbox (ii) queue functions with limit on number | |

| |of messages per mailbox (iii) mailbox functions with one message pointer per mailbox (iv) queue functions with limit on number of |D |

| |message pointers per mailbox (v) OS scheduler lock and unlock functions | |

| |iii and iv | |

| |i, ii and v | |

| |i and ii | |

| |iii, iv and v | |

| |If deadlines are absolute then it is a | |

| |Hard real-time system | |

| |Soft real-time system |A |

| |Both (a) and (b) | |

| |None | |

| |How much time does it take to Release a semaphore of an RTOS on a 20MHz Intel 80386 | |

| |10 μs | |

| |6-38 μs |B |

| |12-38 μs | |

| |158 μs | |

| |Whenever the task writes to the flash memory ,it uses which RTOS delay function to suspend itself until the flash is available | |

| |again | |

| |vHandleFlashTask |B |

| |nanosleep | |

| |eFlashOp | |

| |FLASH_READ | |

| |Which of the following functions are a standard for RTOS interfaces are from POSIX | |

| |mq_open | |

| |mq_receive |D |

| |mq_send | |

| |All the above | |

| |How much time does it take to Get a semaphore of an RTOS on a 20MHz Intel 80386 | |

| |10 μs | |

| |6-38 μs |A |

| |12-38 μs | |

| |158 μs | |

| |While encapsulating Messege Queues which of the following is true | |

| |The functions vReadFlash and vWriteFlash execute in the context of whatever task happens to call them. | |

| |The functions vReadFlash and vWriteFlash do not execute in the context of flashtask |C |

| |Both (a) and (b) | |

| |Only (a) | |

| |How much time does it take to Switch between tasks of an RTOS on a 20MHz Intel 80386 | |

| |17-35 μs | |

| |6-38 μs |A |

| |49-68 μs | |

| |158 μs | |

| |How Code space can be saved in a system | |

| |By configuring RTOS correctly and by using limited number of I/O functions | |

| |By examining the output of C compiler for C constructs that require a lot of space and by writing the code in Assembly Language | |

| |instead of C | |

| |Both (a) and (b) |C |

| |Only (a) | |

| |How much time does it take to Create a task of an RTOS on a 20MHz Intel 80386 | |

| |17-35 μs | |

| |49-68 μs |C |

| |158 μs | |

| |36-57 μs | |

| |158 μs | |

| |To guarantee that a hard real-time system meets its deadlines one must ensure that each of the tasks has a | |

| |Predictable worst case execution time | |

| |Whose execution time depends on how much memory is free when it is called | |

| |Execution time which depends upon characteristics of other task that uses a semaphore. |A |

| |None | |

| |The timer which is used to interrupt periodically in an RTOS is called as | |

| |Hearbeat Timer | |

| |Hardware Timer |A |

| |Blocking Timer | |

| |TaskDelay Timer | |

| |Which of the following statement is true with respect to Queues | |

| |(i) Queues will allow to send information from one task to another | |

| |(ii) Putting messages into and taking messages out of queues is more microprocessor –intensive |D |

| |(iii) Queues offer more opportunities to inset bugs into the code | |

| |Only (i) is true | |

| |Both (i) and (iii) are true | |

| |Both (i) and (ii) are true | |

| |All the three statements are true | |

| |Which of the following standard functions are used for memory allocation in any RTOSs | |

| |malloc | |

| |free |C |

| |Both (a) and (b) | |

| |None | |

| |What does Board Support Packages contain | |

| |Driver software for only common hardware components | |

| |Driver software for all hardware components |A |

| |Both (a) and (b) | |

| |None | |

| |The interval between heartbeat timer interrupts is called as | |

| |Tick | |

| |System Tick |B |

| |Elapsed Tick | |

| |Tick Delay | |

| |The most common RTOS timing services include | |

| |A task can block itself for a specified number of system ticks | |

| |A task can limit how many system ticks it will wait for a semaphore, queue etc |D |

| |Our Code can tell the RTOS to call a specified function after a specified number of system ticks | |

| |All the above | |

| |The basic building block of software written under an RTOS is called as | |

| |Semaphore | |

| |Scheduler | |

| |Task | |

| |Real-time Kernel |C |

| |The standard Task states in an RTOS include | |

| |Running, Suspended, Delayed | |

| |Running, Ready, Dormant |C |

| |Running, Ready, Blocked | |

| |Running, Ready, Suspended | |

| |Which of the shared function is used to find bugs in shared-data problems when more than one tasks occur | |

| |vCountErrors | |

| |cErrors | |

| |cNewErrors |A |

| |none | |

| |Which of the following is not a re-entrant function rule | |

| |It may not use variables in a non atomic way unless they are stored on a stack of the task that called the function | |

| |It may not call any other function s that are not themselves re-entrant |C |

| |It may use the hardware in a non atomic way | |

| |None | |

| |A function that works properly even if it is called by more than one task is called as | |

| |Reentrant | |

| |Semaphore |A |

| |Mutex | |

| |Priority Inversion | |

| |What are the methods used for protecting the shared data |D |

| |Disabling interrupts | |

| |Taking Semaphores | |

| |Disabling task switches | |

| |All the above | |

| |If a task tries to take a semaphore when the integer is equal to zero , then the task will block .These semaphores are called as |B |

| |Resource Semaphores | |

| |Counting Semaphores | |

| |Mutex Semaphores | |

| |Binary Semaphores | |

| |RTOS is used in most embedded systems when the system does |D |

| |Concurrent processing of multiple real time process | |

| |Real time processing of multiple processes | |

| |Sequential processing of multiple processes when the tasks have real time constraints. | |

| |Concurrent processing of multiple processes, tasks have real-time constraints and deadlines, and high priority tasks pre-empts low | |

| |priority tasks as per the rea time constraints | |

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download