OMG OMG-OCRES-I200 問題集

質問 1：
Which class acts as the factory used to construct DataReader objects?
A. DomainParticipant
B. Publisher
C. DomainParticipantFactory
D. Subscriber
正解：D

質問 2：
In the Lightweight Time Service, a value of type "TimeT" indicates ___.
A. the number of seconds passed sincemidnight, January 1, 1970, UTC
B. a relative time, with the "tv_sec" field containing the number of elapsed seconds, and "tv_usec"
containing elapsed microseconds
C. the number of seconds (tv_sec) and nanoseconds (tv_nsec) passed since the beginning of the POSIX
epoch
D. a 64-bit value of relative elapsed or absolute time, in units of 100 nanoseconds
正解：D

質問 3：
The primary requirement for an RTOS is to---------------
A. enable the application to meet both its functional and temporal requrements
B. enable fast control and data transfer to critical system devices
C. maximize application speed and minimize memory utilization
D. permit the application to efficiently access all resources (e.g., I/O and memory)
正解：A

質問 4：
Which two are POSIX real-time extensions? (Choose two.)
A. direct cyclic executive support
B. priority-based preemptive task scheduling
C. suspend / resume API's
D. task synchronization
正解：B,D

質問 5：
A scheduler runs tasks to completion instead of pre-empting tasks by time slicing or according to priority.
What two actions will occur? (Choose two.)
A. Share the processor time fairly among ready tasks
B. Maximize the number of completed tasks per unit of time
C. Honor the commitment made to complete the task once it has begun executing
D. Minimize the task scheduling and context switching overheads
正解：C,D

質問 6：
Which two of these correctly characterise "end to end" predictability in a fixed priority CORBA system?
(Choose TWO)
A. respecting thread priorities between CORBA clients and servers
B. bounding the duration of thread priority inversions during end-to-end processing
C. minimizing the latencies of operation invocations
D. bounding the duration of memory access times
正解：A,B

質問 7：
Which scenarios could cause a DataReader to get a sample with instance_state
NOT_ALIVE_NO_WRITERS? Select THREE
A. call tounregister_instance() on a matched DataWriter
B. call towrite() on a matched DataWriter
C. deletion of a matchedDataWriter
D. call todispose() on a matched DataWriter
E. loss of communications (e.g. network outage) with a matchedDataWriter
正解：A,C,E

質問 8：
What are two instances when the Lightweight Naming Service NamingContext raises Exceptions?
(Choose two.)
A. when an object is bound to a scoped name
B. when the operation applied to the binding type is incorrect
C. when a name is not bound to a context
D. when an attempt is made to destroy an emptyNamingContext
正解：B,C

質問 9：
The priority of a runnable task blocked on a resource request is temporarily changed to be the same as
the priority of another task. Which two phrases could describe the new priority? (Choose two.)
A. The ceiling priority of the resource on which the lower priority task is blocked
B. The priority of the higher priority task being blocked by the lower priority one
C. The priority of the highest priority task
D. The priority of the lowest priority task which uses the resource
正解：A,B