Operating System Multiple Choice Questions on “Signal Handling”.
1. Signals that occur at the same time, are presented to the process ____________
a) one at a time, in a particular order
b) one at a time, in no particular order
c) all at a time
d) none of the mentioned
Answer: b
2. Which of the following is not TRUE?
a) Processes may send each other signals
b) Kernel may send signals internally
c) A field is updated in the signal table when the signal is sent
d) Each signal is maintained by a single bit
Answer: c
Clarification: A field is updated in the process table when the signal is sent.
3. Signals of a given type ____________
a) are queued
b) are all sent as one
c) cannot be queued
d) none of the mentioned
Answer: b
Clarification: The signal handler will be invoked only once.
4. The three ways in which a process responds to a signal are ____________
a) ignoring the signal
b) handling the signal
c) performing some default action
d) all of the mentioned
Answer: d
Clarification: None.
5. Signals are identified by ____________
a) signal identifiers
b) signal handlers
c) signal actions
d) none of the mentioned
Answer: a
Clarification: None.
6. When a process blocks the receipt of certain signals?
a) The signals are delivered
b) The signals are not delivered
c) The signals are received until they are unblocked
d) The signals are received by the process once they are delivered
Answer: a
Clarification: None.
7. The _______ maintains pending and blocked bit vectors in the context of each process.
a) CPU
b) Memory
c) Process
d) Kernel
Answer: d
Clarification: None.
8. In UNIX, the set of masked signals can be set or cleared using the ________ function.
a) sigmask
b) sigmaskproc
c) sigprocmask
d) sigproc
Answer: c
Clarification: None.
9. The usefulness of signals as a general inter process communication mechanism is limited because ____________
a) they do not work between processes
b) they are user generated
c) they cannot carry information directly
d) none of the mentioned
Answer: c
Clarification: None.
10. The usual effect of abnormal termination of a program is ____________
a) core dump file generation
b) system crash
c) program switch
d) signal destruction
Answer: a
Clarification: None.
11. In UNIX, the abort() function sends the ________ signal to the calling process, causing abnormal termination.
a) SIGTERM
b) SIGSTOP
c) SIGABORT
d) SIGABRT
Answer: d
Clarification: None.
12. In most cases, if a process is sent a signal while it is executing a system call ____________
a) the system call will continue execution and the signal will be ignored completely
b) the system call is interrupted by the signal, and the signal handler comes in
c) the signal has no effect until the system call completes
d) none of the mentioned
Answer: c
Clarification: None.
13. A process can never be sure that a signal it has sent _____________
a) has which identifier
b) has not been lost
c) has been sent
d) all of the mentioned
Answer: b
Clarification: None.
14. In UNIX, the ______________ system call is used to send a signal.
a) sig
b) send
c) kill
d) sigsend
Answer: c