Week11 Quiz - Thread | Super Survey Maker

[APUE11&12] Which of the following items is shared by all thread in a process?

Stack

Program Counter

File descriptors

Errno variable

[APUE11&12] Spin locks are often used as low-level primitives to implement other types of locks, and can be implemented efﬁciently using ___ instruction.

[APUE11&12] Consider the following statements for a lock in thread programming. pthread_mutex_t MutexLock; pthread_mutex_init(&MutexLock, NULL); Which of the following statement will lock the mutex called MutexLock?

[APUE11&12] Spin locks are useful when running in real-time scheduling class that doesn’t allow ____.

[APUE11&12] When multiple threads of control share the same memory (a shared variable), one needs to make sure that each thread sees a consistent view of its data. Which of the following statements is not correct? Select one best answer.

If each thread uses variables while other threads don’t read or modify, no consistency problems will exist.

If a shared variable is read-only, there is no consistency problem.

When a thread can modify a variable that other threads can read or modify, then inconsistency problem can occur.

While a thread reads a variable, there is no consistency problem.

[APUE11&12] When the default action initialed by a thread is to terminate the process of this thread, what is expected?

A signal sent to a thread will terminate the entire process.

A signal sent to the process will terminate all the threads of the process.

A signal sent to a thread to be terminated but it is ignored by the process.

This is an invalid action which a thread cannot initiate.

[APUE11&12] Spin locks are useful when used in a(n) ___ kernel: besides providing a mutual exclusion mechanism, they block interrupts so an interrupt handler can’t deadlock the system by trying to acquire a spin lock that is already locked.

[APUE11&12] Consider the following function to be run by a thread. void *PrintHello(void *threadid) { . . . } pthread_t tid; int rc; Which of the following statement is correct to create a thread that executes a function called PrintHello?

Pthread_init(&tid, NULL, PrintHello, (void *)1);

Pthread_create(tid, NULL, *PrintHello, 1);

Pthread_create(&tid, NULL, &PrintHello, (void *)1);

Pthread_create(&tid, NULL, PrintHello, (void *)1);

Pthread_new(&tid, NULL, PrintHello, 1);

[APUE11&12] When a thread is terminated, a thread can arrange for a function to be called when it exits. Which of the following statement is not correct?

This function is known as thread cleanup handler.

More than one function can be established and registered for a thread for its exit.

This function is recorded in a stack

This function will be xecuted (in reverse order, if more than one, of the registration).

The process runs this function for the thread being terminated.

[APUE11&12] If any thread within a process calls exit, _Exit, or _exit, then what is expected?

The thread called exit will terminate.

The thread and its children will terminate.

The entire process (with all of its threads) terminates.

No effect to the thread as exit is only for process.

[APUE11&12] ___ is a synchronization mechanism that can be used to coordinate multiple threads working in parallel. This allows each thread to wait until all cooperating threads have reached the same point, and then continue executing from there.

[APUE11&12] ___ is like a mutex, except that instead of blocking a process by sleeping, the process is blocked by busy-waiting until the lock can be acquired.

[APUE11&12] A ___ is basically a lock that a thread does set (lock) before accessing a shared resource and release (unlock) when we’re done.

Week11 Quiz - Thread

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