Challenge your understanding of Pthreads programming with this quiz focused on key API functions, thread creation, synchronization, and best practices. Ideal for those looking to reinforce foundational multi-threading concepts using the Pthreads library.
Which function is used to create a new thread in the Pthreads library?
Explanation: The correct function to create a new thread in the Pthreads library is pthread_create. pthread_start, thread_begin, and thread_init are not valid Pthreads functions; they are either incorrect names or do not exist in the standard API. Only pthread_create matches the official Pthreads syntax for thread creation.
After creating threads, which Pthreads function allows one thread to wait for another to finish before proceeding?
Explanation: pthread_join is used to block the calling thread until the specified thread terminates, ensuring proper synchronization. pthread_synchronize is not an actual Pthreads function, while pthread_end and pthread_close are incorrect and not associated with joining threads. Therefore, pthread_join is the correct answer.
What function is called to lock a mutex and ensure exclusive access to a shared resource in a critical section?
Explanation: pthread_mutex_lock is the correct method for locking a mutex in Pthreads. pthread_mutex_enable and mutex_acquire are not valid Pthreads function names, and thread_mutex_lock is a misspelling of the actual function. Only pthread_mutex_lock is correct for locking a mutex.
Which function should a Pthread call to terminate itself and optionally return a value to a joining thread?
Explanation: pthread_exit is the correct Pthreads function for terminating a thread and optionally returning a value. pthread_stop and exit_thread are not functions within Pthreads, while thread_exit is a common mistake but not a valid symbol. pthread_exit handles thread termination in the Pthreads context.
Before creating a thread with custom attributes, which function initializes a pthread_attr_t variable?
Explanation: pthread_attr_init initializes a pthread_attr_t object for customized thread creation. pthread_attr_setup and attr_create do not exist in the API, and thread_attr_init is a typo. Only pthread_attr_init properly prepares the attribute structure for use.
Which function is used to mark a thread as detached so that its resources are automatically freed upon termination?
Explanation: pthread_detach is the official Pthreads function to detach a thread, enabling its resources to be freed automatically. thread_free and detach_thread might sound plausible but do not exist in the API, and pthread_release is not correct. Thus, pthread_detach is the only appropriate answer.
After finishing operations on a shared variable, which Pthreads function is used to release the mutex lock?
Explanation: pthread_mutex_unlock is the correct function to release a mutex lock after use. pthread_mutex_release and unlock_mutex are not officially recognized Pthreads functions, and thread_mutex_unlock is an incorrect name. Only pthread_mutex_unlock properly unlocks a mutex.
What is the required return type of the function passed to pthread_create as the thread’s start routine?
Explanation: The start routine for pthread_create must return a void pointer (void*), allowing data to be sent back to the joining thread. Returning int, char*, or void does not conform to the required prototype and can result in undefined behavior. Only void* is correct for compatibility and standard compliance.
Which data type does Pthreads use to store thread identifiers returned by pthread_create?
Explanation: pthread_t is the data type used to represent thread identifiers in Pthreads. pthread_id, thread_t, and tid_t are either incorrect or not part of the Pthreads specification. Only pthread_t is recognized by the official library and used by pthread_create.
Where is the value returned by a thread’s start routine made available to the joining thread in pthread_join?
Explanation: The correct method is to pass a pointer as the second argument to pthread_join, which receives the return value from the thread’s start routine. pthread_join itself returns an error code, not the thread’s result. Global variables and static arrays are not required or standard means for this operation. Thus, the second argument pointer is the accepted practice.