Operating System Concepts - User and Kernel Threads

In the One-to-One threading model, each user-level thread maps to a ______ thread

Creating a user-level thread in the One-to-One model creates a ______ thread

The Many-to-Many threading model allows many user-level threads to be mapped to many ______ threads

The Two-level model is similar to Many-to-Many but allows a user thread to be bound to a ______ thread

Thread library provides programmer with API for creating and managing ______

Two primary ways of implementing thread libraries: Library entirely in ______ space

Pthreads may be provided either as ______-level or kernel-level

A POSIX standard API for thread creation and synchronization is known as ______

Java threads are managed by the ______

Rather than explicitly creating threads, Java allows thread creation around the ______ interface

Thread-local storage (TLS) allows each thread to have its own copy of ______

TLS is useful when you do not have control over the thread creation process, for example, when using a ______ pool

Local variables are visible only during a single function invocation, while TLS is visible across function invocations, similar to ______ data

Scheduler Activations in the context of thread models require communication to maintain the appropriate number of kernel threads allocated to the ______

In the context of Scheduler Activations, typically an intermediate data structure like lightweight process (LWP) is used between user and kernel threads, where each LWP is attached to a kernel ______

Scheduler Activations involve creating LWPs to determine how many ______ to create

The ForkJoinTask is an abstract base class. RecursiveTask and RecursiveAction classes extend ______ Task

Grand Central Dispatch is an Apple technology for macOS and iOS operating systems. It provides extensions to C, C++, and Objective-C languages, API, and runtime library. It allows identification of ______ sections

Intel Threading Building Blocks (TBB) is a template library for designing parallel C++ programs. It includes a serial version of a simple for loop. The same for loop can be written using TBB with ______ statement

OpenMP is a set of compiler directives and an API for C, C++, FORTRAN. It provides support for parallel programming in shared-memory environments. It identifies parallel regions – blocks of code that can run in ______

Grand Central Dispatch manages most of the details of threading. A block in Grand Central Dispatch is enclosed in “^{ }”. Blocks placed in a dispatch queue are assigned to an available thread in the thread pool when removed from the ______

Two types of dispatch queues in Grand Central Dispatch are: serial – blocks removed in FIFO order, queue is per process, called main queue, and ______ – removed in FIFO order but several may be removed at a time

For the Swift language, a task is defined as a closure – similar to a block, minus the caret. Closures are submitted to the queue using the ______() function

Semantics of fork() and exec() system calls involve the duplication of only the calling thread or ______ threads?

Thread Libraries handle various threading issues such as semantics of fork() and exec() system calls, signal handling, synchronous and asynchronous thread cancellation of target thread, thread-local storage, and ______ Activations

Fork-Join Parallelism in Java involves the ForkJoinTask as an abstract base class. RecursiveTask returns a result via the return value from the compute() method, while RecursiveAction does not return a ______