Operating Systems Concurrency Quiz

The ability of an operating system to handle multiple tasks or processes seemingly at the same time, enhancing efficiency and responsiveness.

Processes whose state is independent of other processes. Their results are dependent only on their input, and their termination does not affect other processes.

Processes that share their state with other processes. Their results are unpredictable and can be influenced by the order of execution, and terminating one may affect others.

A technique used in operating systems to control access to shared resources by multiple processes, ensuring their execution does not interfere with each other.

A technique used in operating systems that allows multiple tasks to run simultaneously on multiple processors or through context switching on a single processor, providing the illusion that multiple processes are running concurrently.

The execution of multiple processes or threads on a single processor by rapidly switching between them, giving the appearance of concurrent execution. It's like a chef juggling multiple tasks in a kitchen.

When processes need to share resources, like memory, files, or hardware devices, concurrency control is crucial to avoid interference and incorrect results.

Concurrency control is essential for modern operating systems to handle multitasking, increase responsiveness, and optimize performance for users and applications.

A shared variable that indicates a process's intention to enter the critical section. It is typically a boolean value, with true indicating the intention and false indicating otherwise.

A shared variable used to determine which process has priority for accessing the critical section. It can take the value 0 or 1, representing the two processes P0 and P1 respectively.

The section of code where a process prepares to access the critical section. It ensures mutual exclusion by using synchronization mechanisms.

The section of code that contains the shared resource or critical code. Only one process can execute this code at a time.

The section of code where a process releases its claim to the critical section, allowing other processes to enter.

The section of code outside the critical section, where a process can perform other tasks.

A synchronization mechanism that ensures that at most one process can access a critical section at any given time. It is designed for two processes.

The state where two or more processes are blocked, each waiting for a resource that is held by another process in the deadlock.

A situation where the outcome of multiple threads executing concurrently on shared resources depends on the order in which they execute.

The problem of designing a way for multiple processes to access shared resources without causing data inconsistencies.

A requirement for a solution to the critical section problem. It ensures that only one process can execute within the critical section at a time.

A requirement for a solution to the critical section problem. It ensures that if no process is in the critical section, and some processes are waiting to enter, then the decision about which process will enter next is made fairly and not endlessly delayed.

A requirement for a solution to the critical section problem. It ensures that there is a limit on the number of times another process can enter the critical section after a given process has requested to enter.

A potential outcome of a race condition, where the actions of multiple threads can lead to an inconsistent or unexpected result.

Techniques used to ensure that multiple processes can access shared resources safely and without causing inconsistencies.

A synchronization mechanism that allows only one thread to access a shared resource at a time. It's like a single-lane bridge where cars have to take turns.

A semaphore that acts like a mutex but doesn't track ownership. Multiple threads can access a resource as long as the semaphore count is positive.

A semaphore that allows a fixed number of threads to access a shared resource simultaneously. It's like having multiple lanes on a bridge.

A lightweight synchronization mechanism where a thread continuously checks (or 'spins') for a lock to become available. It's efficient for short waiting times, like a busy phone line that you keep trying to call.

High-level synchronization constructs that encapsulate data, locks, and condition variables in a single unit. They provide a structured way to manage shared resources.

Used alongside mutexes to allow threads to wait for specific conditions to be met. Threads can 'sleep' while waiting and be woken up when the condition is signaled.

Locks that allow multiple threads to read a resource simultaneously but only one thread to write at a time. They're ideal for scenarios where reads are more frequent than writes.

A mechanism that prevents priority inversion issues. It ensures that a high-priority process blocked by a lower-priority process is blocked for the shortest possible time.

A mechanism used to protect critical sections of code that access shared resources, ensuring only one process can modify the resource at a time. It involves acquiring a lock before entering the critical section and releasing it upon exiting.

When a thread (holding the mutex) sleeps or is interrupted by a higher priority process, no other threads can access the critical section, even if the resource isn't being used. This leads to waiting and potential resource inefficiency.

A signaling mechanism where a thread waiting on a semaphore can be awakened by another thread. It is useful for coordinating access to a limited number of resources among multiple threads.

Used to ensure data consistency and integrity by allowing only one thread to modify a resource at a time. It prevents race conditions, where multiple threads try to update the same resource simultaneously, leading to errors.

Used to protect shared resources such as variables, data structures, and databases. This ensures that threads can access and modify these resources safely without interfering with each other.

Used to synchronize actions between threads, like waiting for a specific event or signal before proceeding, ensuring all threads are coordinated.

Used to manage access to resources like databases and files, guaranteeing exclusive access to one thread at a time. This prevents data corruption and ensures consistent data operations.

Used for inter-process communication (IPC) in some systems, allowing synchronization between processes that share resources, ensuring coordinated resource access.

A synchronization mechanism used to ensure only one process can access a shared resource at a time. Imagine a single-lane bridge with a traffic light - only one car can cross at a time.

A mechanism for coordinating the order of execution of multiple processes. Imagine a set of instructions where each process needs to wait for a specific signal before it can continue.

Semaphores can be used to restrict access to a limited number of resources, like printers, devices, or files. Imagine a library with a limited number of books - only a certain number of people can borrow a book at a time.

A synchronization problem where multiple readers can access a data resource simultaneously, but only one writer can access it at a time. Imagine a library where multiple readers can read a book, but only one person can write a new book at a time.

Semaphores can help prevent deadlocks by controlling the order of resource allocation. Think of a train track with multiple trains - a semaphore can ensure that no train blocks another by controlling the switching points.

A condition variable function that releases a lock, puts the thread to sleep, and waits for the condition to be signaled. When the condition is signaled, the thread wakes up, re-acquires the lock, and continues execution.

A condition variable function that wakes up one waiting thread if any. The caller must hold the lock that was used in the wait call.