What is concurrency?

This increases the performance, efficiency, responsiveness, and resource usage of the system or application. Concurrency is a fundamental concept in modern computing.

Key aspects of concurrency

• Parallel execution: Concurrency allows for multiple tasks or processes to execute in parallel, while making use of available resources like threads. When one app uses the processor and the other uses a disk drive, say, it takes less time to run both apps simultaneously than to run them sequentially. This works to improve performance and reduce execution time.

• Interleaved execution: Concurrent tasks can be executed in an interleaved way, which executes each part of a task in a specific order. This allows for efficient use of system resources and greater responsiveness.

• Thread or process management: A thread is the smallest sequence of programmed instructions that can be managed by a scheduler or computer. Concurrency manages these threads, also called processes, to ensure they run simultaneously without interference or conflicts.

• Shared resource handling: To avoid conflicts and ensure reliable execution, concurrency requires the careful handling of shared resources like files, data structures, and network connections. It also introduces challenges in the form of deadlocks, synchronization complexities, and racing conditions. As multiple tasks must operate on limited shared resources, techniques such as locking and transactional memory are used to coordinate access and maintain data integrity.

Concurrency is a cornerstone of modern computer science. It allows a system to perform multiple processes simultaneously, and different parts to progress independently. It improves performance by enabling efficient resource use inside of systems, especially in multi-threaded or multi-process environments.