CppCon 2024

Task-based concurrency offers benefits in streamlining software and enhancing overall responsiveness. Numerous frameworks build upon this approach by furnishing abstractions that harness the capabilities of modern multi-core processors and distributed computing environments. These frameworks achieve this by facilitating the creation of task graphs, which simplify the management of task execution order and dependencies between tasks.

However, these frameworks are typically not well suited for use in low latency environments where every nanosecond matters, and any additional overhead introduced by managing task graphs can impact the system's ability to meet stringent latency requirements.

This presentation introduces Work Contracts, a novel approach specifically tailored for low-latency environments, which re-imagines both task-based concurrency as well as tasks themselves. We present an innovative lock free, often wait free, data structure designed to significantly enhance scalability in parallel task distribution, particularly under high contention.  Additionally, we introduce concepts which enhance tasks with internal state allowing for single threaded or parallel execution, recurring execution, and deterministic asynchronous task destruction. 

Finally, we examine usage cases for Work Contracts to showcase the advantages that this solution makes possible, resulting in cleaner, more manageable, and more scalable software which is well suited for low latency applications.