Revisiting transactions in Ada

Abstract

Classical lock-based concurrency control does not scale with current and foreseen multi-core architectures, opening space for alternative concurrency control mechanisms. The concept of transactions executing concurrently in isolation with an underlying mechanism maintaining a consistent system state was already explored in fault-tolerant and distributed systems, and is currently being explored by transactional memory, this time being used to manage concurrent memory access. In this paper we discuss the use of Software Transactional Memory (STM), and how Ada can provide support for it. Furthermore, we draft a general programming interface to transactional memory, supporting future implementations of STM oriented to real-time systems.

Session summary

“…Miguel then presented an example of a potential (conceptual) implementation from [2], currently only addressing non-nested transactions: In the following discussion, the workshop made a note that the initial read snapshots and the final commit operations would need to be actually performed in memory, so transactional data (only the original not the multi-versions) would need to be volatile.…”

“…-In particular, STM would be analyzed in more detail as there was a position paper on the topic [2].…”