Holistic analysis of asynchronous real-time transactions with earliest deadline scheduling

In distributed real-time systems, an application is often modeled as a set of real-time transactions, where each transaction is a chain of precedence-constrained tasks. Each task is statically allocated to a processor, and tasks allocated on the same processor are handled by a single-processor scheduling algorithm. Precedence constraints among tasks of the same transaction are modeled by properly assigning scheduling parameters as offsets, jitters and intermediate deadlines. In this paper we address the problem of schedulability analysis of distributed real-time transactions under the earliest deadline first scheduling algorithm. We propose a novel methodology that reduces the pessimism introduced by previous methods by explicitly taking into account the offsets of the tasks. Moreover, we extend the analysis to account for blocking time due to shared resources. In particular, we propose two kinds of schedulability tests, CDO-TO and MDO-TO, and show, with an extensive set of simulatio...

• Type: Journal
• Year: 2007
• Where: JCSS
• Authors: Rodolfo Pellizzoni, Giuseppe Lipari
• Keywords: JCSS 2007, Precedence-constrained Tasks, Real-time Transactions, Single-processor Scheduling Algorithm