From Code to Weakly Hard Constraints: A Pragmatic End-to-End Toolchain for Timed C
Ref: CISTER-TR-190905 Publication Date: 18 to 21, Feb, 2020
From Code to Weakly Hard Constraints: A Pragmatic End-to-End Toolchain for Timed C
Ref: CISTER-TR-190905 Publication Date: 18 to 21, Feb, 2020Abstract:
Complex real-time systems are traditionally developed
in several disjoint steps: (i) decomposition of applications
into sets of recurrent tasks, (ii) worst-case execution time estimation,
and (iii) schedulability analysis. Each step is already
in itself complex and error-prone, and the composition of all
three poses a nontrivial integration problem. In particular, it is
challenging to obtain an end-to-end analysis of timing properties
of the whole system due to practical differences between the
interfaces of tools for extracting task models, execution time
analysis, and schedulability tests. To address this problem, we
propose a seamless and pragmatic end-to-end compilation and
timing analysis toolchain, where source programs are written
in a real-time extension of C, called Timed C. The toolchain
automatically translates timing primitives into executable code,
measures execution times, and verifies temporal correctness using
an extended schedulability test for non-preemptive generalized
multiframe task sets. Novel aspects of our approach are: (i) both
soft and firm tasks can be expressed at the programming
language level and stated timing requirements are automatically
verified by the schedulability test, and (ii) the schedulability test
outputs per-job response-time information that enables a new
approach to sensitivity analysis. Specifically, we perform a weakly
hard sensitivity analysis that determines the worst-case execution
time margins for the strongest still-satisfied (M;K) constraint,
where M = m_1 + … + m_N denotes the number of deadline
misses across the entire task set, and K = {k_1; … ; k_N} is the
set of windows of interest of the different tasks. The toolchain is
implemented as a source-to-source compiler, freely available as
open source, and conveniently distributed as a Docker container.
Saranya Natarajan
Mitra Nasri
Geoffrey NelissenDocument:
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Download40th IEEE Real-Time Systems Symposium (RTSS 2019), pp 167-180.
York, United Kingdom.
DOI:10.1109/RTSS46320.2019.00025.
ISBN: 978-1-7281-6463-2.
ISSN: 2576-3172.
Notes: RTSS 2019 originally postponed from December 2019 (Hong-Kong) to February 2020 (York, UK) was cancelled.
Record Date: 18, Sep, 2019