Input-Dependency Analysis for Hard Real-Time Software

Abstract

Abstract

Automatic Generation of Hints for Symbolic Traversal

“…3.2.) This use effectively corresponds to a reaching definition analysis [7]. Our abstraction will therefore need to capture information about whether input information can reach the definition of a variable.…”

The Periodic-Linear Model of Program Behavior Capture

“…IIPs are interesting candidates for trace driven analysis and profile feedback optimizations, since information common to any of their runs and input data can be extracted. IIPs, or input independent program sub-parts, can be identified through several approaches: input-dependency analysis by abstract interpretation [2]; static code analysis of control structures and conditionals by variable propagation; comparisons of traces resulting from a sufficient number of executions and showing the same execution behavior. Notice that this last approach can never be as reliable as the previous ones, but can give useful information relevant to the most frequent case.…”

“…A periodic polynomial is a polynomial whose coefficients are periodic numbers, i.e., a sequence of values indexed by the modulo of the variable relatively to the number of these values. For example, the periodic polynomial [1,2,3]x 2 + [3,4]x + 5 is equal to x 2 + 3x + 5 if x mod 3 = 0 and x mod 2 = 0.…”

“…For example, the sequence [3,3,7,13,11,23,15,33,19,43,23] where each element is respectively indexed by 0, 1, 2, ... is interpolated classically by the polynomial: which is a quite high degree polynomial exhibiting no apparent information about periodicity. Instead, periodic interpolation would give the following interpolation function: [2,5]x + [3, −2], showing a periodic behavior of period 2 and a linear relation between 2-spaced elements.…”

Guest Editorial: Introduction to the Special Issue

“…Following this spirit, the papers in this issue cover a wide range of ORDC topics, including an online hardware feasibility test scheme for thread admission control in the multithreaded Java microcontroller developed in the Komodo project (Brinkschulte, 2003), a non-blocking buffer mechanism which can facilitate communication of event messages from a producer to a consumer without causing any party to experience blocking (Kim, 2003), a fault-tolerant approach to handle transient upsets of multiple components in a TTA (Time-Triggered Architecture) system (Steiner et al, 2003), an exception handling framework for mobile agent systems to operate in the presence of agent server crash failures (Xu and Pears, 2003), two strategies to better estimate the bound for the worst-case execution time (WCET) of a code, that is, a programming strategy (WCET-oriented programming) and a code transformation strategy (the single-path conversion technique) (Gustafsson et al, 2003), and a system named VisiTrack for video based incremental tracking on mobile devices (Stichling et al, 2003). These papers do not only show how important the ORDC technology is in various applications, but they also present interesting problems in the current ORDC technology that may open up new areas of research in the future.…”