3,423 research outputs found
A Concurrency-Agnostic Protocol for Multi-Paradigm Concurrent Debugging Tools
Today's complex software systems combine high-level concurrency models. Each
model is used to solve a specific set of problems. Unfortunately, debuggers
support only the low-level notions of threads and shared memory, forcing
developers to reason about these notions instead of the high-level concurrency
models they chose.
This paper proposes a concurrency-agnostic debugger protocol that decouples
the debugger from the concurrency models employed by the target application. As
a result, the underlying language runtime can define custom breakpoints,
stepping operations, and execution events for each concurrency model it
supports, and a debugger can expose them without having to be specifically
adapted.
We evaluated the generality of the protocol by applying it to SOMns, a
Newspeak implementation, which supports a diversity of concurrency models
including communicating sequential processes, communicating event loops,
threads and locks, fork/join parallelism, and software transactional memory. We
implemented 21 breakpoints and 20 stepping operations for these concurrency
models. For none of these, the debugger needed to be changed. Furthermore, we
visualize all concurrent interactions independently of a specific concurrency
model. To show that tooling for a specific concurrency model is possible, we
visualize actor turns and message sends separately.Comment: International Symposium on Dynamic Language
A Machine-Independent Debugger--Revisited
Most debuggers are notoriously machine-dependent, but some recent research
prototypes achieve varying degrees of machine-independence with novel designs.
Cdb, a simple source-level debugger for C, is completely independent of its
target architecture. This independence is achieved by embedding symbol tables
and debugging code in the target program, which costs both time and space. This
paper describes a revised design and implementation of cdb that reduces the
space cost by nearly one-half and the time cost by 13% by storing symbol tables
in external files. A symbol table is defined by a 31-line grammar in the
Abstract Syntax Description Language (ASDL). ASDL is a domain-specific language
for specifying tree data structures. The ASDL tools accept an ASDL grammar and
generate code to construct, read, and write these data structures. Using ASDL
automates implementing parts of the debugger, and the grammar documents the
symbol table concisely. Using ASDL also suggested simplifications to the
interface between the debugger and the target program. Perhaps most important,
ASDL emphasizes that symbol tables are data structures, not file formats. Many
of the pitfalls of working with low-level file formats can be avoided by
focusing instead on high-level data structures and automating the
implementation details.Comment: 12 pages; 6 figures; 3 table
A comparative evaluation of dynamic visualisation tools
Despite their potential applications in software comprehension, it appears that dynamic visualisation tools are seldom used outside the research laboratory. This paper presents an empirical evaluation of five dynamic visualisation tools - AVID, Jinsight, jRMTool, Together ControlCenter diagrams and Together ControlCenter debugger. The tools were evaluated on a number of general software comprehension and specific reverse engineering tasks using the HotDraw objectoriented framework. The tasks considered typical comprehension issues, including identification of software structure and behaviour, design pattern extraction, extensibility potential, maintenance issues, functionality location, and runtime load. The results revealed that the level of abstraction employed by a tool affects its success in different tasks, and that tools were more successful in addressing specific reverse engineering tasks than general software comprehension activities. It was found that no one tool performs well in all tasks, and some tasks were beyond the capabilities of all five tools. This paper concludes with suggestions for improving the efficacy of such tools
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