Lars Schütze |
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Phone Fax Visitor's Address |
+49 351 463-43733 +49 351 463-39995 Chair for Compiler Construction |
Lars has a bachelor and master degrees in computer science from the TU Dresden and had worked as researcher at the Software Technology Group headed by Prof. Uwe Aßmann. Lars will work on his PhD in the context of the RoSI project, which studies role-based software infrastructures for continuous-context-sensitive systems.
Dispatch for Role-Oriented Programming Languages
During the lifetime of an object-oriented program objects collaborate with other objects. This is a result of the different roles an object plays at runtime yielding adaptations to the behavior of the role-playing object. Role-oriented programming is an extension to object-oriented programming where those collaborations are first-class citizens of the language. This provides means to separate the different context-dependent behaviors that can be attached to objects at runtime.
In traditional object-oriented programming languages the dispatch is dependent on the type of the receiver and the method name including its arguments (2-dimensional dispatch). However, role-oriented programming languages take the role of the sender and also the current context into account forming a 4-dimensional dispatch. This dispatch is currently not optimized as dispatches before (e.g., vtables, inline caches, devirtualization), but implemented as abstraction on top of the host language (e.g., as DSL or library).
Lars is interested in different approaches to provide optimizations for role-oriented method dispatch. This includes special-purpose compilers that extend the Java compiler, or library approaches that are seamlessly embedded into the language making use of the invokedynamic bytecode instruction. Providing a new interpreter for role-oriented programming languages allows to research the impact of different object models on the performance of the resulting virtual machine.
Benchmarking Role-Oriented Programming Languages
Benchmarks provide an insight into the performance characteristics of the system under test. For programming languages, beside benchmarking whole programs (i.e., mandelbrot) it is also interesting to benchmark single parts in isolation (e.g., method dispatch, memory consumption).
However, there is no pedant to established benchmarks such as SPECjvm for role-oriented programming languages. Because of the many different features of role-oriented programming languages it is hard to develop comparable benchmarks.
This project is interested to develop a benchmark suite that is able to handle a variety of different role-oriented programming languages yet providing insightful information that allows to compare and reason about the performance of each approach.
Some possible topics for Bachelor/Master/Diploma Thesis or SHK/WHK in the following directions:
Dispatch optimization and programming language implementation
Role-oriented programming will be a key concept in realizing future complex, adaptive software systems. Therefore, the object-oriented paradigm is extended with roles. Objects can play and remove roles at runtime. Playing a role changes the type of objects and may add or change attributes and methods to the object. Moreover, roles describe dynamic relationships between other objects
Possible project topics include:
- Virtual Machine support for contextual roles
- Benchmarking and Evaluating the Performance of Role-Oriented Programming Languages [PDF]
2023
- Lars Schütze, Jeronimo Castrillon, "Towards Virtual Machine Support for Contextual Role-Oriented Programming Languages", Proceedings of the 15th ACM International Workshop on Context-Oriented Programming and Advanced Modularity (COP'23), Association for Computing Machinery, pp. 1–8, New York, NY, USA, Jul 2023. [doi] [Bibtex & Downloads]
Towards Virtual Machine Support for Contextual Role-Oriented Programming Languages
×Reference
Lars Schütze, Jeronimo Castrillon, "Towards Virtual Machine Support for Contextual Role-Oriented Programming Languages", Proceedings of the 15th ACM International Workshop on Context-Oriented Programming and Advanced Modularity (COP'23), Association for Computing Machinery, pp. 1–8, New York, NY, USA, Jul 2023. [doi]
Abstract
Adaptive software becomes more and more important as computing is increasingly context-dependent. Runtime adaptability can be achieved by dynamically selecting and applying context-specific code. Role-oriented programming has been proposed as a paradigm to enable runtime adaptive software by design. Roles change the objects’ behavior at runtime, thus adapting the software to a given context. Most approaches focus on optimizing language implementations neglecting the fact that the generated code is a verbose description of contextual roles in an object-oriented paradigm, which incurs an overhead. This paper takes a novel approach to reduce the semantic gap. We propose ObjectTeams/Truffle, to the best of our knowledge, the first virtual machine that optimizes the dispatch of contextual roles. We evaluate the implementation with a benchmark for role-oriented programming languages achieving a speedup of up to 2.49\texttimes over the reference implementation ObjectTeams/Java and 1.2\texttimes over an optimized version ObjectTeams/Java using Dispatch Plans.
Bibtex
@InProceedings{schuetze_cop23,
author = {Sch\"{u}tze, Lars and Castrillon, Jeronimo},
booktitle = {Proceedings of the 15th ACM International Workshop on Context-Oriented Programming and Advanced Modularity (COP'23)},
title = {Towards Virtual Machine Support for Contextual Role-Oriented Programming Languages},
doi = {10.1145/3605154.3605851},
isbn = {9798400702440},
location = {Seattle, USA},
pages = {1–8},
publisher = {Association for Computing Machinery},
series = {COP '23},
url = {https://doi.org/10.1145/3605154.3605851},
abstract = {Adaptive software becomes more and more important as computing is increasingly context-dependent. Runtime adaptability can be achieved by dynamically selecting and applying context-specific code. Role-oriented programming has been proposed as a paradigm to enable runtime adaptive software by design. Roles change the objects’ behavior at runtime, thus adapting the software to a given context. Most approaches focus on optimizing language implementations neglecting the fact that the generated code is a verbose description of contextual roles in an object-oriented paradigm, which incurs an overhead. This paper takes a novel approach to reduce the semantic gap. We propose ObjectTeams/Truffle, to the best of our knowledge, the first virtual machine that optimizes the dispatch of contextual roles. We evaluate the implementation with a benchmark for role-oriented programming languages achieving a speedup of up to 2.49\texttimes{} over the reference implementation ObjectTeams/Java and 1.2\texttimes{} over an optimized version ObjectTeams/Java using Dispatch Plans.},
address = {New York, NY, USA},
month = jul,
numpages = {8},
year = {2023},
}Downloads
2307_Schuetze_COP [PDF]
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2022
- Lars Schütze, Cornelius Kummer, Jeronimo Castrillon, "Guard the Cache: Dispatch Optimization in a Contextual Role-oriented Language", Proceedings of the 14th ACM International Workshop on Context-Oriented Programming and Advanced Modularity (COP'22), Association for Computing Machinery, pp. 27–34, New York, NY, USA, Jun 2022. [doi] [Bibtex & Downloads]
Guard the Cache: Dispatch Optimization in a Contextual Role-oriented Language
×Reference
Lars Schütze, Cornelius Kummer, Jeronimo Castrillon, "Guard the Cache: Dispatch Optimization in a Contextual Role-oriented Language", Proceedings of the 14th ACM International Workshop on Context-Oriented Programming and Advanced Modularity (COP'22), Association for Computing Machinery, pp. 27–34, New York, NY, USA, Jun 2022. [doi]
Abstract
Adaptive programming models are increasingly important as context-dependent software conquers more domains. One such a model is role-oriented programming where behavioral changes are implemented by objects playing and renouncing roles. As with other adaptive models, the overhead introduced by source code adaptations is a major showstopper for role-oriented programs. This is in part because the optimizations of object-oriented virtual machines (VMs) do not provide the same performance gains when applied to role-oriented programs. Recently, dispatch plans have been shown to enable optimizations beyond those in VMs, thereby improving the performance of role programs with low variability. This paper introduces guarded dispatch plans, an extension of dispatch plans with a context-aware guarding mechanism that allows reuse in high-variability scenarios. Fine-grained guards use run-time feedback to partially reuse dispatch plans across call sites when contexts are changing. We present an algorithm to construct and compose guarded dispatch plans and provide a reference implementation of the approach. We show that our approach is able to gracefully degrade into a default dispatch approach when variability increases. The implementation is evaluated with synthetic benchmarks capturing different characteristics. Compared to the state-of-the-art implementation in ObjectTeams we achieved a mean speedup of 3.3 \texttimes in static cases, 3.0 \texttimes at low variability and the same performance in highly dynamic cases.
Bibtex
@InProceedings{schuetze_cop22,
author = {Sch\"{u}tze, Lars and Kummer, Cornelius and Castrillon, Jeronimo},
booktitle = {Proceedings of the 14th ACM International Workshop on Context-Oriented Programming and Advanced Modularity (COP'22)},
title = {Guard the Cache: Dispatch Optimization in a Contextual Role-oriented Language},
doi = {10.1145/3570353.3570357},
isbn = {9781450399869},
pages = {27--34},
publisher = {Association for Computing Machinery},
series = {COP '22},
url = {https://doi.org/10.1145/3570353.3570357},
abstract = {Adaptive programming models are increasingly important as context-dependent software conquers more domains. One such a model is role-oriented programming where behavioral changes are implemented by objects playing and renouncing roles. As with other adaptive models, the overhead introduced by source code adaptations is a major showstopper for role-oriented programs. This is in part because the optimizations of object-oriented virtual machines (VMs) do not provide the same performance gains when applied to role-oriented programs. Recently, dispatch plans have been shown to enable optimizations beyond those in VMs, thereby improving the performance of role programs with low variability. This paper introduces guarded dispatch plans, an extension of dispatch plans with a context-aware guarding mechanism that allows reuse in high-variability scenarios. Fine-grained guards use run-time feedback to partially reuse dispatch plans across call sites when contexts are changing. We present an algorithm to construct and compose guarded dispatch plans and provide a reference implementation of the approach. We show that our approach is able to gracefully degrade into a default dispatch approach when variability increases. The implementation is evaluated with synthetic benchmarks capturing different characteristics. Compared to the state-of-the-art implementation in ObjectTeams we achieved a mean speedup of 3.3 \texttimes{} in static cases, 3.0 \texttimes{} at low variability and the same performance in highly dynamic cases.},
address = {New York, NY, USA},
month = jun,
numpages = {8},
year = {2022},
}Downloads
2206_schuetze_COP [PDF]
Permalink
- Ilja Shmelkin, Lars Schütze, Tim Kluge, "Modeling flexible Monitoring Systems with a Role-Based Control Loop", In Proceeding: COP 2022: International Workshop on Context-Oriented Programming and Advanced Modularity (collocated with ECOOP), ACM, Jun 2022. [doi] [Bibtex & Downloads]
Modeling flexible Monitoring Systems with a Role-Based Control Loop
×Reference
Ilja Shmelkin, Lars Schütze, Tim Kluge, "Modeling flexible Monitoring Systems with a Role-Based Control Loop", In Proceeding: COP 2022: International Workshop on Context-Oriented Programming and Advanced Modularity (collocated with ECOOP), ACM, Jun 2022. [doi]
Bibtex
@inproceedings{Shmelkin_Schutze_cop22,
doi = {10.1145/3570353.3570356},
url = {https://doi.org/10.1145%2F3570353.3570356},
year = 2022,
month = {jun},
publisher = ,
author = {Ilja Shmelkin and Lars Schütze and Tim Kluge},
title = {Modeling flexible Monitoring Systems with a Role-Based Control Loop},
booktitle = {{COP} 2022: International Workshop on Context-Oriented Programming and Advanced Modularity (collocated with {ECOOP})}
}Downloads
No Downloads available for this publication
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2021
- Nesrine Khouzami, Lars Schütze, Pietro Incardona, Landfried Kraaz, Tina Subic, Jeronimo Castrillon, Ivo F. Sbalzarini, "The OpenPME Problem Solving Environment for Numerical Simulations", In Proceeding: International Conference on Computational Science (ICCS'21) (Paszynski, Maciej and Kranzlmüller, Dieter and Krzhizhanovskaya, Valeria V. and Dongarra, Jack J. and Sloot, Peter M. A.), Springer International Publishing, pp. 614–627, Cham, Jun 2021. [doi] [Bibtex & Downloads]
The OpenPME Problem Solving Environment for Numerical Simulations
×Reference
Nesrine Khouzami, Lars Schütze, Pietro Incardona, Landfried Kraaz, Tina Subic, Jeronimo Castrillon, Ivo F. Sbalzarini, "The OpenPME Problem Solving Environment for Numerical Simulations", In Proceeding: International Conference on Computational Science (ICCS'21) (Paszynski, Maciej and Kranzlmüller, Dieter and Krzhizhanovskaya, Valeria V. and Dongarra, Jack J. and Sloot, Peter M. A.), Springer International Publishing, pp. 614–627, Cham, Jun 2021. [doi]
Abstract
We introduce OpenPME, the Open Particle-Mesh Environment, a problem solving environment that provides a Domain Specific Language (DSL) for numerical simulations in scientific computing. It is built atop a domain metamodel that is general enough to cover the main types of numerical simulations: simulations using particles, meshes, and hybrid combinations of particles and meshes. Using model-to-model transformations, OpenPME generates code against the state-of-the-art C++ parallel computing library OpenFPM. This effectively lowers the programming barrier and enables users to implement scalable simulation codes for high-performance computing (HPC) systems using high-level abstractions. Plenty of recent research has shown that higher-level abstractions and problem solving environments are well suited to alleviate low-level implementation overhead. We demonstrate this for OpenPME and its compiler on three different test cases—particle-based, mesh-based, and hybrid particle-mesh—showing up to 7-fold reduction in the number of lines of code compared to a direct OpenFPM implementation in C++.
Bibtex
@InProceedings{khouzami_iccs21,
author = {Nesrine Khouzami and Lars Sch{\"u}tze and Pietro Incardona and Landfried Kraaz and Tina Subic and Jeronimo Castrillon and Ivo F. Sbalzarini},
booktitle = {International Conference on Computational Science (ICCS'21)},
title = {The OpenPME Problem Solving Environment for Numerical Simulations},
doi = {10.1007/978-3-030-77961-0_49},
editor = {Paszynski, Maciej and Kranzlm{\"u}ller, Dieter and Krzhizhanovskaya, Valeria V. and Dongarra, Jack J. and Sloot, Peter M. A.},
isbn = {978-3-030-77961-0},
location = {Krakow (virtual), Poland},
organization = {Springer},
pages = {614--627},
publisher = {Springer International Publishing},
url = {https://link.springer.com/chapter/10.1007%2F978-3-030-77961-0_49},
abstract = {We introduce OpenPME, the Open Particle-Mesh Environment, a problem solving environment that provides a Domain Specific Language (DSL) for numerical simulations in scientific computing. It is built atop a domain metamodel that is general enough to cover the main types of numerical simulations: simulations using particles, meshes, and hybrid combinations of particles and meshes. Using model-to-model transformations, OpenPME generates code against the state-of-the-art C++ parallel computing library OpenFPM. This effectively lowers the programming barrier and enables users to implement scalable simulation codes for high-performance computing (HPC) systems using high-level abstractions. Plenty of recent research has shown that higher-level abstractions and problem solving environments are well suited to alleviate low-level implementation overhead. We demonstrate this for OpenPME and its compiler on three different test cases---particle-based, mesh-based, and hybrid particle-mesh---showing up to 7-fold reduction in the number of lines of code compared to a direct OpenFPM implementation in C++.},
address = {Cham},
month = jun,
numpages = {14},
year = {2021},
}Downloads
2106_Khouzami_ICCS [PDF]
Related Paths
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2020
- Lars Schütze, Jeronimo Castrillon, "Efficient Dispatch of Multi-Object Polymorphic Call Sites in Contextual Role-Oriented Programming Languages", Proceedings of the17th International Conference on Managed Programming Languages & Runtimes (MPLR'20), Association for Computing Machinery, pp. 52–62, New York, NY, USA, Nov 2020. [doi] [Bibtex & Downloads]
Efficient Dispatch of Multi-Object Polymorphic Call Sites in Contextual Role-Oriented Programming Languages
×Reference
Lars Schütze, Jeronimo Castrillon, "Efficient Dispatch of Multi-Object Polymorphic Call Sites in Contextual Role-Oriented Programming Languages", Proceedings of the17th International Conference on Managed Programming Languages & Runtimes (MPLR'20), Association for Computing Machinery, pp. 52–62, New York, NY, USA, Nov 2020. [doi]
Abstract
Adaptive software becomes more and more important as computing is increasingly context-dependent. Runtime adaptability can be achieved by dynamically selecting and applying context-specific code. Role-oriented programming has been proposed as a paradigm to enable runtime adaptive software by design. Roles change the objects’ behavior at runtime, thus adapting the software to a given context. The cost of adaptivity is however a high runtime overhead stemming from executing compositions of behavior-modifying code. It has been shown that the overhead can be reduced by optimizing dispatch plans at runtime for static cases, but no method exists to reduce the overhead in cases with high variability. This paper presents a novel approach to implement polymorphic role dispatch, taking advantage of dependent types and using run-time information to effectively guard abstractions and enable reuse. The concept of polymorphic inline caches is extended to role invocations. We evaluate the implementation with a benchmark for role-oriented programming languages achieving a geometric mean speedup of 4.0$\times$ (3.8$\times$ up to 4.5$\times$) in the static case, and close to no overhead in the dynamic case over the current implementation of contextual roles in Object Teams.
Bibtex
@InProceedings{schuetze_mplr20,
author = {Lars Sch{\"u}tze and Jeronimo Castrillon},
booktitle = {Proceedings of the17th International Conference on Managed Programming Languages \& Runtimes (MPLR'20)},
title = {Efficient Dispatch of Multi-Object Polymorphic Call Sites in Contextual Role-Oriented Programming Languages},
location = {Virtual, UK},
pages = {52--62},
numpages = {11},
series = {MPLR'20},
abstract = {Adaptive software becomes more and more important as computing is increasingly context-dependent. Runtime adaptability can be achieved by dynamically selecting and applying context-specific code. Role-oriented programming has been proposed as a paradigm to enable runtime adaptive software by design. Roles change the objects’ behavior at runtime, thus adapting the software to a given context. The cost of adaptivity is however a high runtime overhead stemming from executing compositions of behavior-modifying code. It has been shown that the overhead can be reduced by optimizing dispatch plans at runtime for static cases, but no method exists to reduce the overhead in cases with high variability. This paper presents a novel approach to implement polymorphic role dispatch, taking advantage of dependent types and using run-time information to effectively guard abstractions and enable reuse. The concept of polymorphic inline caches is extended to role invocations. We evaluate the implementation with a benchmark for role-oriented programming languages achieving a geometric mean speedup of 4.0$\times$ (3.8$\times$ up to 4.5$\times$) in the static case, and close to no overhead in the dynamic case over the current implementation of contextual roles in Object Teams.},
year = {2020},
month = nov,
numpages = {9},
isbn = {9781450388535},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3426182.3426186},
doi = {10.1145/3426182.3426186},
}Downloads
2010_Schuetze_MPLR [PDF]
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2019
- Lars Schütze, Jeronimo Castrillon, "Efficient Late Binding of Dynamic Function Compositions", Proceedings of the 12th ACM SIGPLAN International Conference on Software Language Engineering, ACM, pp. 141–151, New York, NY, USA, Oct 2019. [doi] [Bibtex & Downloads]
Efficient Late Binding of Dynamic Function Compositions
×Reference
Lars Schütze, Jeronimo Castrillon, "Efficient Late Binding of Dynamic Function Compositions", Proceedings of the 12th ACM SIGPLAN International Conference on Software Language Engineering, ACM, pp. 141–151, New York, NY, USA, Oct 2019. [doi]
Bibtex
@InProceedings{schuetze_sle19,
author = {Lars Sch{\"u}tze and Jeronimo Castrillon},
title = {Efficient Late Binding of Dynamic Function Compositions},
booktitle = {Proceedings of the 12th ACM SIGPLAN International Conference on Software Language Engineering},
year = {2019},
series = {SLE 2019},
address = {New York, NY, USA},
month = oct,
publisher = {ACM},
keywords = {conf},
location = {Athens, Greece},
isbn = {978-1-4503-6981-7},
pages = {141--151},
numpages = {11},
url = {http://doi.acm.org/10.1145/3357766.3359543},
doi = {10.1145/3357766.3359543},
acmid = {3359543},
}Downloads
1910_Schuetze_SLE [PDF]
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2017
- Lars Schütze, Jeronimo Castrillon, "Analyzing State-of-the-Art Role-based Programming Languages", Proceedings of the First International Conference on the Art, Science and Engineering of Programming (Programming'17), ACM, pp. 9:1–9:6, New York, NY, USA, Apr 2017. [doi] [Bibtex & Downloads]
Analyzing State-of-the-Art Role-based Programming Languages
×Reference
Lars Schütze, Jeronimo Castrillon, "Analyzing State-of-the-Art Role-based Programming Languages", Proceedings of the First International Conference on the Art, Science and Engineering of Programming (Programming'17), ACM, pp. 9:1–9:6, New York, NY, USA, Apr 2017. [doi]
Bibtex
@InProceedings{schuetze_lassy17,
author = {Lars Sch{\"u}tze and Jeronimo Castrillon},
title = {Analyzing State-of-the-Art Role-based Programming Languages},
booktitle = {Proceedings of the First International Conference on the Art, Science and Engineering of Programming (Programming'17)},
series = {Programming '17},
year = {2017},
month = apr,
isbn = {978-1-4503-4836-2},
location = {Brussels, Belgium},
pages = {9:1--9:6},
articleno = {9},
numpages = {6},
url = {http://doi.acm.org/10.1145/3079368.3079386},
doi = {10.1145/3079368.3079386},
acmid = {3079386},
publisher = {ACM},
address = {New York, NY, USA},
}Downloads
1704_Schuetze_lassy [PDF]
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