Back to the Future in One Week — Implementing a Smalltalk VM in PyPy
We report on our experiences with the Spy project, including implementation details and benchmark results. Spy is a re-implementation of the Squeak (i.e. Smalltalk-80) VM using the PyPy toolchain. The PyPy project allows code written in RPython, a subset of Python, to be translated to a multitude of different backends and architectures. During the translation, many aspects of the implementation can be independently tuned, such as the garbage collection algorithm or threading implementation. In this way, a whole host of interpreters can be derived from one abstract interpreter definition. Spy aims to bring these benefits to Squeak, allowing for greater portability and, eventually, improved performance. The current Spy codebase is able to run a small set of benchmarks that demonstrate performance superior to many similar Smalltalk VMs, but which still run slower than in Squeak itself. Spy was built from scratch over the course of a week during a joint Squeak-PyPy Sprint in Bern last autumn.
KeywordsVirtual Machine Garbage Collection Java Virtual Machine Blue Book Memory Layout
Unable to display preview. Download preview PDF.
- 1.Bolz, C.F., Rigo, A.: Memory management and threading models as translation aspects – solutions and challenges. Technical report, PyPy Consortium (2005), http://codespeak.net/pypy/dist/pypy/doc/index-report.html
- 2.Denker, M.: Entwurf von optimierungen für squeak, Studienarbeit, Universität Karlsruhe (2002)Google Scholar
- 4.Ingalls, D., Kaehler, T., Maloney, J., Wallace, S., Kay, A.: Back to the future: The story of Squeak, a practical Smalltalk written in itself. In: Proceedings of the 12th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (OOPSLA 1997), pp. 318–326. ACM Press, New York (1997)CrossRefGoogle Scholar
- 5.Lattner, C., Adve, V.: LLVM: A Compilation Framework for Lifelong Program Analysis & Transformation. In: Proceedings of the 2004 International Symposium on Code Generation and Optimization (CGO 2004) (March 2004)Google Scholar
- 6.Pedroni, S., Rigo, A.: JIT compiler architecture. Technical report, PyPy Consortium (2007), http://codespeak.net/pypy/dist/pypy/doc/index-report.html
- 7.Rigo, A., Hudson, M., Pedroni, S.: Compiling dynamic language implementations. Technical report, PyPy Consortium (2005), http://codespeak.net/pypy/dist/pypy/doc/index-report.html
- 8.Rigo, A., Pedroni, S.: PyPy’s approach to virtual machine construction. In: Proceedings of the 2006 conference on Dynamic languages symposium, OOPSLA 2006: Companion to the 21st ACM SIGPLAN conference on Object-oriented programming systems, languages, and applications, pp. 944–953. ACM Press, New York (2006)Google Scholar