Metascala: a tiny DIY JVM
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Metascala is a tiny metacircular Java Virtual Machine (JVM) written in the Scala programming language. Metascala is barely 3000 lines of Scala, and is complete enough that it is able to interpret itself metacircularly. Being written in Scala and compiled to Java bytecode, the Metascala JVM requires a host JVM in order to run.
The goal of Metascala is to create a platform to experiment with the JVM: a 3000 line JVM written in Scala is probably much more approachable than the 1,000,000 lines of C/C++ which make up HotSpot, the standard implementation, and more amenable to implementing fun features like continuations, isolates or value classes. The 3000 lines of code gives you:
- The bytecode interpreter, together with all the run-time data structures
- A stack-machine to SSA register-machine bytecode translator
A custom heap, complete with a stop-the-world, copying garbage collector
Implementations of parts of the JVM's native interface
Although it is far from a complete implementation, Metascala already provides the ability to run untrusted bytecode securely (albeit slowly), since every operation which could potentially cause harm (including memory allocations and CPU usage) is virtualized and can be controlled. Ongoing work includes tightening of the security guarantees, improving compatibility and increasing performance.
Scala e xchange 2013 haoyi li on metascala a tiny diy jvm from Skills Matter.
YOU MAY ALSO LIKE:
- Bootstrapping the Scala.js Ecosystem (SkillsCast recorded in December 2014)
- Real World Kotlin Development Workshop (in London on 1st - 2nd July 2019)
- Pivotal's Core Spring (in London on 8th - 11th July 2019)
- Haskell eXchange 2019 (in London on 10th - 11th October 2019)
- Clojure eXchange 2019 (in London on 2nd - 3rd December 2019)
- Keynote by Dick Wall on Why API Design Matters, and Why Yours Sucks! (and mine sucks too!) (in London on 24th June 2019)
- London Java Community June (in London on 25th June 2019)
- The Elements of Tagless Final Style (SkillsCast recorded in May 2019)
- Scala 2.13 and Beyond! (SkillsCast recorded in April 2019)
Thanks to our sponsors
Metascala: a tiny DIY JVM
Haoyi Li
Haoyi is a recent MIT Graduate. He spent his years in college trying to build websites, and wondered why it always felt like bashing your head against a brick wall.
Please log in to watch this conference skillscast.
Metascala is a tiny metacircular Java Virtual Machine (JVM) written in the Scala programming language. Metascala is barely 3000 lines of Scala, and is complete enough that it is able to interpret itself metacircularly. Being written in Scala and compiled to Java bytecode, the Metascala JVM requires a host JVM in order to run.
The goal of Metascala is to create a platform to experiment with the JVM: a 3000 line JVM written in Scala is probably much more approachable than the 1,000,000 lines of C/C++ which make up HotSpot, the standard implementation, and more amenable to implementing fun features like continuations, isolates or value classes. The 3000 lines of code gives you:
- The bytecode interpreter, together with all the run-time data structures
- A stack-machine to SSA register-machine bytecode translator
A custom heap, complete with a stop-the-world, copying garbage collector
Implementations of parts of the JVM's native interface
Although it is far from a complete implementation, Metascala already provides the ability to run untrusted bytecode securely (albeit slowly), since every operation which could potentially cause harm (including memory allocations and CPU usage) is virtualized and can be controlled. Ongoing work includes tightening of the security guarantees, improving compatibility and increasing performance.
Scala e xchange 2013 haoyi li on metascala a tiny diy jvm from Skills Matter.
YOU MAY ALSO LIKE:
- Bootstrapping the Scala.js Ecosystem (SkillsCast recorded in December 2014)
- Real World Kotlin Development Workshop (in London on 1st - 2nd July 2019)
- Pivotal's Core Spring (in London on 8th - 11th July 2019)
- Haskell eXchange 2019 (in London on 10th - 11th October 2019)
- Clojure eXchange 2019 (in London on 2nd - 3rd December 2019)
- Keynote by Dick Wall on Why API Design Matters, and Why Yours Sucks! (and mine sucks too!) (in London on 24th June 2019)
- London Java Community June (in London on 25th June 2019)
- The Elements of Tagless Final Style (SkillsCast recorded in May 2019)
- Scala 2.13 and Beyond! (SkillsCast recorded in April 2019)
Thanks to our sponsors
Metascala: a tiny DIY JVM
Haoyi Li
Haoyi is a recent MIT Graduate. He spent his years in college trying to build websites, and wondered why it always felt like bashing your head against a brick wall.