TruffleReloader: A Low-Overhead Language-Neutral Reloader

Transcript

1. TruffleReloader: A Low-Overhead Language- Neutral Reloader Tõnis Pool Allan Raundahl Gregersen Vesal Vojdani
2. Core Team Lead MSc student
3. Core Team Lead M.Sc student
4. Reloading - seeing the effects of source code changes immediately in a running application.
5. > Reloading Java via bytecode rewriting > 100+ integrations > Application servers > Frameworks > IDEs
6. Motivation > Thesis! > Usefulness - nice to have > Truffle seemed interesting
7. “Generic Reloading for Languages Based on the Truffle Framework” (link)
8. Truffle > Oracle Labs & Johannes Kepler University Linz > Reusing JVM runtime > Java API for AST interpreters > Language context > C, JavaScript, Ruby, Python, R, LLVM IR
9. Self-Optimizing AST Interpreters
10. def add(first, second): return first + second add(1, 1) U U U 1. read first 2. read second 3. add
11. U U I 1. read first 2. read second 3. add U I I 1. read first 2. read second 3. add
12. I I L 1. read first 2. read second 3. add I I I 1. read first 2. read second 3. add
13. Partial Evaluation
14. > Assume the tree is stable and compile AST (sub)tree to machine code > Deoptimize when assumptions invalidated
15. If and how the Truffle framework can help language implementers in adding reloading to their languages
16. Truffle Instrumentation API > Access to the execution state of Truffle interpreters > Wrapper nodes > Delegate to wrapped nodes > Fire events
17. TruffleReloader > Reusable reloading core > Low overhead > Java agent > -javaagent:/path/to/truffle-reloader.jar
18. Requirements for reloading 1. Detect source code changes 2. Source code parsing 3. Updating the execution tree
19. Proxy CallNode
21. # math.py def cos(x): ... def sin(x): ... # human_behaviour.py def socialize(x): ... def sin(x): ...
22. CallTarget Identity
23. CallTarget Identity > Globally unique > Stable
24. Partial AST Replay
26. TruffleReloader SPI
27. public interface LanguageReloader { String mimeType(); Supplier<CallTargetIdentity> getIdentityFor( RootCallTarget callTarget); ReplayController getReplayController(); default Predicate<String> acceptCodePath() { return (path) -> true; } }
28. public interface LanguageReloader { String mimeType(); Supplier<CallTargetIdentity> getIdentityFor( RootCallTarget callTarget); ReplayController getReplayController(); default Predicate<String> acceptCodePath() { return (path) -> true; } }
29. public interface LanguageReloader { String mimeType(); Supplier<CallTargetIdentity> getIdentityFor( RootCallTarget callTarget); ReplayController getReplayController(); default Predicate<String> acceptCodePath() { return (path) -> true; } }
30. public interface LanguageReloader { String mimeType(); Supplier<CallTargetIdentity> getIdentityFor( RootCallTarget callTarget); ReplayController getReplayController(); default Predicate<String> acceptCodePath() { return (path) -> true; } }
31. public interface LanguageReloader { String mimeType(); Supplier<CallTargetIdentity> getIdentityFor( RootCallTarget callTarget); ReplayController getReplayController(); default Predicate<String> acceptCodePath() { return (path) -> true; } }
32. public interface ReplayController<T extends ExecutionContext> { default void beforeStart(T context, Source source, Object[] currentArgs) {} default void afterStop(T context, Source source, Object[] currentArgs) {} boolean shouldStopAt( RootCallTarget executableCallTarget); }
33. public interface ReplayController<T extends ExecutionContext> { default void beforeStart(T context, Source source, Object[] currentArgs) {} default void afterStop(T context, Source source, Object[] currentArgs) {} boolean shouldStopAt( RootCallTarget executableCallTarget); }
34. public interface ReplayController<T extends ExecutionContext> { default void beforeStart(T context, Source source, Object[] currentArgs) {} default void afterStop(T context, Source source, Object[] currentArgs) {} boolean shouldStopAt( RootCallTarget executableCallTarget); }
35. Proxy CallNodes 1. Has the Source changed? 2. Are we running Partial AST Replay?
36. Proxy CallNodes 1. Has the Source changed? 2. Are we running Partial AST Replay? Guard the actions with Assumptions
37. public class SourceFileChecker { private static void run() { while (true) { wakeUp.await(CHECK_FREQUENCY, MILLISECONDS); sourceFiles.forEach((file, reloader) -> { long currentModified = file.lastModified(); if (map.get(file) != currentModified) { map.put(file, currentModified); reloader.invalidate(); } }); } } }
38. public class SourceFileChecker { private static void run() { while (true) { wakeUp.await(CHECK_FREQUENCY, MILLISECONDS); sourceFiles.forEach((file, reloader) -> { long currentModified = file.lastModified(); if (map.get(file) != currentModified) { map.put(file, currentModified); reloader.invalidate(); } }); } } }
39. public class SourceFileChecker { private static void run() { while (true) { wakeUp.await(CHECK_FREQUENCY, MILLISECONDS); sourceFiles.forEach((file, reloader) -> { long currentModified = file.lastModified(); if (map.get(file) != currentModified) { map.put(file, currentModified); reloader.invalidate(); } }); } } }
40. Evaluation > Graal.js, ZipPy, JRuby+Truffle and Simple Language > Functionality > Performance > https://github.com/poolik/bench9000 > Case Study
41. Functionality > Automated tests > Controlled via I/O
43. Use case SL ZipPy JRuby+Truffle Graal.js Changing a function y y y y Changing multiple functions y y y y Adding a new function y y y y Multiple consecutive reloads y y y y Changing global variable definition n/a y y y Adding a new global variable definition n/a y y y Reloading functions with same name n/a y y y Adding a new class n/a y y y Changing a static method n/a y y y Changing an instance method n/a y y y Adding a new instance method used from variable n/a y y y Adding a new instance method used from new object n/a y y y Adding a new instance method used from field n/a y y y Adding a new instance method used from global variable n/a y y y Multiple file reload, changing a method in dependency n/a y y n/a Multiple file reload, adding a new method in dependency n/a y y n/a Multiple file reload, changing an instance method in dependency on existing object n/a y y n/a Multiple file reload, changing an instance method in dependency on new object n/a y y n/a
45. iteration seconds
46. Case Study > Simple OSS Ruby web application > Fixed bugs & added features > https://github.com/poolik/sinatra_todo
47. > Changed method body > Added new method > Added new handler
49. TruffleReloader > Reusable reloading core > Ruby LanguageReloader ~ 80 LOC > Python LanguageReloader ~ 170 LOC > JS LanguageReloader ~ 160 LOC > Low overhead