1. IOA Code Generator (Making IOA Run)
January 2, 2019
IOA Code Generator (Making IOA Run)
Joshua A. Tauber
PODC Rump Session
July 17, 2000
Joint work with:
Steve Garland, Nancy Lynch, Michael Tsai I O A

2. What
Generate standard language (Java) translation of IOA program that will run in a physically distributed network
Execution should be efficient
No global synchronization

3. Why (Short term) Test bed for distributed algorithm design (Long term)
Find practical method for generating code from specifications

4. How Make humans do hard thinking
Model and use existing external services (e.g. network, console)
Use library of hand-written data type implementations
Stay in IOA until very last step
Successive refinement
Supports application of other tools

5. Node-Channel Form
Env
System
Global Specification
Node-Channel Form

6. Abstract Channels Abstract model for ease of programming
(e.g., Reliable FIFO queue):
Algorithm that implements abstract channel in terms of (model of) real channel:
Auxiliary Automaton
Real channel

7. Environment Implementation
Delay
Buffer
Console
Parser

8. Generated vs. External Automata
Env
Code to Generate
Algorithm
Channel

9. Code Generation Process
Submit IOA program for node algorithm
Generate parser automaton
Compose algorithm, parser (computed), and auxiliary network automata (from library)
Resolve nondeterminism in schedule
Convert implicit ND to explicit ND
Resolve explicit ND (programmer help)
Emit target language code
- Link to hand coded-datatype implementations

10. Truth in Advertising Assume network implements model
Assumes data type implementations implement axiomatic definitions
No current fault tolerance
Still in progess
Composer
Code generator
Proof of design correctness