1. Automatic Derivation, Integration, and Verification of Synchronization Aspects in Object-Oriented Design Methods Automatic Derivation, Integration, and Verification of Synchronization Aspects in Object-Oriented Design Methods DARPA Order K203/AFRL Contract F33615-00-C-3044 Principal Investigators Matt Dwyer John Hatcliff Masaaki Mizuno Mitch Neilsen Gurdip Singh Department of Computing and Information Sciences Kansas State University http://www.cis.ksu.edu/santos

2. Problem Description Embedded systems are growing in complexity and developers are looking towards OO technologies to manage that complexity Design methods for OO do not treat synchronization effectively Embedded systems software is multi-threaded for performance reasons –System correctness relies on correct synchronization of multiple activities Synchronization design/implementation is low-level and platform specific –Error prone and not reusable

3. Project Objectives III. Automatic verification of critical safety and liveness properties of woven embedded code … domain-specific model-checking engines … built on previous DARPA work – Bandera environment II. Automatic derivation and weaving of synchronization code … multiple language and synchronization targets (Java, C++, monitors, semaphores, etc.) … weaving & optimization via abstract interpretation and program specialization techniques I. Provide high-level, modular specification of global synchronization aspects … integrated with UML/RUP … formal specification via global invariants … language of composable invariant patterns … powerful, yet easy to use IV. Evaluation using Common Digital Architecture (CDA 101) … a new standard for military target vehicle electronics

4. Complete Program Technical Approach/Accomplishments Actors: Use Cases Classes: Use-Case Realizations Component Code Synchronization specifications –via invariants –Identify common idioms/patterns Global Invariant Specs Coarse-Grain Solution Automated coarse-grain generation –SVC and pattern-based Prototype release 9/01 Fine-Grain Synchronization Code Complete Program Synch-code generators –C/C++ and Java –Monitor, Semaphore, … Complete Program Rational Unified Process (RUP)

5. Technical Approach --- Specifications Users never write raw invariants but instead build synchronization specifications using a collection of global invariant patterns (idioms)… Bound(R,n) … at most n threads can be in region R Exclusion(R1,R2) … occupancy of region R1 and R2 should be mutually exclusive Resource(R1, R2, n) … region R1 is a producer, region R2 is a consumer of some resource with n initial resource values. Barrier(R1,R2) … the k th thread to enter R1 and the k th thread to enter R2 meet and leave their respective regions together …

6. Contribution to PCES Goals Invariant patterns enable reuse of synchronization “solutions” across multiple systems and languages –Evaluate reduction in effort in the context of OEPs on existing applications, if suitable code/design history is available on controlled system development (class projects) Synthesis of “correct” synchronization implementations potentially eliminates a class of subtle coding errors –Evaluate potential for reducing errors and validation effort as above The overarching goal of the PCES program is novel technology and supporting engineering approaches that can greatly reduce effort to program embedded systems, while increasing confidence in the embedded software product.

7. Contribution to Relevant Military Application Apply our approach to CDA 101 based systems –CDA 101 provides a common architecture for networking target vehicle electronics using CAN –Extract synchronization regions from existing applications and re-engineer using our approach DoD Target System Studies –Seaborne (ST 2000) and Airborne (BQM-74, MQM-107) CDA 101 and NMEA 2000 co-evolving standards –NMEA 2000 working group member –Regular interaction with and source-code from Seaborne Targets Engineering Group (NAWC – Point Mugu, CA)

8. Project Tasks/Schedule Integration Verification Code weaver Aspect code synthesis Synch Aspect language Key Tasks Non-synch Aspects Initial Optimized Full-scale Evaluation 5/01 5/02 11/01 11/01 + 5/02 11/01 + 5/02 + 5/03 5/02 + 5/03

9. Collaborations Stanford (SVC) Berkeley (Bane) MIT (analyses to optimize weaved code) Grammatech, Inc. (slicing/verification techniques) Collins, aJile systems (JEM boards) Honeywell (challenge problems from avionics) Kvaser, AB (CAN Kingdom = CDA 101/11) Seaborne Targets Engineering Lab (CDA 101) National Marine Electronics Association (NMEA)

10. Technology Transition/Transfer CDA 101 based Target Systems –Seaborne Targets: ST 2000 –Airborne Targets: BQM-74 MQM-107 Commercial Applications –NMEA 2000, CanKingdom - standards for real- time networking –Precision farming, industrial automation

11. Program Issues Difficult to do long range planning when there is a sense that funding is in jeopardy Program meetings provide little time for technical interchange –i.e., identifying future collaborators Involvement of more industrial participants to provide challenge problems –i.e., need more than code and documentation Limited equipment availability restricts full deployment of prototypes

12. Synchronization Regions Use-Case Actor Use-Case Actor System Classes/Objects Use-case Realizations Wait WakeUp Wait WakeUp

13. Synchronization Patterns (excerpts) R n In Out R_1 In_1 Out_1 R_2 In_2 Out_2 Bound(R, n) Barrier(R_1,R_2) BarrierWithInfoEx(R_1,R_2) Relay(R_1,R_2) 8 basic patterns in current collection (many more composite patterns) Pattern compositions can solve all synchronization problems in Andrew’s and Hartley’s books We welcome challenge problems from PCES participants

14. Multiple Target Detectors and a Single Firing Battery Use-case realizations B1. Wait until a detector locks on a target B2. Receive information from the detector and fire B3. Release the detector T1. Lock on a target T2. Wait until the battery is available T3. Send information to the battery T4. Wait until released

15. Multiple Target Detectors and a Single Firing Battery Use-case realizations B1. Wait until a detector locks on a target B2. Receive information from the detector and fire B3. Release the detector T1. Lock on a target T2. Wait until the battery is available T3. Send information to the battery T4. Wait until released

16. R_B3 R_T4 B3 T4 R_B1 R_T2 B1 B2 T3 T2 T1 Communicate Patterns for Target System R_F Fire Relay(R_B3, R_T4) Barrier(R_B1, R_T2) Bound(R_F,1) BarrierWithInfoEx( R_B1, R_T2) Relay(R_B3, R_T4)

17. Next Milestones (6-9-12 months) Extend synthesis approach to distributed CAN-based systems including CanKingdom and CDA 101 Public distribution of prototype synchronization specification, code generation, and weaving tools Generate solutions to other synchronization problems from CDA 101, Industrial Automation (KTEC) and Agricultural (John Deere) applications Extend global invariant approach to address real-time synchronization properties (e.g., priority inversion) Integrate Bandera to check safety/liveness properties

18. Funding Profile and Financial Expenditures to Date We are burning our Salary/IDC at 100% –Due to a clerical error certain charges made against the project have not hit the project account –It may appear that we are underspending, but back-charges will hit within the next month. We are burning our travel money at ~80% –Travel money from the 1 st funding period was shifted to the second period. This means that 100% burn of the second period’s travel money will appear as if we are underburning. –Note that due to this shift we had to pay for travel to the PCES kickoff meeting from non-PCES sources.

19. Technical Approach --- Tool Architecture UML Tools Synchronization Aspect Specification Tool Intermediate Representation Generator Solver/ Prover Course-grain solution Synchronization Aspect Back-end Bandera Analysis & Transformation Fine-grain solution Specialization Engine Bandera Safety Properties Liveness Properties Code Weaver Optimized Woven Code Invariant & Region tags Functional Core Code Templates (Java, C++, …) Template Instantiation Traditional Development Environment Functional Core Code (Java, C++, …) Finite State Models

20. Seaborne Target 2000 (ST 2000)