#232 Fix race condition in concurrent approval scenarios#468
Merged
Xhristin3 merged 9 commits intorinafcode:mainfrom Apr 28, 2026
Merged
#232 Fix race condition in concurrent approval scenarios#468Xhristin3 merged 9 commits intorinafcode:mainfrom
Xhristin3 merged 9 commits intorinafcode:mainfrom
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Closes #232
Summary
This PR resolves the critical race condition in concurrent approval handling within the escrow system, preventing inconsistent state updates when multiple approvals occur simultaneously.
The fix improves data integrity by introducing proper synchronization during approval execution, adds concurrency-focused test coverage, and documents thread-safety guarantees for future maintainability.
Changes Made
contracts/teachlink/src/escrow_repository.rs
Synchronization Improvements
Implemented proper synchronization for approval state updates
Prevented multiple concurrent approvals from causing inconsistent escrow state
Ensured approval operations execute safely and atomically
State Integrity Protection
Added safeguards against duplicate approval processing
Prevented stale reads during concurrent approval execution
Improved validation flow to ensure only valid approval transitions occur
Concurrency Test Coverage
Added Concurrency Tests
Created comprehensive tests covering:
simultaneous approval attempts
duplicate approval prevention
state consistency after concurrent operations
approval threshold validation under concurrent execution
edge cases involving rapid sequential approval submissions
These tests ensure the repository behaves correctly under high-concurrency scenarios.
Documentation
Thread-Safety Guarantees
Added clear documentation covering:
approval synchronization strategy
atomic update guarantees
expected repository behavior during concurrent operations
assumptions and limitations around approval ordering
This improves long-term maintainability and helps contributors understand the concurrency model.
Acceptance Criteria Covered
✅ Implement proper synchronization
✅ Add concurrency tests
✅ Document thread-safety guarantees