Blocker Module
Theblocker-module is the core enforcement infrastructure for the CommitT accountability platform. It utilizes an Android AccessibilityService to intercept application launches and user interactions in real-time.
Dual Enforcement Vectors
The service guarantees absolute enforcement via two complementary monitoring systems to prevent system-level evasion.- Event-Driven Enforcement: Responds instantly to
AccessibilityEventcallbacks to intercept restricted apps the precise millisecond they render. - Pulse-Based Background Audit: A continuous 5-second background heartbeat (
pulseRunnable) periodically re-evaluates the foreground package. This mitigates edge cases where the OS drops accessibility events (e.g., split-screen transitions, Picture-in-Picture mode).
Location Enforcement (Fail-Closed)
When a commitment includes a geofence, the Blocker maintains a real-time 1Hz GPS tracking stream.- Strict Live Enforcement: Spatial access decisions are gated exclusively on live coordinates. The service never defaults to cached
getLastKnownLocation()data, preventing spoofing via background disconnects. - Staleness Threshold: If a GPS fix is older than 30 seconds (accounting for Android’s 20-second background OS polling limitations), the Blocker defaults to a fail-closed policy, restricting access until cryptographic location certainty is restored.
Maximum Escalation (Device Lock & Purge)
If a user attempts a deep security violation (e.g., attempting to uninstall CommitT or disable the accessibility service), the Blocker initiates a Maximum Escalation sequence. On heavily modified OEM variants like Samsung’s OneUI, it executes a strict 3-Phase Purge:Concurrency and SQLite Stability
Identical to the Scheduler architecture, the Blocker explicitly opens its SQLite database connection inOPEN_READONLY mode. This prevents WAL writer contention against the React Native user interface. To eliminate stale reads, the connection is forcefully closed and a fresh WAL snapshot is acquired on every 5-second pulse.