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Scheduler Module

The scheduler-module serves as the primary orchestration engine of the CommitT native system. It bypasses the React Native layer entirely to calculate wake windows and explicitly command the Android Kernel’s AlarmManager to fire hardware-level wakeups.

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Architecture: Vault vs. Sticky Note

To survive unpredicted phone restarts and File-Based Encryption (FBE) lockouts, the Scheduler implements a dual-layered storage architecture.

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1. The Vault (SQLite)

The primary commit.db database. It holds the canonical schedule but is subject to strict Android Credential Encryption (CE). If a user restarts their device, this database remains completely locked and inaccessible at the kernel level until the user enters their PIN.

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2. The Sticky Note (Device Protected Storage)

To guarantee alarms fire even while the device is locked post-reboot, the Scheduler caches the 20 nearest upcoming alarms into Android’s Device Encrypted (DE) SharedPreferences. This unencrypted “Sticky Note” allows the BootReceiver to successfully schedule the AlarmManager before the user unlocks their phone.

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Connection Strategy & Concurrency Mitigations

The native Kotlin SQLite connection historically suffered from fatal Write-Ahead Logging (WAL) contention against the Javascript expo-sqlite driver. The Stale-Proof Formula:
  1. READONLY Mode: The AlarmScheduler strictly opens the database in OPEN_READONLY mode. This prevents it from holding a WAL writer lock. Previously, competing write locks on slow eMMC storage caused database disk image is malformed errors and infinite Nuke and Pave loops.
  2. Fresh Snapshots: The connection is opened and closed on every invocation of scheduleNextAlarm. Caching the connection resulted in “Stale WAL Snapshots,” where the Native side became permanently blind to tasks updated by the Javascript thread.

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The Pre-Alarm Math Engine

The findNextTrigger algorithm dynamically calculates staggered PRE_ALARM offsets, CHECKPOINT_ALARM structural pings, and the final END_ALARM.

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Hardware Kernel Registration

Once the closest actionable trigger is calculated, the Scheduler routes it directly to the Android AlarmManager:
  • Android 12+ (Exact): Utilizes setAlarmClock if exact permissions are granted, ensuring millisecond precision.
  • Degraded Fallback: Utilizes setAndAllowWhileIdle if the user revokes exact scheduling privileges, relying on OS-level batching.