feat: add advanced thread metrics (peak UPS, state transitions, queue depth, memory, jitter)

[buddhasaikia]

Summary

Closes #12

Adds five advanced thread metrics beyond basic update-count/avg-time tracking.

New Metrics

Metric	How it's computed
Peak Updates/Sec	1-second sliding window over update timestamps
State Transitions	Detects Thread.state changes between consecutive recordUpdate() calls
Queue Depth	Atomic counter incremented on channel.send(), decremented on receive
Memory	Debug.getNativeHeapAllocatedSize() (process-level; per-thread unavailable on Android)
Jitter	Standard deviation of inter-update intervals in milliseconds

Changes

Core (ThreadMetrics.kt)

• Extended ThreadMetrics data class with 5 new fields (all with defaults for backward compatibility)
• Added tracking structures in ThreadMonitor: updateTimestamps, stateTransitionCounts, lastThreadStates, queue depth atomic counter
• Implemented computePeakUpdatesPerSec(), computeJitter(), getThreadAllocatedBytes()
• Added incrementQueueDepth() / decrementQueueDepth() public methods

ViewModel (HomeViewModel.kt)

• Wired threadMonitor.incrementQueueDepth() after each channel.send() in all three fetch methods
• Wired threadMonitor.decrementQueueDepth() in initChannel on each receive

UI (HomeScreenRoute.kt)

• ThreadMetricsDisplay cards now show all 5 new metrics alongside existing ones

Export (MetricsExporter.kt)

• Added 5 new fields to ExportedThreadMetric
• Updated both buildCSVContent and buildJSONContent

Tests (ThreadMonitorTest.kt)

• 6 new tests: peak UPS, queue depth, jitter, memory, clear resets, default values
• Updated testThreadMetricsDataClass for new fields
• All existing tests continue to pass

Verification

BUILD SUCCESSFUL in 12s
33 actionable tasks: 11 executed, 22 up-to-date

[Copilot]

Pull request overview

This PR implements five advanced thread metrics to enhance the monitoring capabilities of the ThreadSimulator app: peak updates per second (using 1-second sliding window), thread state transitions, queue depth tracking, process-level memory allocation, and jitter measurements (standard deviation of inter-update intervals). The feature addresses issue #12 and extends the existing ThreadMetrics data class with backward-compatible default values while adding corresponding tracking structures in ThreadMonitor, UI display components, export functionality, and comprehensive unit tests.

Changes:

• Extended ThreadMetrics with 5 new fields, all with default values for backward compatibility
• Implemented tracking structures and computation methods in ThreadMonitor for advanced metrics
• Integrated queue depth tracking in HomeViewModel by adding increment/decrement calls around channel operations
• Updated UI to display all new metrics in ThreadMetricsDisplay cards with appropriate formatting
• Extended CSV and JSON export to include all new metric fields

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 14 comments.

Show a summary per file

File	Description
app/src/main/java/com/bs/threadsimulator/common/ThreadMetrics.kt	Added 5 new fields to ThreadMetrics data class, implemented tracking structures (updateTimestamps, stateTransitionCounts, lastThreadStates, queueDepthCounter), and computation methods (peak UPS, jitter, memory)
app/src/main/java/com/bs/threadsimulator/ui/screens/HomeViewModel.kt	Integrated queue depth tracking by calling incrementQueueDepth() after channel.send() and decrementQueueDepth() on receive
app/src/main/java/com/bs/threadsimulator/ui/screens/HomeScreenRoute.kt	Updated ThreadMetricsDisplay to show all 5 new metrics with formatting, increased card width to accommodate content
app/src/main/java/com/bs/threadsimulator/common/MetricsExporter.kt	Extended ExportedThreadMetric with new fields and updated buildCSVContent/buildJSONContent to export them
app/src/test/java/com/bs/threadsimulator/common/ThreadMonitorTest.kt	Added 6 new test cases for advanced metrics (peak UPS, queue depth, jitter, memory, clear resets, default values) and updated existing data class test