Summary

Deprecate thread_system monitoring interface types in favor of unified common::interfaces types.

This PR completes the thread_system portion of Phase 2, Task 2.3.

Changes

1. File-Level Deprecation Warning

Added comprehensive deprecation notice at the top of monitoring_interface.h:

• Clear warning that the file is deprecated
• Migration path to common::interfaces types
• Timeline: Deprecated 2025-10-02, Removal in v2.0.0
• Reference to common_system header

2. Namespace-Level Documentation

Added namespace deprecation with type mapping:

/**
 * @namespace monitoring_interface
 * @brief DEPRECATED: Thread-specific monitoring types
 *
 * Replacement mapping:
 * - monitoring_interface::thread_pool_metrics → common::interfaces::thread_pool_metrics
 * - monitoring_interface::worker_metrics → common::interfaces::worker_metrics
 * - monitoring_interface::system_metrics → common::interfaces::system_metrics
 * - monitoring_interface::monitoring_interface → common::interfaces::IMonitor
 */

3. Per-Type Deprecation Attributes

Marked all deprecated types with @deprecated tags:

• system_metrics
• thread_pool_metrics
• worker_metrics
• metrics_snapshot
• monitoring_interface (class)
• null_monitoring

Build Impact

Deprecation Warnings Visible

Compilation now shows warnings like:

warning: 'logger_interface' is deprecated: Use common::interfaces::ILogger instead

No Breaking Changes

• Existing code continues to work
• All tests pass
• Examples build successfully

Migration Guide

Before (thread_system-specific)

#include <kcenon/thread/interfaces/monitoring_interface.h>

monitoring_interface::thread_pool_metrics metrics;
metrics.jobs_completed = 100;
metrics.jobs_pending = 5;

After (unified common_system)

#include <kcenon/common/interfaces/monitoring_interface.h>

common::interfaces::thread_pool_metrics metrics;
metrics.jobs_completed.value = 100;
metrics.jobs_pending.value = 5;

Testing

• ✅ All unit tests pass (5/5 suites)
• ✅ All examples build successfully
• ✅ Deprecation warnings visible during compilation
• ✅ No functional regressions

Timeline

• Deprecated: 2025-10-02 (Phase 2)
• Removal: Version 2.0.0

Related PRs

• common_system: ci: Enable vcpkg binary caching with GitHub Actions cache #13 - Extend monitoring interface with typed metrics

Checklist

• All tests pass
• Examples build successfully
• Deprecation warnings added
• Migration guide documented
• Timeline specified
• No breaking changes

Phase 2 Progress

Task 2.3: Monitoring Interface Unification - Completed

Linked PR: #28 feat(phase2): deprecate monitoring interface types (Task 2.3)