Overview

Change thread_system from an optional to a required dependency in logger_system, removing standalone mode entirely.

Background

Currently, logger_system has an optional dependency on thread_system and supports standalone mode. This causes:

• Maintenance burden for two code paths
• Complexity from conditional compilation (#ifdef)
• Scattered test coverage

Since most higher-tier systems in unified_system already use thread_system, making it required has minimal practical impact.

Task List

Phase 1: CMake Cleanup (~1 hour)

• CMakeLists.txt: Remove LOGGER_STANDALONE_MODE option
• CMakeLists.txt: Make thread_system required (FATAL_ERROR if not found)
• cmake/LoggerDependencies.cmake: Remove fallback logic
• cmake/LoggerSystemConfig.cmake.in: Change to find_package(ThreadSystem REQUIRED)
• tests/CMakeLists.txt: Remove standalone conditions

Phase 2: Remove Conditional Compilation (~1 hour)

Macros to remove:

• LOGGER_STANDALONE
• LOGGER_STANDALONE_MODE
• USE_THREAD_SYSTEM (make always ON)

Header files to modify (8 files):

• include/kcenon/logger/core/thread_integration_detector.h
• include/kcenon/logger/backends/thread_system_backend.h
• include/kcenon/logger/writers/async_writer.h
• src/impl/di/di_container_factory.h
• src/impl/monitoring/monitoring_factory.h
• src/impl/monitoring/thread_system_monitor_adapter.h
• src/impl/di/thread_system_di_adapter.h
• src/impl/async/batch_processor.h

Phase 3: std::thread → worker_thread Migration (~2-3 hours)

Approach: Use dedicated worker_thread (long-running loops)

// Before
std::thread worker_thread_;
worker_thread_ = std::thread(&impl::process_loop, this);

// After
kcenon::thread::worker_thread worker_;
worker_.start([this]{ process_loop(); });

Source files to modify (3 files):

• src/core/log_collector.cpp (lines 111, 247)
• src/impl/writers/network_writer.cpp (lines 57, 61)
• src/impl/async/batch_processor.cpp (line 48)

Phase 4: Test Updates (~30 min)

• tests/integration/thread_system_integration_test.cpp: Remove GTEST_SKIP blocks
• Remove standalone-related test cases

Phase 5: Build Script Cleanup (~30 min)

• scripts/build.sh: Remove --standalone option

Phase 6: Verification (~1 hour)

• Full build succeeds
• Unit tests pass
• Integration tests pass
• CI/CD pipeline passes

Affected Files (19 total)

Dependency Change

Before:
  logger_system
    ├─ common_system (REQUIRED)
    └─ thread_system (OPTIONAL)

After:
  logger_system
    ├─ common_system (REQUIRED)
    └─ thread_system (REQUIRED)

Expected Benefits

• Reduced code complexity (~90% fewer conditional branches)
• Single code path for easier maintenance
• Simplified test coverage
• Access to thread_system optimizations (Lock-free Queue, Hazard Pointers, etc.)

Breaking Changes

• Standalone mode build no longer supported
• logger_system cannot be used without thread_system

Estimated Time

Approximately 5-6 hours