GeezerVison

sequenceDiagram
    participant CMake as CMake Build System
    participant Config as config.h
    participant Daemon as Netdata Daemon
    participant Signal as Signal Handler
    participant Log as Log System
    participant StatusFile as Status File Manager
    participant Stacktrace as Stacktrace Module
    participant Backend as Stacktrace Backend

    Note over CMake,Backend: Build-time Configuration Flow

    CMake->>CMake: Check OS platform
    alt Non-FreeBSD (Linux, macOS, etc.)
        CMake->>CMake: Compile stacktrace sources
        CMake->>CMake: Set HAVE_STACKTRACE=True
    else FreeBSD
        CMake->>CMake: Skip stacktrace sources
        CMake->>CMake: HAVE_STACKTRACE not set
    end
    CMake->>Config: Export HAVE_STACKTRACE macro
    Config-->>Daemon: Compile-time define available

    Note over Daemon,Backend: Runtime Initialization Flow

    Daemon->>Log: Initialize logging system
    Log->>Stacktrace: stacktrace_init()
    alt HAVE_STACKTRACE defined
        Stacktrace->>Backend: Initialize backend
        Backend-->>Stacktrace: Backend ready
        Stacktrace-->>Log: Init complete
    else HAVE_STACKTRACE undefined
        Stacktrace-->>Log: Skip init
    end

    Daemon->>Signal: Initialize signal handlers
    Signal->>Stacktrace: Set signal handler name
    alt HAVE_STACKTRACE defined
        Stacktrace-->>Signal: Handler name registered
    end

    Note over Daemon,StatusFile: Deadly Signal Flow

    Daemon->>Signal: Receive deadly signal (SIGSEGV, etc.)
    Signal->>StatusFile: Record deadly signal
    StatusFile->>Stacktrace: Check availability
    alt HAVE_STACKTRACE defined AND stacktrace_available()
        StatusFile->>Stacktrace: Capture stack trace
        Stacktrace->>Backend: Get stack trace data
        Backend-->>Stacktrace: Raw stack frames
        Stacktrace-->>StatusFile: Stack trace content
        StatusFile->>StatusFile: Save status file with exit reason + signal code + stack trace
    else HAVE_STACKTRACE undefined OR unavailable
        StatusFile->>StatusFile: Save status file without stack trace info
    end
    StatusFile-->>Daemon: Status persisted

    Note over Daemon,Stacktrace: Unittest Flow (-W stacktracetest)

    Daemon->>Stacktrace: stacktrace_unittest()
    Stacktrace->>Stacktrace: Initialize subsystem
    Stacktrace->>Backend: Check capture capability
    alt Backend cannot capture stack traces
        Stacktrace-->>Daemon: Test SKIPPED (return 0)
    else Backend can capture
        Stacktrace->>Stacktrace: Run cache collision tests
        Stacktrace-->>Daemon: Test results
    end

    Note over Daemon,Backend: Daemonize Flow

    Daemon->>Daemon: become_daemon()
    alt HAVE_STACKTRACE defined
        Daemon->>Stacktrace: stacktrace_flush()
        Stacktrace->>Backend: Flush cached data
        Backend-->>Stacktrace: Flush complete
        Stacktrace-->>Daemon: Ready for child process
    end