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Annotations

Annotations in reactor-uc allow you to configure reactor components, specify platform details, and set up network communication. They refine system behavior and enable runtime optimizations across different hardware platforms.

Build Configuration

Configure how the reactor system is compiled and built.

  • @build_type("<type>")

    Specifies the build type for compilation optimization and debug symbols. This is only supported for the Native platform.

    Valid values:

    • "DEBUG": Include debug symbols and disable optimizations
    • "RELEASE": Enable optimizations and omit debug symbols

Runtime Configuration

Configure global runtime behavior and system-wide options.

  • @logging("<level>")

    Sets the logging verbosity level for the runtime system.

    Valid values:

    • "ERROR": Only log errors
    • "WARN": Log warnings and errors
    • "INFO": Log general information
    • "DEBUG": Log detailed debug information

  • @timeout(<time_value>)

    Specifies a global timeout for reactor execution. The program will shutdown after this amount of logical time.

    Parameters:

    • <time_value>: Logical time duration in appropriate time unit (e.g., MSEC(5000), SEC(5))

  • @fast(<boolean>)

    When enabled, the reactor system runs as fast as possible without waiting for physical time to advance. Useful for simulation and testing.

    Parameters:

    • <boolean>: true to enable fast execution, false for real-time execution

  • @keepalive(<boolean>)

    Controls whether the reactor keeps running when there are no more scheduled events. When disabled, the reactor may shut down prematurely.

    Parameters:

    • <boolean>: true to keep the reactor alive, false to allow shutdown

  • @clock_sync("<mode>")

    Globally enables or disables clock synchronization across a federation.

    Valid values:

    • "on": Enable clock synchronization
    • "off": Disable clock synchronization

Reactor Components

Annotations for configuring individual reactor components and connections.

  • @max_pending_event(<number>)

    Specifies the maximum number of elements that can be queued in a logical action's buffer. This controls memory usage and prevents unbounded growth of pending events.

    Parameters: - <number>: Maximum queue size (positive integer)

  • @buffer(<number>)

    Specifies the maximum number of elements that can be in transit across a delayed connection. Useful for controlling backpressure in pipelines.

    Parameters:

    • <number>: Maximum buffer size (positive integer)

Platform Configuration

Specify which platforms a federate should be compiled for in multi-platform federations.

  • @platform("<platform_name>")

    Generic platform annotation for specifying target platforms.

    Valid platforms: - "NATIVE": Native/Linux platform - "PICO": Raspberry Pi Pico - "ZEPHYR": Zephyr RTOS - "RIOT": RIOT OS - "FLEXPRET": FlexPRET - "PATMOS": Patmos hardware - "ESP-IDF": ESP-IDF framework - "FREERTOS": FreeRTOS

Warning

These annotations may be deprecated.

  • @platform_riot() - Compile for RIOT OS
  • @platform_zephyr() - Compile for Zephyr RTOS
  • @platform_patmos() - Compile for Patmos hardware
  • @platform_native() - Compile for native/Linux platform

Network Interfaces

Configure communication channels between federates using various network protocols.

  • @interface_tcp(name="string", address="127.0.0.1:4200")

    TCP/IP network interface for federate communication.

    Parameters: - name: Interface identifier - address: Host and port (format: "host:port")

  • @interface_uart(name="uart0", uart_device=0, baud_rate=115200, data_bits=8, parity="", stop_bits=1, async=false)

    UART/serial interface for embedded systems communication.

    Parameters:

    • name: Interface identifier
    • uart_device: Device number
    • baud_rate: Communication speed (e.g., 115200)
    • data_bits: Bits per character (typically 8)
    • parity: Parity mode (e.g., "", "even", "odd")
    • stop_bits: Stop bits (typically 1 or 2)
    • async: Whether to use asynchronous mode

  • @interface_coap(name="coap0", address="10.0.0.1")

    CoAP (Constrained Application Protocol) interface for IoT communication.

    Parameters:

    • name: Interface identifier
    • address: Server address

  • @interface_s4noc(core=0)

    S4NoC network-on-chip interface for tightly-coupled embedded systems.

    Parameters:

    • core: Core identifier

  • @interface_custom(name="c1", args="blabla", include="my_network.h")

    Custom network interface for user-defined communication protocols.

    Parameters:

    • name: Interface identifier
    • args: Custom arguments passed to the interface
    • include: Header file containing the interface implementation

Network Configuration

Configure how federates communicate across network interfaces.

  • @link(left="tcp0", right="tcp1")

    Specifies which network interfaces to use for transmitting values between federates. The left and right refer to previously defined interface names.

  • @maxwait(<time_value>)

    Maximum time a federate should wait for a value from a remote federate on a network channel. Helps prevent indefinite blocking in case of communication failures.

    Parameters: - <time_value>: Duration (e.g., MSEC(100), SEC(1))

  • @joining_policy(policy="<policy>")

    Controls how federates synchronize when joining a federation.

    Policies: - "TIMER_ALIGNED": Synchronize to a common time reference - "IMMEDIATELY": Begin execution immediately

Clock Synchronization

Configure distributed clock synchronization across federated systems.

  • @clock_sync(grandmaster=true, period=3500000000, max_adj=512000, kp=0.5, ki=0.1)

    Enable and configure clock synchronization using a PTP-like protocol for precise time alignment across federates.

    Parameters:

    • grandmaster: Whether this federate is the time reference (true/false)
    • period: Synchronization period in nanoseconds
    • max_adj: Maximum clock adjustment per sync cycle (nanoseconds)
    • kp: Proportional controller gain
    • ki: Integral controller gain

Legacy Annotations (Not Supported)

The following annotations are from earlier Lingua Franca versions and are not currently supported in reactor-uc:

  • @label()
  • @sparse()
  • @icon("value")
  • @side("value")
  • @layout(option="string", value="any") — e.g., @layout(option="port.side", value="WEST")
  • @enclave(each=boolean)
  • @property(name="<property_name>", tactic="<induction|bmc>", spec="<SMTL_spec>", CT=0, expect=true) - SMTL is the safety fragment of Metric Temporal Logic (MTL)
  • @_c_body
  • @_tpoLevel
  • @_networkReactor