task_periodic

Syntax

task_periodic <name> [frequency_hz] [priority] [disable_warnings]:

Available in

• File scope

Native C++

Compiles supported task logic to machine code. Fixed-channel reads and accepted writes occur at their executing lines. Prepared numeric operations and supported fixed collections can reuse storage; inline calculations and plugin code have their own costs. Neither the backend nor task priority guarantees a deadline.

Lifecycle

Activation creates the task and its channels; start runs once, task repeats while running, and end runs when stopped. Optional disable_warnings suppresses timing warnings while keeping measurements, skipped-cycle counts and callback errors.

Persistence

Ordinary runtime variables and state fields persist across lifecycle sections and iterations within a run. Each task start recreates working state; initialize it before reading, usually in start. File globals require an explicit global declaration and instead reset on file activation.

Reload behavior

DARTWIC tracks changes to the block and its template dependencies when loading the task.

Rules

• Frequency is positive Hz and defaults to 10. Priority is background, normal (default), high, or critical; supply a frequency before priority. The optional disable_warnings flag comes last.

Runtime sections

• start
• task
• missed
• end

Generated channels

• <name>_running
• <name>_target_frequency
• <name>_actual_frequency
• <name>_execution_time
• <name>_missed_cycles
• <name>_hold
• <name>_failed_cycles

Example

task_periodic task_name 100 background:
    start:
        -- setup

    task elapsed_seconds:
        local current = |channel|

    end:
        -- cleanup