task_timeline

Syntax

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

Available in

• File scope

Native C++

Unavailable in Native C++; select Lua for a file containing task_timeline.

Lifecycle

Ticks at a configurable frequency (default 10 Hz). Inside a bucket, wait, wait_until, operator prompts, and waiting DCode callback calls suspend only that bucket; mission time and other due buckets continue. Arbitrary blocking host calls still stall the tick. A tick that exceeds its configured period excludes that tick execution interval from subsequent mission time and shifts effective T0, rather than catching up through later buckets. Timing warnings remain enabled by default. A bucket’s scheduled clock hold freezes mission time and admission of later buckets while active buckets keep executing. Completion releases its scheduled hold unless an operator also holds the clock. The task _hold pauses execution and managed waits. Both holds retain timeline authority until explicit free or completed stop. The timeline stops once all buckets complete. An interrupted running timeline enters recovery and marks in-progress buckets uncertain on activation. Optional disable_warnings suppresses timing warnings while keeping measurements and callback errors.

Rules

• Require exactly one clock_start: T-1m or clock_t0: field, plus at least one at T…: runtime section.
• Signed T times accept a number followed by ms, s, m, or h (T-1m, T+30s) or an HH:MM:SS[.fraction] clock form (T+00:01:30). Bare 1m, T0, and at: T-1m are not bucket headers.
• Each bucket may have one hold_at: field at the same indentation as execute:. Use a signed T time at or after the bucket start, or next_bucket. The latter uses the next scheduled bucket after time ordering and requires a following bucket.
• A bucket can contain direct statements. If it declares any bucket-level hold:, resume:, stop:, or abort: section, it also requires execute: and all ordinary statements go inside that section.
• Timeline-level hold:, resume:, stop:, and abort: handlers are siblings of the at buckets. The same names inside a bucket are bucket-level handlers. Each optional handler is allowed once at its level.

Runtime sections

• at
• hold
• resume
• stop
• abort

Generated channels

• <name>_running
• <name>_hold
• <name>_clock_hold
• <name>_mission_time
• <name>_effective_t0
• <name>_clock_running
• <name>_aborted
• <name>_current_line
• <name>_target_frequency
• <name>_actual_frequency
• <name>_execution_time
• <name>_missed_cycles
• <name>_failed_cycles

Example

task_timeline timeline_name:
    clock_start: T-30m

    at T-20m (operation):
        hold_at: T-10m
        execute:
            command |task_running| = 1

Inputs

• name (required identifier): The timeline task name.
• frequency_hz (optional positive number): Timeline scheduler frequency in Hz; defaults to 10.
• priority (optional enum): background, normal (default), high, or critical. Supply frequency_hz first when setting priority.
• disable_warnings (optional flag): Suppress timing warnings while keeping measurements and callback errors.