Tasklet

A tasklet is a bottom-half mechanism based on softirq, used to execute lightweight, non-sleepable callback logic within a softirq context.

Semantic Highlights

• Can be scheduled in hardirq/softirq/task context.
• Only one instance of the same tasklet can execute at a time (self-serializing).
• Repeated scheduling is deduplicated and will not enqueue indefinitely.
• Callbacks run in a softirq context, where sleeping is not allowed.

Data Passing

The tasklet callback is abstracted through the TaskletFunc trait, with an equivalent function signature:

fn(usize, Option<Arc<dyn TaskletData>>)

• usize is suitable for simple values or indices.
• Option``<Arc<dyn TaskletData>``> is suitable for complex data that requires safe sharing.

TaskletData is constrained to Send + Sync, and is safely shared via Arc to avoid passing raw pointers.