It's not ideal, the api is kind of low-yet-high-level and that brings some complications.
Move backpressure handling onto the task producer and use a SharedArrayBuffer between the producer and worker, where the worker atomically updates a work-count or current work item ID in that SharedArrayBuffer that the producer can read (atomically) to determine how far along the worker has gotten.
Comments
It's not ideal, the api is kind of low-yet-high-level and that brings some complications.
Move backpressure handling onto the task producer and use a SharedArrayBuffer between the producer and worker, where the worker atomically updates a work-count or current work item ID in that SharedArrayBuffer that the producer can read (atomically) to determine how far along the worker has gotten.