Job Cancellation

Warp uses a CancellationMode enum for graceful job cancellation. When you cancel a processing job, it doesn't immediately change state — the handler gets a chance to stop cleanly.

How It Works

1. Cancel request: DeleteJob(id) on a processing job sets CancellationMode = Graceful. The job stays in Processing state.
2. Worker detects: RunJobMonitor polls every CancellationCheckInterval (default 5s). When it sees CancellationMode != None, it cancels the handler's CancellationToken.
3. Handler responds: If the handler respects the token, it throws OperationCanceledException. The worker catches it and sets the job to Deleted.
4. Handler ignores: If the handler completes despite cancellation, the job is marked Completed — the work happened, and that's the truth.

DeleteJob(processingJobId)
  → CancellationMode = Graceful (state stays Processing)
  → RunJobMonitor detects CancellationMode
  → Handler's CancellationToken cancelled
  → Handler stops → state = Deleted, ExpireAt set
  → Handler finishes anyway → state = Completed

Dashboard

Processing jobs with CancellationMode = Graceful show a "Cancelling..." badge in orange instead of the normal "Processing" badge. This is visible in both the job list and job detail pages.

The job remains in the Processing tab until the handler actually exits — the dashboard shows the truth about what the worker is doing.

Writing Cancellable Handlers

Always check CancellationToken in long-running handlers:

public class LongRunningHandler : IJobHandler<LongRunningRequest>
{
    public async Task HandleAsync(LongRunningRequest message, CancellationToken ct)
    {
        foreach (var item in items)
        {
            ct.ThrowIfCancellationRequested();
            await ProcessItem(item);
        }
    }
}

If your handler ignores the token, cancellation still works — but the handler runs to completion and the job is marked Completed, not Deleted.

Cancelling a Batch

CancelBatch(batchId) cancels a whole batch in one call (surfaced as a Cancel action on the batch detail page). It is transitive: it walks the ParentJobId tree breadth-first from the batch and gracefully cancels every non-terminal descendant — not just the direct children, but also pending continuations reached through children that have already finished. Jobs already in a terminal state (Completed, Failed, Deleted) are left untouched, so cancelling a mostly-finished batch only affects the work still outstanding.

Each cancelled job follows the same graceful path as a single DeleteJob: CancellationMode = Graceful, the handler's token is cancelled on the next monitor tick, and the job settles to Deleted once the handler exits (or Completed if it ignores the token and finishes). Passing a non-batch id throws ArgumentException.

CancellationMode Enum

Value	Description
None (0)	No cancellation requested
Graceful (1)	Cancel token, wait for handler to exit

The enum is designed for future extension (e.g., Force for thread abort).