Reliability C# active http-service

Async request and service code does not block on tasks or fake async

rel-csharp-001

Intent

Prevent request-path thread starvation and deadlocks caused by blocking on async work or wrapping naturally async I/O in Task.Run.

Applicability

Applies to ASP.NET Core handlers, middleware, and service code that performs async I/O.

What to inspect

.Result, .Wait(), GetAwaiter().GetResult(), Task.Run around async I/O, synchronous form access, and legacy sync HTTP clients.

Pass criteria

Async work stays async end-to-end and request-path I/O uses naturally async APIs.

Fail criteria

The diff blocks on tasks, uses hidden sync-over-async APIs, or wraps async I/O in Task.Run.

Do not flag

Explicit CPU offload that is actually CPU-bound.

Confidence guidance

HIGH when sync-over-async is directly visible. MEDIUM when hidden blocking sits in a helper. LOW when runtime role is unclear.

Remediation

Await async APIs directly and keep blocking work off request threads.

Pass example

var form = await Request.ReadFormAsync(ct);

Fail example

var form = Request.Form;