cog

9eb0b25c - fix: eliminate race condition in shutdown by setting gracefulShutdown flag earlier (#2628)

fix: eliminate race condition in shutdown by setting gracefulShutdown flag earlier (#2628) When shutdown was initiated, there was a race condition where new prediction requests could slip through before the gracefulShutdown flag was set, causing them to be rejected with 409 (Conflict) instead of 503 (Service Unavailable). The issue occurred because: 1. Service.Shutdown() closed the shutdown channel 2. A goroutine picked this up and called handler.Stop() 3. handler.Stop() set the gracefulShutdown flag 4. New predictions arriving during step 2-3 would pass the flag check The fix: - Extract flag-setting logic into handler.BeginShutdown() - Call BeginShutdown() immediately after shutdown signal, before Stop() - This ensures new predictions are rejected with 503 as soon as shutdown starts Fixes TestShutdownEndpointWaitsForInflightPredictions which was expecting 503 but receiving 409 due to this race condition. Co-authored-by: Mark Phelps <mphelps@cloudflare.com>