Add additional example related to JobStuckHandler

example_job_stuck_handler_goroutine_dump_test.go

@@ -0,0 +1,47 @@
+package river_test
+
+import (
+	"context"
+	"log/slog"
+	"runtime"
+
+	"github.com/riverqueue/river"
+)
+
+// Example_jobStuckHandlerGoroutineDump demonstrates how to capture and log a
+// goroutine dump from a JobStuckHandler.
+func Example_jobStuckHandlerGoroutineDump() {
+	logger := slog.Default()
+
+	config := &river.Config{
+		JobStuckHandler: func(ctx context.Context, params river.JobStuckHandlerParams) river.JobStuckHandlerResult {
+			if logger.Enabled(ctx, slog.LevelWarn) {
+				logger.WarnContext(ctx, "River job stuck",
+					slog.Int64("job_id", params.ID),
+					slog.String("kind", params.Kind),
+					slog.String("queue", params.Queue),
+					slog.Int("total_stuck_jobs", params.TotalStuckJobs),
+					slog.String("goroutine_dump", captureGoroutineDump()),
+				)
+			}
+
+			return river.JobStuckHandlerResult{}
+		},
+	}
+
+	_ = config
+
+	// Output:
+}
+
+func captureGoroutineDump() string {
+	buf := make([]byte, 64*1024)
+	for {
+		n := runtime.Stack(buf, true)
+		if n < len(buf) {
+			return string(buf[:n])
+		}
+
+		buf = make([]byte, 2*len(buf))
+	}
+}