refactor: move goroutine out to function

tsdb/tsm1/engine.go

@@ -1135,32 +1135,8 @@ func (e *Engine) compactFull(ctx context.Context, grp CompactionGroup, wg *sync.
 			return false
 		}
 
-		done := make(chan struct{}) // Closed when compaction finished.
-		go func(lease influxdb.Lease) {
-			ttl, err := lease.TTL(ctx)
-			if err != nil {
-				e.logger.Warn("unable to get TTL for lease on semaphore", zap.Error(err))
-				ttl = influxdb.DefaultLeaseTTL // This is probably a reasonable fallback.
-			}
-
-			// Renew the lease when ttl is halved
-			ticker := time.NewTicker(ttl / 2)
-			for {
-				select {
-				case <-done:
-					if err := lease.Release(ctx); err != nil {
-						e.logger.Warn("Lease on sempahore was not released", zap.Error(err))
-					}
-					return
-				case <-ticker.C:
-					if err := lease.KeepAlive(ctx); err != nil {
-						e.logger.Warn("Unable to extend lease", zap.Error(err))
-					} else {
-						e.logger.Info("Extended lease on semaphore")
-					}
-				}
-			}
-		}(lease)
+		ctx, cancel := context.WithCancel(ctx)
+		go e.keepLeaseAlive(ctx, lease) // context cancelled when compaction finished.
 
 		e.compactionTracker.IncFullActive()
 		wg.Add(1)
@@ -1175,13 +1151,41 @@ func (e *Engine) compactFull(ctx context.Context, grp CompactionGroup, wg *sync.
 
 			// Release the files in the compaction plan
 			e.CompactionPlan.Release([]CompactionGroup{s.group})
-			close(done)
+			cancel()
 		}()
 		return true
 	}
 	return false
 }
 
+// keepLeaseAlive blocks, keeping a lease alive until the context is cancelled.
+func (e *Engine) keepLeaseAlive(ctx context.Context, lease influxdb.Lease) {
+	ttl, err := lease.TTL(ctx)
+	if err != nil {
+		e.logger.Warn("unable to get TTL for lease on semaphore", zap.Error(err))
+		ttl = influxdb.DefaultLeaseTTL // This is probably a reasonable fallback.
+	}
+
+	// Renew the lease when ttl is halved
+	ticker := time.NewTicker(ttl / 2)
+	for {
+		select {
+		case <-ctx.Done():
+			ticker.Stop()
+			if err := lease.Release(ctx); err != nil {
+				e.logger.Warn("Lease on sempahore was not released", zap.Error(err))
+			}
+			return
+		case <-ticker.C:
+			if err := lease.KeepAlive(ctx); err != nil {
+				e.logger.Warn("Unable to extend lease", zap.Error(err))
+			} else {
+				e.logger.Info("Extended lease on semaphore")
+			}
+		}
+	}
+}
+
 // compactionStrategy holds the details of what to do in a compaction.
 type compactionStrategy struct {
 	group CompactionGroup