Fix broken initialization of idle connections

Author: ndyakov

example/pubsub/go.mod renamed to example/maintnotifiations-pubsub/go.mod

@@ -699,20 +699,22 @@ func (cn *Conn) GetStateMachine() *ConnStateMachine {
 // TryAcquire attempts to acquire the connection for use.
 // This is an optimized inline method for the hot path (Get operation).
 //
-// It tries to transition from IDLE -> IN_USE or CREATED -> IN_USE.
+// It tries to transition from IDLE -> IN_USE or CREATED -> CREATED.
 // Returns true if the connection was successfully acquired, false otherwise.
+// The CREATED->CREATED is done so we can keep the state correct for later
+// initialization of the connection in initConn.
 //
 // Performance: This is faster than calling GetStateMachine() + TryTransitionFast()
 //
 // NOTE: We directly access cn.stateMachine.state here instead of using the state machine's
 // methods. This breaks encapsulation but is necessary for performance.
-// The IDLE->IN_USE and CREATED->IN_USE transitions don't need
+// The IDLE->IN_USE and CREATED->CREATED transitions don't need
 // waiter notification, and benchmarks show 1-3% improvement. If the state machine ever
 // needs to notify waiters on these transitions, update this to use TryTransitionFast().
 func (cn *Conn) TryAcquire() bool {
 	// The || operator short-circuits, so only 1 CAS in the common case
 	return cn.stateMachine.state.CompareAndSwap(uint32(StateIdle), uint32(StateInUse)) ||
-		cn.stateMachine.state.CompareAndSwap(uint32(StateCreated), uint32(StateInUse))
+		cn.stateMachine.state.CompareAndSwap(uint32(StateCreated), uint32(StateCreated))
 }
 
 // Release releases the connection back to the pool.

example/pubsub/go.sum renamed to example/maintnotifiations-pubsub/go.sum

@@ -319,6 +319,7 @@ func (cf *ClientFactory) Create(key string, options *CreateClientOptions) (redis
 	}
 
 	var client redis.UniversalClient
+	var opts interface{}
 
 	// Determine if this is a cluster configuration
 	if len(cf.config.Endpoints) > 1 || cf.isClusterEndpoint() {
@@ -349,6 +350,7 @@ func (cf *ClientFactory) Create(key string, options *CreateClientOptions) (redis
 			}
 		}
 
+		opts = clusterOptions
 		client = redis.NewClusterClient(clusterOptions)
 	} else {
 		// Create single client
@@ -379,9 +381,14 @@ func (cf *ClientFactory) Create(key string, options *CreateClientOptions) (redis
 			}
 		}
 
+		opts = clientOptions
 		client = redis.NewClient(clientOptions)
 	}
 
+	if err := client.Ping(context.Background()).Err(); err != nil {
+		return nil, fmt.Errorf("failed to connect to Redis: %w\nOptions: %+v", err, opts)
+	}
+
 	// Store the client
 	cf.clients[key] = client
 
@@ -832,7 +839,6 @@ func (m *TestDatabaseManager) DeleteDatabase(ctx context.Context) error {
 		return fmt.Errorf("failed to trigger database deletion: %w", err)
 	}
 
-
 	// Wait for deletion to complete
 	status, err := m.faultInjector.WaitForAction(ctx, resp.ActionID,
 		WithMaxWaitTime(2*time.Minute),