chore(ci): Add redis 8.4-RC1-pre & examples (#3572)

* add disable maintnotifications example

* add 8.4-RC1-pre

* println -> printf for linter

* address jit comment

Fix broken initialization of idle connections

optimize push notif

wip

wip

wip

wip

example/basic/main.go

@@ -0,0 +1,158 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+	"github.com/redis/go-redis/v9/maintnotifications"
+)
+
+func main() {
+	ctx := context.Background()
+	rdb := redis.NewClient(&redis.Options{
+		Addr:         ":6379",
+		Password:     "asdf",
+		Username:     "default",
+		MinIdleConns: 100,
+		MaintNotificationsConfig: &maintnotifications.Config{
+			Mode: maintnotifications.ModeDisabled,
+		},
+	})
+	commandRunner, stopCommandRunner := NewCommandRunner(rdb)
+	defer stopCommandRunner()
+	commandRunner.FireCommandsUntilStop(ctx)
+}
+
+type CommandRunnerStats struct {
+	Operations    int64
+	Errors        int64
+	TimeoutErrors int64
+	ErrorsList    []error
+}
+
+// CommandRunner provides utilities for running commands during tests
+type CommandRunner struct {
+	client         redis.UniversalClient
+	stopCh         chan struct{}
+	operationCount atomic.Int64
+	errorCount     atomic.Int64
+	timeoutErrors  atomic.Int64
+	errors         []error
+	errorsMutex    sync.Mutex
+}
+
+// NewCommandRunner creates a new command runner
+func NewCommandRunner(client redis.UniversalClient) (*CommandRunner, func()) {
+	stopCh := make(chan struct{})
+	cr := &CommandRunner{
+		client: client,
+		stopCh: stopCh,
+		errors: make([]error, 0),
+	}
+	return cr, cr.Stop
+}
+
+func (cr *CommandRunner) Stop() {
+	select {
+	case cr.stopCh <- struct{}{}:
+		close(cr.stopCh)
+		return
+	case <-time.After(500 * time.Millisecond):
+		return
+	}
+}
+
+func (cr *CommandRunner) Close() {
+	close(cr.stopCh)
+}
+
+// FireCommandsUntilStop runs commands continuously until stop signal
+func (cr *CommandRunner) FireCommandsUntilStop(ctx context.Context) {
+	fmt.Printf("[CR] Starting command runner...\n")
+	defer fmt.Printf("[CR] Command runner stopped\n")
+	// High frequency for timeout testing
+	ticker := time.NewTicker(100 * time.Millisecond)
+	defer ticker.Stop()
+
+	counter := 0
+	for {
+		select {
+		case <-cr.stopCh:
+			return
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			poolSize := cr.client.PoolStats().IdleConns
+			if poolSize == 0 {
+				poolSize = 1
+			}
+			wg := sync.WaitGroup{}
+			for i := 0; i < int(poolSize); i++ {
+				wg.Add(1)
+				go func(i int) {
+					defer wg.Done()
+					key := fmt.Sprintf("timeout-test-key-%d-%d", counter, i)
+					value := fmt.Sprintf("timeout-test-value-%d-%d", counter, i)
+
+					// Use a short timeout context for individual operations
+					opCtx, cancel := context.WithTimeout(ctx, 2*time.Second)
+					err := cr.client.Set(opCtx, key, value, time.Minute).Err()
+					cancel()
+
+					cr.operationCount.Add(1)
+					if err != nil {
+						if err == redis.ErrClosed || strings.Contains(err.Error(), "client is closed") {
+							select {
+							case <-cr.stopCh:
+								return
+							default:
+							}
+							return
+						}
+
+						fmt.Printf("Error: %v\n", err)
+						cr.errorCount.Add(1)
+
+						// Check if it's a timeout error
+						if isTimeoutError(err) {
+							cr.timeoutErrors.Add(1)
+						}
+
+						cr.errorsMutex.Lock()
+						cr.errors = append(cr.errors, err)
+						cr.errorsMutex.Unlock()
+					}
+				}(i)
+			}
+			wg.Wait()
+			counter++
+		}
+	}
+}
+
+func isTimeoutError(err error) bool {
+	return strings.Contains(err.Error(), "timeout")
+}
+
+// GetStats returns operation statistics
+func (cr *CommandRunner) GetStats() CommandRunnerStats {
+	cr.errorsMutex.Lock()
+	defer cr.errorsMutex.Unlock()
+
+	errorList := make([]error, len(cr.errors))
+	copy(errorList, cr.errors)
+
+	stats := CommandRunnerStats{
+		Operations:    cr.operationCount.Load(),
+		Errors:        cr.errorCount.Load(),
+		TimeoutErrors: cr.timeoutErrors.Load(),
+		ErrorsList:    errorList,
+	}
+
+	return stats
+}