php中redis的exec的用法是什么

redis 127.0.0.1:6379> Exec

# 事务被成功执行
redis 127.0.0.1:6379> MULTI
OK
redis 127.0.0.1:6379> INCR user_id
QUEUED
redis 127.0.0.1:6379> INCR user_id
QUEUED
redis 127.0.0.1:6379> INCR user_id
QUEUED
redis 127.0.0.1:6379> PING
QUEUED
redis 127.0.0.1:6379> EXEC
1) (integer) 1
2) (integer) 2
3) (integer) 3
4) PONG
# 监视 key ，且事务成功执行
redis 127.0.0.1:6379> WATCH lock lock_times
OK
redis 127.0.0.1:6379> MULTI
OK
redis 127.0.0.1:6379> SET lock "huangz"
QUEUED
redis 127.0.0.1:6379> INCR lock_times
QUEUED
redis 127.0.0.1:6379> EXEC
1) OK
2) (integer) 1
# 监视 key ，且事务被打断
redis 127.0.0.1:6379> WATCH lock lock_times
OK
redis 127.0.0.1:6379> MULTI
OK
redis 127.0.0.1:6379> SET lock "joe"        # 就在这时，另一个客户端修改了 lock_times 的值
QUEUED
redis 127.0.0.1:6379> INCR lock_times
QUEUED
redis 127.0.0.1:6379> EXEC                  # 因为 lock_times 被修改， joe 的事务执行失败
(nil)