BLPOPBlocking left pop across one or more lists (effect logged as LPOP).
| 语法 | BLPOP key [key ...] timeout |
| 分组 | list |
| 参数个数 | -3 |
| 起始版本 | 1.0.0 |
| 标志 | write, blocking |
| 复杂度 | O(1) to serve; the park is O(1) and waiters are woken FIFO per key |
| Redis 兼容性 | differs: on a multi-shard server the multi-key form does not honour Redis's left-to-right key priority — keys on the connection's own shard are served before remote ones |