# 4.2.9 ### 增强 * 新增 `Coroutine::defer` 方法 ### 修复 * 修复 max_connection 不能超过 10000 的bug([#2134](https://github.com/swoole/swoole-src/issues/2134 "#2134")) * 修复 Mysql客户端 执行`query CALL`查询后prepare 没清除buffer导致的错误([#2132](https://github.com/swoole/swoole-src/pull/2132 "#2132")) * 修复 MAXOS`sendfile`的 EAGAIN bug([60023b7](https://github.com/swoole/swoole-src/commit/60023b786c591d1a99eb857f9bbf827431945a75 "60023b7")) * 改善 `onReceive/onPacket` 的回调检查 * 使用 zend_fcall_info_cache * 删除 cidmap,cid将不会被再次重用 * 修复 socket construct failed core dump([02626d7](https://github.com/swoole/swoole-src/commit/02626d771643fa655f9c6cefbff049d5d23514ec "commit")) * 修复 进程等待waitpid bug([38753b4](https://github.com/swoole/swoole-src/commit/38753b4300704c03cb5cc5add2731ebf18972c34 "38753b4")) * 修复 swServer_signal_handler([#2145](https://github.com/swoole/swoole-src/issues/2145 "#2145")) * 修复 `Swoole\MsgQueue::destroy` 的拼写错误([28e4cd4](https://github.com/swoole/swoole-src/commit/28e4cd4041b2e638bea4fc1cee81869210e089df "28e4cd4")) * 修复 http2 header 太多导致的bug([5a1442a](https://github.com/swoole/swoole-src/commit/5a1442a56ff536182cfbd83db20ac256fd6ecb6f "5a1442a")) * 修复 hiredis 错误消息缓冲区溢出([2149](https://github.com/swoole/swoole-src/issues/2149 "2149"))