PHP 子进程开发中连接数据库报错。子进程不能共用父进程的连接？

感觉是子进程不能共用父进程的数据库连接。
有没有人遇到这样的问题。

疑问一：我快速执行的时候就能正常执行，即正常连接，很神奇的。
疑问二：主进程还在，数据库连接应该还不注销的吧

PHP Fatal error:  Uncaught ErrorException: Packets out of order. Expected 1 received 102. Packet size=6644739 in /var/www/vdb1/app/test_trader/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php:61
Stack trace:
#0 [internal function]: Illuminate\Foundation\Bootstrap\HandleExceptions->handleError(2, 'Packets out of ...', '/var/www/vdb1/a...', 61, Array)
#1 /var/www/vdb1/app/test_trader/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php(61): PDO->prepare('select * from `...', Array)
#2 /var/www/vdb1/app/test_trader/vendor/laravel/framework/src/Illuminate/Database/Connection.php(326): Doctrine\DBAL\Driver\PDOConnection->prepare('select * from `...')
#3 /var/www/vdb1/app/test_trader/vendor/laravel/framework/src/Illuminate/Database/Connection.php(657): Illuminate\Database\Connection->Illuminate\Database\{closure}('select * from `...', Array)
#4 /var/www/vdb1/app/test_trader/vendor/laravel/framework/src/Illuminate/Database/Connection.php(624): Illuminate\Database\Connection->runQueryCallback('select * from ` in /var/www/vdb1/app/test_trader/vendor/laravel/framework/src/Illuminate/Database/Connection.php on line 664