A little bit of optimization in periodicallyPurge()

Fixed panjf2000#45 and Releasing v2 module

Fixed panjf2000#45 and Releasing v2 module

support nonblocking submit and max blocking limit setting

Signed-off-by: Cholerae Hu <[email protected]>

🎏Fix a bug where invokers get stuck in waiting idle workers

🧸Remove useless test cases

📝Fix the type error

🙄 Improvement in `periodicallyPurge`