Function default_backlog 

pub fn default_backlog() -> i32

The default listen backlog: the system’s maximum accept queue. On Linux that is /proc/sys/net/core/somaxconn (read once), capped at 65535, or 4096 if it can’t be read; on Windows SOMAXCONN (the provider’s maximum); elsewhere 65535, which the kernel clamps to its own somaxconn.