I have a reason to attempt this, tho I know I will implement my own lock if this approach works. In fact, I have to assume I cannot predict how will the $Deep grows, but the $Deep can be really deep, like JSON. Child threads will read files and then further extend the structure tree, and every other child will work depends on the current tree to dig what they interest. That's why I can't declare explicitly ahead, nor a clone of the current helps.

I could have a safer approach by using DB, or deploy a thread to implement a TCP socket, so every child talk to the DB/Socket, but I try to use at least of I/O as possible.