Making closures sane (or attempting to)

[dktapps]

Closures are weirdly broken in pthreads in various ways.

The following restrictions must be imposed:

• [x] No use-by-reference. This currently silently breaks - the reference is turned into a regular value.
• [ ] No complex NTS uses. Currently, NTS types are silently removed, leading to code crashing when using used variables. This means that closure uses must be limited to the following:
  • Scalar
  • NULL
  • Threaded objects
  • Other valid closures
  • Sockets
• [x] No static variables. Static variables are impossible to make sane, since they can be altered after the closure is assigned to the Threaded object, making it impossible to verify their thread-safety. Therefore, local static variables must be prohibited entirely.
• [x] No NTS $this. Closure scope is currently silently obliterated when dereferenced on another thread, leading to crashes when a closure attempts to use $this.
• [x] Closures with a thread-safe $this (e.g. a ThreadedBase) must have their $this restored.

[dktapps]

I'm not sure this is even solvable with the static variables problem in mind.

[dktapps]

For some reason it did not occur to me to simply ban static variables in copied closures. Thank you @SOF3