[Python-ideas] easy thread-safety [was: fork]

[Steven D'Aprano]

On Thu, Aug 20, 2015 at 12:27:55PM -0400, Ron Adam wrote:

> When a bytecode to load an object is executed such as LOAD_FAST, it gets 
> it's reference to the object from the function's list of names in it's 
> code object.

Bytes codes are implementation, not semantics: there is no part of the 
Python language that promises that retrieving local variables will use a 
byte code LOAD_FAST. That's not how IronPython or Jython work, and there 
is no stability guarantee that CPython will always use LOAD_FAST. 


> LOAD_FAST 0,  reads __code__.co_varnames[0]
> LOAD_FAST 1,  reads __code__.co_varnames[1]
> 
> Adding a co_mutables name list to the __code__ attribute, along with new 
> bytecodes to access them, it would create a way to keep private local 
> names without changing how the other bytecodes work.
> 
> LOAD_MUTABLE 0,  would get the first reference in __code__.co_mutables.

What difference would it make to have a different implemention for 
retrieving and setting the object? How will having this byte code "keep 
private local names"?


-- 
Steve