> On 18 Jun 2020, at 18:42, Jonathan Fine <jfine2...@gmail.com> wrote: > > Hi Barry > > Thank you for your interest in my proposal. Let me try to answer your > question. You wrote: > > To make the code avoid COW you would need to be able to make sure that all > code memory blocks are not mixed in with PyObject memory blocks. > > Then the ref count dance will have trigger COW for the code. > > The relevant parts of my proposal are (emphasis added) > > When a Python function is called, the interpreter increases the refcount of > its code object. At the end of the function's execution, the interpreter > decreases the refcount. (An example below shows this.) > > **If Python were extended to take advantage of permanent code objects**, then > for example popular code objects could be loaded into memory in this way. > This can reduce memory usage (by sharing immutable resources) and reduce > startup time. > > I wanted this to mean that if the interpreter needs access to a permanent > code object, it simply accesses it, without changing any reference counts. > For this reason, permanent code objects don't need a refcount field. And > without that field, there is no refcount dance. > > The interpreter has privileged access to permanent code objects (just as it > has to its own internals, unless deliberately exposed). > > However, the code that is being interpreted has no such access. To enable > something like > >>> fn.__code__.co_code > b'whatever-the-bytecodes-are' > Python must have fn.__code__ return something that DOES have a refcount > field. It could be some sort of proxy object. Or it could be a 'transient > copy' of the permanent code object. > > I tried to explain this in the Appendix, perhaps not well enough. I hope this > helps.
Did my last reply cover a possible implementation of this? e.g. The code is nowhere near the ref-count that triggers COW. Barry > > -- > Jonathan
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