Commit graph

3 commits

Author SHA1 Message Date
8de3fe21bb Chain-Load: detect small-object optimisation
- Helper function to find out of two objects are located
  "close to each other" -- which can be used as heuristics
  to distinguish heap vs. stack storage

- further investigation shows that libstdc++ applies the
  small-object optimisation for functor up to »two slots«
  in size -- but only if the copy-ctor is trivial. Thus
  a lambda capturing a shared_ptr by value will *always*
  be maintained in heap storage (and LazyInit must be
  redesigned accordingly)...

- the verify_inlineStorage() unit test will now trigger
  if some implementation does not apply small-object optimisation
  under these minimal assumptions
2023-12-03 04:59:18 +01:00
3c713a4739 Chain-Load: invent the heart of the trap-mechanism
...the intention is to plant a »trojan lambda« into the target functor,
to set off initialisation (and possibly relocation) on demand.
2023-12-03 04:59:18 +01:00
1892d1beb5 Chain-Load: safety problems with rule initialisation
the RandomDraw rules developed last days are meant to be used
with user-provided λ-adapters; employing these in a context
of a DSL runs danger of producing dangling references.

Attempting to resolve this fundamental problem through
late-initialisation, and then locking the component into
a fixed memory location prior to actual usage. Driven by
the goal of a self-contained component, some advanced
trickery is required -- which again indicates better
to write a library component with adequate test coverage.
2023-12-03 04:59:18 +01:00