Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Rewrite singleton handling including SingletonInstruction #11014

Merged
merged 5 commits into from
Oct 13, 2023
Merged

Rewrite singleton handling including SingletonInstruction #11014

merged 5 commits into from
Oct 13, 2023

Commits on Oct 13, 2023

  1. Rewrite singleton handling including SingletonInstruction 

    This is a large rewrite of the singleton gate handling, building off the
work done across the library to make the initial implementation work.

There are two main purposes to this commit:

* Make `SingletonInstruction` available in addition to `SingletonGate`,
  and have these be easy to maintain in conjunction, not need to
  duplicate overrides between them, and not require inheritors to do any
  nasty multiple inheritance or the like.

* Fix regressions in the construction time of `SingletonGate` instances.

In the end, this turned into a fairly complete rewrite that completely
switches out the method of defining the classes; it transpires that the
previous way of having the "immutable overrides" on _all_ instances of
the classes was the main source of slowdown, with `__setattr__` being a
large problem.  The previous method was far easier from an
implementation perspective, but the runtime costs ended up being too
high.

This new form takes a vastly different strategy, explained in detail in
`qiskit/circuit/singleton.py`.  The gist is that we instead make the
singleton instance a _subclass_ of the class object we're creating, and
only it contains the overrides to make itself immutable.  We get around
the instantiation problem (`__init__` isn't special and doesn't
skip the forbidden `__setattr__`) by constructing an instance of the
_base_ class, and then dynamically switching in the overrides
afterwards.  Since the overrides and the dynamic singleton type of the
instance are designed to be co-operative (including in `__slots__`
layout), this can be done safely.
    @jakelishman
    jakelishman committed Oct 13, 2023
    Configuration menu
    Copy the full SHA
    4cf52f2 View commit details
    Browse the repository at this point in the history

  2. Make singleton documentation public

    @jakelishman
    jakelishman committed Oct 13, 2023
    Configuration menu
    Copy the full SHA
    145decf View commit details
    Browse the repository at this point in the history

  3. Add tests of new singleton behaviour

    @jakelishman
    jakelishman committed Oct 13, 2023
    Configuration menu
    Copy the full SHA
    1274fe7 View commit details
    Browse the repository at this point in the history

  4. Merge remote-tracking branch 'ibm/main' into singleton-instruction

    @jakelishman
    jakelishman committed Oct 13, 2023
    Configuration menu
    Copy the full SHA
    e1cde2f View commit details
    Browse the repository at this point in the history

  5. Fix typos 

    Co-authored-by: Matthew Treinish <mtreinish@kortar.org>
    @jakelishman @mtreinish
    jakelishman and mtreinish committed Oct 13, 2023
    Configuration menu
    Copy the full SHA
    f3c6a43 View commit details
    Browse the repository at this point in the history