Use OnceLock instead of OnceCell #13410
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
OnceLock is a thread-safe version of OnceCell that enables us to use PackedInstruction from a threaded environment. There is some overhead associated with this, primarily in memory as the OnceLock is a larger type than a OnceCell. But the tradeoff is worth it to start leverage multithreading for circuits. Fixes Qiskit#13219
mtreinish
added
performance
Changelog: None
|
One or more of the following people are relevant to this code:
|
mtreinish
added a commit
to mtreinish/qiskit-core
that referenced
this pull request
Nov 8, 2024
With Qiskit#13410 removing the non-threadsafe structure from our circuit representation we're now able to read and iterate over a DAGCircuit from multiple threads. This commit is the first small piece doing this, it moves the analysis portion of the BarrierBeforeFinalMeasurements pass to execure in parallel. The pass checks every node to ensure all it's decendents are either a measure or a barrier before reaching the end of the circuit. This commit iterates over all the nodes and does the check in parallel.
Pull Request Test Coverage Report for Build 11766429415Details
💛 - Coveralls |
3 tasks
kevinhartman
reviewed
Nov 8, 2024
6 tasks
|
After 8bc4844 merged fixing the asv tests I did a quick asv run which yielded basically no change: This is mostly expected because we only use the py gate cache if when we're interacting with Python which will always end up being the bottleneck. The exception I guess is |
kevinhartman
approved these changes
Nov 11, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary
OnceLock is a thread-safe version of OnceCell that enables us to use PackedInstruction from a threaded environment. There is some overhead associated with this, primarily in memory as the OnceLock is a larger type than a OnceCell. But the tradeoff is worth it to start leverage multithreading for circuits.
Details and comments
Fixes #13219