Cancellation

[vu3rdd]

Reuse existing context than creating new contexts.

Code Review Checklist (to be filled out by reviewer)

• Description accurately reflects what changes are being made.
• Description explains why the changes are being made (or references an issue containing one).
• The PR appropriately sized.
• New code has enough tests.
• New code has enough documentation to answer "how do I use it?" and "what does it do?".
• Existing documentation is up-to-date, if impacted.