Changelog

Release "B" based on Python 3.9.9 (Jan 2022)

• Rebased changes on top of 3.9.9 and refactored changes into logical commits
• Fix potential deadlocks in GC due to stop-the-world
• Made "set" object thread-safe
• Fix multi-threaded scaling issue when calling methods on objects
• Fix cProfile and other features that depend on bytecode tracing
• Fix GDB Python support with new interpreter
• New "critical section" implementation (pycore_critical_section.h) that simplifies internal object locks

Release "A" based on Python 3.9.0a3 (Sep 2021)

• Initial release of "nogil" Python
• See design document for details.