Allocation in threaded or multi-core code

[peterhinch]

Are the following statements true?

1. Code running on another core must not allocate.
2. On a single core, code running in a spawned thread must not allocate.

[dlech]

I don't think so. If GIL is enabled, then allocation is protected by the GIL. If GIL is disabled, then GC_ENTER()/GC_EXIT() are defined as a global gc_mutex lock/unlock to ensure synchronized access to the GC.

[jimmo]

Yep that's right. In both cases, GIL (esp32) or no-GIL (unix/rp2), any Python code can allocate regardless of which thread.