Avoid detaching thread state when stopping the world. When re-attaching
the thread state, the thread would attempt to resume the top-most
critical section, which might now be held by a thread paused for our
stop-the-world request.
Deferred reference counting is not fully implemented yet. As a temporary
measure, we immortalize objects that would use deferred reference
counting to avoid multi-threaded scaling bottlenecks.
This is only performed in the free-threaded build once the first
non-main thread is started. Additionally, some tests, including refleak
tests, suppress this behavior.
Basically, I've turned most of _PyImport_LoadDynamicModuleWithSpec() into two new functions (_PyImport_GetModInitFunc() and _PyImport_RunModInitFunc()) and moved the rest of it out into _imp_create_dynamic_impl(). There shouldn't be any changes in behavior.
This change makes some future changes simpler. This is particularly relevant to potentially calling each module init function in the main interpreter first. Thus the critical part of the PR is the addition of _PyImport_RunModInitFunc(), which is strictly focused on running the init func and validating the result. A later PR will take it a step farther by capturing error information rather than raising exceptions.
FWIW, this change also helps readers by clarifying a bit more about what happens when an extension/builtin module is imported.
These are cleanups I've pulled out of gh-118116. Mostly, this change moves code around to align with some future changes and to improve clarity a little. There is one very small change in behavior: we now add the module to the per-interpreter caches after updating the global state, rather than before.
This is a collection of very basic cleanups I've pulled out of gh-118116. It is mostly renaming variables and moving a couple bits of code in functionally equivalent ways.
Makes sys.settrace, sys.setprofile, and monitoring generally thread-safe.
Mostly uses a stop-the-world approach and synchronization around the code object's _co_instrumentation_version. There may be a little bit of extra synchronization around the monitoring data that's required to be TSAN clean.
We were under-counting calls in `_PyEvalFramePushAndInit`
because the `CALL_STAT_INC` macro was redefined to a no-op
for the Tier 2 interpreter. The fix is not to `#undef` it at all.
This results in ~37% more "Frames pushed" reported
under "Call stats".
Quiet erroneous TSAN reports of data races in `_PySeqLock`
TSAN reports a couple of data races between the compare/exchange in
`_PySeqLock_LockWrite` and the non-atomic loads in `_PySeqLock_{Abandon,Unlock}Write`.
This is another instance of TSAN incorrectly modeling failed compare/exchange
as a write instead of a load.
