There were a few thread-safety issues when profiling or tracing all
threads via PyEval_SetProfileAllThreads or PyEval_SetTraceAllThreads:
* The loop over thread states could crash if a thread exits concurrently
(in both the free threading and default build)
* The modification of `c_profilefunc` and `c_tracefunc` wasn't
thread-safe on the free threading build.
Move PYOS_LOG2_STACK_MARGIN, PYOS_STACK_MARGIN,
PYOS_STACK_MARGIN_BYTES and PYOS_STACK_MARGIN_SHIFT macros to
pycore_pythonrun.h internal header. Add underscore (_) prefix to the
names to make them private. Rename _PYOS to _PyOS.
For several builtin functions, we now fall back to __main__.__dict__ for the globals
when there is no current frame and _PyInterpreterState_IsRunningMain() returns
true. This allows those functions to be run with Interpreter.call().
The affected builtins:
* exec()
* eval()
* globals()
* locals()
* vars()
* dir()
We take a similar approach with "stateless" functions, which don't use any
global variables.
In the free-threaded build, avoid data races caused by updating type
slots or type flags after the type was initially created. For those
(typically rare) cases, use the stop-the-world mechanism. Remove the
use of atomics when reading or writing type flags.
* FOR_ITER now pushes either the iterator and NULL or leaves the iterable and pushes tagged zero
* NEXT_ITER uses the tagged int as the index into the sequence or, if TOS is NULL, iterates as before.
Removed special-casing for WASI when setting C stack depth limits. Since WASI has its own C stack checking this isn't a security risk.
Also disabled some tests that stopped passing. They all happened to have already been disabled under Emscripten.
* Track the current executor, not the previous one, on the thread-state.
* Batch executors for deallocation to avoid having to constantly incref executors; this is an ad-hoc form of deferred reference counting.
In the free-threaded build, avoid data races caused by updating type slots
or type flags after the type was initially created. For those (typically
rare) cases, use the stop-the-world mechanism. Remove the use of atomics
when reading or writing type flags. The use of atomics is not sufficient to
avoid races (since flags are sometimes read without a lock and without
atomics) and are no longer required.
Improve the error message with a suggestion when an object supporting the synchronous
(resp. asynchronous) context manager protocol is entered using `async with` (resp. `with`)
instead of `with` (resp. `async with`).
Only disable SLP autovectorization of `_PyEval_EvalFrameDefault` on newer
GCCs, as the optimization bug seems to exist only on GCC 12 and later, and
before GCC 9 disabling the optimization has a dramatic performance impact.
Mark a few functions used by the interpreter loop as noinline
These are all the slow path and should not be inlined into the interpreter
loop. Unfortunately, they end up being inlined with LTO and the current PGO
task.
