gh-151613: Fix remote debugging frame cache ABA (#151614)
The remote debugging frame cache previously used only the last_profiled_frame address as its cache anchor. If a frame returned and a later frame reused the same _PyInterpreterFrame address, the profiler could accept a stale cache entry and splice parent frames from a different call chain into the current stack.
This adds a last_profiled_frame_seq counter next to last_profiled_frame, increments it when the anchor advances, stores it in frame cache entries, and validates cache hits against both the frame address and the sequence. Cache miss walks now copy stack chunks before storing new cache entries so stored continuations come from a stable snapshot. The new regression test exercises alternating call chains and checks that cached stacks never contain frames from both branches.
(cherry picked from commit 8cda6ae2f1)
This mimics an optimization already present for the single-mutex critical section.
(cherry picked from commit c2ca7724af)
Co-authored-by: Daniele Parmeggiani <8658291+dpdani@users.noreply.github.com>
gh-150907: Fix dynamic_annotations.h when built with C++ and Valgrind (GH-150914)
Add extern "C++" scope for the C++ template.
Fix test_cppext when Python is built with --with-valgrind.
(cherry picked from commit c32501261a)
Co-authored-by: Victor Stinner <vstinner@python.org>
In free-threaded builds, concurrent calls to PyDict_AddWatcher, PyDict_ClearWatcher, PyDict_Watch, and PyDict_Unwatch can race on the shared callback array and the per-dict watcher tags. This change adds a mutex to serialize watcher registration and removal, atomic operations for tag updates, and atomic acquire/release synchronization for callback dispatch in _PyDict_SendEvent.
(cherry picked from commit 8a4895985f)
Co-authored-by: Alper <alperyoney@fb.com>
* SEND specialization. Adds 2 new specialized instructions:
* SEND_VIRTUAL: for sends to virtual iterators e.g lists and tuples
* SEND_ASYNC_GEN: for sends to async generators
Tweak FOR_ITER_VIRTUAL so that SEND_VIRTUAL and FOR_ITER_VIRTUAL use equivalent guards
When someone adds a new type but doesn't increment
`_Py_MAX_MANAGED_STATIC_BUILTIN_TYPES` or
`_Py_MAX_MANAGED_STATIC_EXT_TYPES`, JIT tests fail,
because JIT builds define an extra type.
But the JIT tests don't necessarily run for the commit
that causes the failure.
As a workaround, use the same size for the array for all
builds, potentially with an empty spot.
Add a keyword-only `max_threads` argument to `dump_traceback()` and
`dump_traceback_later()`, defaulting to 100 to preserve existing
behavior. Allows server processes with many worker threads to dump
beyond the historical 100-thread cap (previously a hardcoded
`MAX_NTHREADS = 100` in `Python/traceback.c`).
The cap matters in practice: tstates are prepended to the
PyInterpreterState linked list, so the dump walks newest-first. With
more than 100 threads alive, the main thread (oldest, at the tail) is
silently elided from watchdog dumps -- exactly the thread that's
usually wanted.
The hardcoded value is moved to a new internal macro
`_Py_TRACEBACK_MAX_NTHREADS` in `pycore_traceback.h` so the in-tree
fatal-signal callers all reference one source of truth.
Pablo Galindo Salgado