The tests were flaky on slow machines because subprocesses could finish
before enough samples were collected. This adds synchronization similar
to test_external_inspection: test scripts now signal when they start
working, and the profiler waits for this signal before sampling.
Test scripts now run in infinite loops until killed rather than for
fixed iterations, ensuring the profiler always has active work to
sample regardless of machine speed.
This PR implements frame caching in the RemoteUnwinder class to significantly reduce memory reads when profiling remote processes with deep call stacks.
When cache_frames=True, the unwinder stores the frame chain from each sample and reuses unchanged portions in subsequent samples. Since most profiling samples capture similar call stacks (especially the parent frames), this optimization avoids repeatedly reading the same frame data from the target process.
The implementation adds a last_profiled_frame field to the thread state that tracks where the previous sample stopped. On the next sample, if the current frame chain reaches this marker, the cached frames from that point onward are reused instead of being re-read from remote memory.
The sampling profiler now enables frame caching by default.
Extend defect handling via policy to a couple of missed defects.
---------
Co-authored-by: Martin Panter <vadmium@users.noreply.github.com>
Co-authored-by: Ivo Bellin Salarin <ivo@nilleb.com>
The keyword typo suggestion mechanism in traceback would incorrectly
suggest replacements when the extracted source code was merely incomplete
rather than containing an actual typo. For example, when a missing comma
caused a syntax error, the system would suggest replacing 'print' with
'not' because the incomplete code snippet happened to pass validation.
The fix adds a validation step that first checks whether the original
extracted code raises a SyntaxError. If the code compiles successfully
or is simply incomplete (compile_command returns None), the function
returns early since there is no way to verify that a keyword replacement
would actually fix the problem.
RDM: This fixes a subtle folding error that showed up when a token exactly filled a line and was followed by whitespace and a token with no folding whitespace that was longer than a line. In this particular circumstance the whitespace after the first token got pushed on to the next line, and then stolen to go in front of the next unfoldable token...leaving a completely empty line in the line buffer. That line got turned in to a newline, which is RFC illegal, and the newish security check caught it. The fix is to just delete that empty line from the buffer.
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Enhanced the _find_lineno method in doctest to correctly identify and
report line numbers for doctests defined in __test__ dictionaries when
formatted as triple-quoted strings.
Finds a non-blank line in the test string and matches it in the source
file, verifying subsequent lines also match to handle duplicate lines.
Previously, doctest would report "line None" for __test__ dictionary
strings, making it difficult to debug failing tests.
Co-authored-by: Jurjen N.E. Bos <jneb@users.sourceforge.net>
Co-authored-by: R. David Murray <rdmurray@bitdance.com>
While CPython doesn't support `--enable-wasm-dynamic-linking`, external tools like componentize-py do and they have to patch around it. Since the flag is off by default, allowing the flag so external users can add/inject dynamic linking support seems acceptable.
It should make it easier when you need to rebuild just the e.g. host Python, but it requires ./configure to run.
Co-authored-by: Emma Smith <emma@emmatyping.dev>
Loading a small data which does not even involve arbitrary code execution
could consume arbitrary large amount of memory. There were three issues:
* PUT and LONG_BINPUT with large argument (the C implementation only).
Since the memo is implemented in C as a continuous dynamic array, a single
opcode can cause its resizing to arbitrary size. Now the sparsity of
memo indices is limited.
* BINBYTES, BINBYTES8 and BYTEARRAY8 with large argument. They allocated
the bytes or bytearray object of the specified size before reading into
it. Now they read very large data by chunks.
* BINSTRING, BINUNICODE, LONG4, BINUNICODE8 and FRAME with large
argument. They read the whole data by calling the read() method of
the underlying file object, which usually allocates the bytes object of
the specified size before reading into it. Now they read very large data
by chunks.
Also add comprehensive benchmark suite to measure performance and memory
impact of chunked reading optimization in PR #119204.
Features:
- Normal mode: benchmarks legitimate pickles (time/memory metrics)
- Antagonistic mode: tests malicious pickles (DoS protection)
- Baseline comparison: side-by-side comparison of two Python builds
- Support for truncated data and sparse memo attack vectors
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Co-authored-by: Gregory P. Smith <greg@krypto.org>
Add readline.get_pre_input_hook() to retrieve the current pre-input
hook. This allows applications to save and restore the hook without
overwriting user settings.
This fixes a regression introduced in gh-140558. The interpreter would
crash if we inserted a non `str` key into a split table that matches an
existing key.
The previous test_spawn_doesnt_hang test had a few problems:
* It would cause ENV CHANGED failures if other tests were running
concurrently due to stty changes
* Typing while the test was running could cause it to fail
