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.
`_datetime` is a special module, because it's the only non-builtin C extension that contains static types. As such, it would initialize static types in the module's execution function, which can run concurrently. Since static type initialization is not thread-safe, this caused crashes. This fixes it by moving the initialization of `_datetime`'s static types to interpreter startup (where all other static types are initialized), which is already properly protected through other locks.
* Add _zstd module for https://peps.python.org/pep-0784/
This commit introduces the `_zstd` module, with bindings to libzstd from
the pyzstd project. It also includes the unix build system configuration.
Windows build system support will be integrated independently as it
depends on integration with cpython-source-deps.
* Add _zstd to modules
* Fix path for compression.zstd module
* Ignore _zstd module like _io
* Expand module state macros to improve code quality
Also removes module state references from the classes in the _zstd
module and instead uses PyType_GetModuleState()
* Remove backticks suggested in review
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
* Use critical sections to lock object state
This should avoid races and deadlocks.
* Remove compress/decompress and mark module as not reliant on the GIL
The `compress`/`decompress` functions will be moved to Python code for simplicity.
C implementations can always be re-added in the future.
Also, mark _zstd as not requiring the GIL.
* Lift critical section to avoid clang warning
* Respond to comments by picnixz
* Call out pyzstd explicitly in license description
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
* Use a much more robust implementation...
... for `get_zstd_state_from_type`
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
* Use PyList_GetItemRef for thread safety purposes
* Use a macro for the minimum supported version
* remove const from primivite types
* Use PyMem_New in another spot
* Simplify error handling in _get_frame_size
* Another simplification of error handling in get_frame_info
* Rename _module_state to mod_state
* Rewrite comment explaining the context of the code
* Add link to pyzstd
* Add TODO about refactoring dict training code
* Use PyModule_AddObjectRef over PyModule_AddObject
PyModule_AddObject is soft-deprecated, so we should use PyModule_AddObjectRef
* Check result of OutputBufferGrow
* Simplify return logic in `add_constant_to_type`
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
* Ignore return value of _zstd_clear()
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
* Remove redundant comments
* Remove __reduce__ from ZstdDict
We should instead document that to pickle a dictionary a user should use
the `.dict_content` attribute.
* Use PyUnicode_FromFormat instead of a buffer
* Don't use C constants/types in error messages
* Make error messages easier to understand for Python users
* Lower minimum required version 1.4.0
* Use casts and make slot function signatures correct
* Be consistent with CPython on const usage
* Make else clauses in line with PEP 7
* Fix over-indented blocks in argument clinic
* Add critical section around ZSTD_DCtx_setParameter
* Add a TODO about refactoring critical sections
* Use Py_UNREACHABLE
* Move bytes operations out of Py_BEGIN_ALLOW_THREADS
* Add TODO about ensuring a lock is held
* Remove asserts that may not be correct
* Add TODO to make ZstdDict and others GC objects
* Make objects GC tracked
* Remove unused include
* Fix some memory issues
* Fix refleaks on module and in ZstdDict
* Update configure to check for ZDICT_finalizeDictionary
* Properly check version in configure
* exit(1) if check fails
* Use AC_RUN_IFELSE
* Use a define() to re-use version check
* Actually properly set _zstd module status based on version
---------
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
* simplify HACL* build for MD5, SHA1, SHA2 and SHA3 modules
* remove statically linked libraries for HACL* implementation
* is it better now?
* is it better now?
* fixup
* Present HACL* as a static or shared library.
On WASI, extension modules based on HACL* require the HACL*
library to be linked statically. On other platforms, it can
be built dynamically.
* amend whitespace
* remove temporary .so file as it requires more symlinks
* avoid smelly symbols
* fixup checksums
* regen sbom
* fixup shell warnings and comments
* it *should* work
Make `warnings.catch_warnings()` use a context variable for holding
the warning filtering state if the `sys.flags.context_aware_warnings`
flag is set to true. This makes using the context manager thread-safe in
multi-threaded programs.
Add the `sys.flags.thread_inherit_context` flag. If true, starting a new
thread with `threading.Thread` will use a copy of the context
from the caller of `Thread.start()`.
Both these flags are set to true by default for the free-threaded build
and false for the default build.
Move the Python implementation of warnings.py into _py_warnings.py.
Make _contextvars a builtin module.
Co-authored-by: Kumar Aditya <kumaraditya@python.org>
A new extension module, `_hmac`, now exposes the HACL* HMAC (formally verified) implementation.
The HACL* implementation is used as a fallback implementation when the OpenSSL implementation of HMAC
is not available or disabled. For now, only named hash algorithms are recognized and SIMD support provided
by HACL* for the BLAKE2 hash functions is not yet used.
* Move PyFunction C API tests to a new file.
* Add Lib/test/test_capi/test_function.py.
* Move tests from test_capi.test_misc to test_capi.test_function.
Move PyType C API tests to a new file.
Move following tests from test_capi.test_misc to test_capi.test_type:
* BuiltinStaticTypesTests
* test_get_type_name()
* test_get_base_by_token()
* Add Lib/test/test_capi/test_frame.py file.
* Move C API tests from test_frame to test_capi.test_frame.
* Add Modules/_testcapi/frame.c file.
* Move C API tests from _testcapimodule.c to frame.c
Add tests for the following functions in test_capi.test_file:
* PyFile_FromFd()
* PyFile_GetLine()
* PyFile_NewStdPrinter()
* PyFile_WriteObject()
* PyFile_WriteString()
* PyObject_AsFileDescriptor()
Add Modules/_testlimitedcapi/file.c file.
Remove test_embed.StdPrinterTests which became redundant.
Add PyConfig_Get(), PyConfig_GetInt(), PyConfig_Set() and
PyConfig_Names() functions to get and set the current runtime Python
configuration.
Add visibility and "sys spec" to config and preconfig specifications.
_PyConfig_AsDict() now converts PyConfig.xoptions as a dictionary.
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
This replaces the existing hashlib Blake2 module with a single implementation that uses HACL\*'s Blake2b/Blake2s implementations. We added support for all the modes exposed by the Python API, including tree hashing, leaf nodes, and so on. We ported and merged all of these changes upstream in HACL\*, added test vectors based on Python's existing implementation, and exposed everything needed for hashlib.
This was joint work done with @R1kM.
See the PR for much discussion and benchmarking details. TL;DR: On many systems, 8-50% faster (!) than `libb2`, on some systems it appeared 10-20% slower than `libb2`.
Add Py_GetConstant() and Py_GetConstantBorrowed() functions.
In the limited C API version 3.13, getting Py_None, Py_False,
Py_True, Py_Ellipsis and Py_NotImplemented singletons is now
implemented as function calls at the stable ABI level to hide
implementation details. Getting these constants still return borrowed
references.
Add _testlimitedcapi/object.c and test_capi/test_object.py to test
Py_GetConstant() and Py_GetConstantBorrowed() functions.
* Split long.c tests of _testcapi into two parts: limited C API tests
in _testlimitedcapi and non-limited C API tests in _testcapi.
* Move testcapi_long.h from Modules/_testcapi/ to
Modules/_testlimitedcapi/.
* Add MODULE__TESTLIMITEDCAPI_DEPS to Makefile.pre.in.
Split unicode.c tests of _testcapi into two parts: limited C API
tests in _testlimitedcapi and non-limited C API tests in _testcapi.
Update test_codecs.
Split abstract.c and float.c tests of _testcapi into two parts:
limited C API tests in _testlimitedcapi and non-limited C API tests
in _testcapi.
Update test_bytes and test_class.
Move the following files from Modules/_testcapi/ to
Modules/_testlimitedcapi/:
* bytearray.c
* bytes.c
* pyos.c
* sys.c
Changes:
* Replace PyBytes_AS_STRING() with PyBytes_AsString().
* Replace PyBytes_GET_SIZE() with PyBytes_Size().
* Update related test_capi tests.
* Copy Modules/_testcapi/util.h to Modules/_testlimitedcapi/util.h.
Add a new C extension "_testlimitedcapi" which is only built with the
limited C API.
Move heaptype_relative.c and vectorcall_limited.c from
Modules/_testcapi/ to Modules/_testlimitedcapi/.
* configure: add _testlimitedcapi test extension.
* Update generate_stdlib_module_names.py.
* Update make check-c-globals.
Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>
Petr Viktorin