Completely refactor Modules/_remote_debugging_module.c with improved
code organization, replacing scattered reference counting and error
handling with centralized goto error paths. This cleanup improves
maintainability and reduces code duplication throughout the module while
preserving the same external API.
Implement memory page caching optimization in Python/remote_debug.h to
avoid repeated reads of the same memory regions during debugging
operations. The cache stores previously read memory pages and reuses
them for subsequent reads, significantly reducing system calls and
improving performance.
Add code object caching mechanism with a new code_object_generation
field in the interpreter state that tracks when code object caches need
invalidation. This allows efficient reuse of parsed code object metadata
and eliminates redundant processing of the same code objects across
debugging sessions.
Optimize memory operations by replacing multiple individual structure
copies with single bulk reads for the same data structures. This reduces
the number of memory operations and system calls required to gather
debugging information from the target process.
Update Makefile.pre.in to include Python/remote_debug.h in the headers
list, ensuring that changes to the remote debugging header force proper
recompilation of dependent modules and maintain build consistency across
the codebase.
Also, make the module compatible with the free threading build as an extra :)
Co-authored-by: Łukasz Langa <lukasz@langa.pl>
This reverts commit 3c73cf5 (gh-133497), which itself reverted
the original commit d270bb5 (gh-133221).
We reverted the original change due to failing android tests.
The checks in _PyCode_CheckNoInternalState() were too strict,
so we've relaxed them.
"Stateless" code is a function or code object which does not rely on external state or internal state.
It may rely on arguments and builtins, but not globals or a closure. I've left a comment in
pycore_code.h that provides more detail.
We also add _PyFunction_VerifyStateless(). The new functions will be used in several later changes
that facilitate "sharing" functions and code objects between interpreters.
This reverts commit 811edcf (gh-133232), which itself reverted the original commit 811edcf (gh-133128).
We reverted the original change due to failing s390 builds (a big-endian architecture).
It ended up that I had not accommodated op caches.
This helper is useful in a variety of ways, including in demonstrating how the different counts relate to one another.
It will be used in a later change to help identify if a function is "stateless", meaning it doesn't have any free vars or globals.
Note that a majority of this change is tests.
The function indicates whether or not the function has a return statement.
This is used by a later change related treating some functions like scripts.
The free-threading build interns and immortalizes most constants
generated by the bytecode compiler. However, users can construct their
own code objects with arbitrary constants. We should not intern or
immortalize these objects if they are not of a type that we know how to
handle.
This change fixes a reference leak failure in the recently added
`test_code.test_unusual_constants` test. It also addresses a potential
crash that could occur when attempting to destroy an immortalized
object during interpreter shutdown.
The bytecode compiler only generates a few different types of constants,
like str, int, tuple, slices, etc. Users can construct code objects with
various unusual constants, including ones that are not hashable or not
even constant.
The free threaded build previously crashed with a fatal error when
confronted with these constants. Instead, treat distinct objects of
otherwise unhandled types as not equal for the purposes of deduplication.
Remove inclusions prior to Python.h.
<stdbool.h> will cause <features.h> to be included before Python.h can
define some macros to enable some additional features, causing multiple
types not to be defined down the line.
In the free threading build, the per thread reference counting uses a
unique id for some objects to index into the local reference count
table. Use 0 instead of -1 to indicate that the id is not assigned. This
avoids bugs where zero-initialized heap type objects look like they have
a unique id assigned.
Objects may be temporarily "resurrected" in destructors when calling
finalizers or watcher callbacks. We previously undid the resurrection
by decrementing the reference count using `Py_SET_REFCNT`. This was not
thread-safe because other threads might be accessing the object
(modifying its reference count) if it was exposed by the finalizer,
watcher callback, or temporarily accessed by a racy dictionary or list
access.
This adds internal-only thread-safe functions for temporary object
resurrection during destructors.
This is a precursor to the actual fix for gh-114940, where we will change these macros to use the new lock. This change is almost entirely mechanical; the exceptions are the loops in codeobject.c and ceval.c, which now hold the "head" lock. Note that almost all of the uses of _Py_FOR_EACH_TSTATE_UNLOCKED() here will change to _Py_FOR_EACH_TSTATE_BEGIN() once we add the new per-interpreter lock.
* gh-126298: Don't deduplicated slice constants based on equality
* NULL check for PySlice_New
* Fix refcounting
* Fix refcounting some more
* Fix refcounting
* Make tests more complete
* Fix tests
Each thread specializes a thread-local copy of the bytecode, created on the first RESUME, in free-threaded builds. All copies of the bytecode for a code object are stored in the co_tlbc array on the code object. Threads reserve a globally unique index identifying its copy of the bytecode in all co_tlbc arrays at thread creation and release the index at thread destruction. The first entry in every co_tlbc array always points to the "main" copy of the bytecode that is stored at the end of the code object. This ensures that no bytecode is copied for programs that do not use threads.
Thread-local bytecode can be disabled at runtime by providing either -X tlbc=0 or PYTHON_TLBC=0. Disabling thread-local bytecode also disables specialization.
Concurrent modifications to the bytecode made by the specializing interpreter and instrumentation use atomics, with specialization taking care not to overwrite an instruction that was instrumented concurrently.
* Remove `@suppress_immortalization` decorator
* Make suppression flag per-thread instead of per-interpreter
* Suppress immortalization in `eval()` to avoid refleaks in three tests
(test_datetime.test_roundtrip, test_logging.test_config8_ok, and
test_random.test_after_fork).
* frozenset() is constant, but not a singleton. When run multiple times,
the test could fail due to constant interning.
Use per-thread refcounting for the reference from function objects to
their corresponding code object. This can be a source of contention when
frequently creating nested functions. Deferred refcounting alone isn't a
great fit here because these references are on the heap and may be
modified by other libraries.
* Make slices marshallable
* Emit slices as constants
* Update Python/marshal.c
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
* Refactor codegen_slice into two functions so it
always has the same net effect
* Fix for free-threaded builds
* Simplify marshal loading of slices
* Only return SUCCESS/ERROR from codegen_slice
---------
Co-authored-by: Mark Shannon <mark@hotpy.org>
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
* Add an InternalDocs file describing how interning should work and how to use it.
* Add internal functions to *explicitly* request what kind of interning is done:
- `_PyUnicode_InternMortal`
- `_PyUnicode_InternImmortal`
- `_PyUnicode_InternStatic`
* Switch uses of `PyUnicode_InternInPlace` to those.
* Disallow using `_Py_SetImmortal` on strings directly.
You should use `_PyUnicode_InternImmortal` instead:
- Strings should be interned before immortalization, otherwise you're possibly
interning a immortalizing copy.
- `_Py_SetImmortal` doesn't handle the `SSTATE_INTERNED_MORTAL` to
`SSTATE_INTERNED_IMMORTAL` update, and those flags can't be changed in
backports, as they are now part of public API and version-specific ABI.
* Add private `_only_immortal` argument for `sys.getunicodeinternedsize`, used in refleak test machinery.
* Make sure the statically allocated string singletons are unique. This means these sets are now disjoint:
- `_Py_ID`
- `_Py_STR` (including the empty string)
- one-character latin-1 singletons
Now, when you intern a singleton, that exact singleton will be interned.
* Add a `_Py_LATIN1_CHR` macro, use it instead of `_Py_ID`/`_Py_STR` for one-character latin-1 singletons everywhere (including Clinic).
* Intern `_Py_STR` singletons at startup.
* For free-threaded builds, intern `_Py_LATIN1_CHR` singletons at startup.
* Beef up the tests. Cover internal details (marked with `@cpython_only`).
* Add lots of assertions
Co-Authored-By: Eric Snow <ericsnowcurrently@gmail.com>
The free-threaded build currently immortalizes objects that use deferred
reference counting (see gh-117783). This typically happens once the
first non-main thread is created, but the behavior can be suppressed for
tests, in subinterpreters, or during a compile() call.
This fixes a race condition involving the tracking of whether the
behavior is suppressed.
The PEP 649 implementation will require a way to load NotImplementedError
from the bytecode. @markshannon suggested implementing this by converting
LOAD_ASSERTION_ERROR into a more general mechanism for loading constants.
This PR adds this new opcode. I will work on the rest of the implementation
of the PEP separately.
Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
We already intern and immortalize most string constants. In the
free-threaded build, other constants can be a source of reference count
contention because they are shared by all threads running the same code
objects.
This interns the strings for `co_filename`, `co_name`, and `co_qualname`
on codeobjects in the free-threaded build. This partially addresses a
reference counting bottleneck when creating closures concurrently. The
closures take the name and qualified name from the code object.
The code for Tier 2 is now only compiled when configured
with `--enable-experimental-jit[=yes|interpreter]`.
We drop support for `PYTHON_UOPS` and -`Xuops`,
but you can disable the interpreter or JIT
at runtime by setting `PYTHON_JIT=0`.
You can also build it without enabling it by default
using `--enable-experimental-jit=yes-off`;
enable with `PYTHON_JIT=1`.
On Windows, the `build.bat` script supports
`--experimental-jit`, `--experimental-jit-off`,
`--experimental-interpreter`.
In the C code, `_Py_JIT` is defined as before
when the JIT is enabled; the new variable
`_Py_TIER2` is defined when the JIT *or* the
interpreter is enabled. It is actually a bitmask:
1: JIT; 2: default-off; 4: interpreter.
We want code objects to use deferred reference counting in the
free-threaded build. This requires them to be tracked by the GC, so we
set `Py_TPFLAGS_HAVE_GC` in the free-threaded build, but not the default
build.
Pablo Galindo Salgado