Instead of surprise crashes and memory corruption, we now hang threads that attempt to re-enter the Python interpreter after Python runtime finalization has started. These are typically daemon threads (our long standing mis-feature) but could also be threads spawned by extension modules that then try to call into Python. This marks the `PyThread_exit_thread` public C API as deprecated as there is no plausible safe way to accomplish that on any supported platform in the face of things like C++ code with finalizers anywhere on a thread's stack. Doing this was the least bad option.
Co-authored-by: Gregory P. Smith <greg@krypto.org>
Use _PyDeadline_Init() and _PyDeadline_Get() in
EnterNonRecursiveMutex() of thread_nt.h.
_PyDeadline_Get() uses the monotonic clock which is now the same as
the perf counter clock on all platforms. So this change does not
cause any behavior change. It just reuses existing helper functions.
PyTime_t no longer uses an arbitrary unit, it's always a number of
nanoseconds (64-bit signed integer).
* Rename _PyTime_FromNanosecondsObject() to _PyTime_FromLong().
* Rename _PyTime_AsNanosecondsObject() to _PyTime_AsLong().
* Remove pytime_from_nanoseconds().
* Remove pytime_as_nanoseconds().
* Remove _PyTime_FromNanoseconds().
<pycore_time.h> include is no longer needed to get the PyTime_t type
in internal header files. This type is now provided by <Python.h>
include. Add <pycore_time.h> includes to C files instead.
This marks dead ThreadHandles as non-joinable earlier in
`PyOS_AfterFork_Child()` before we execute any Python code. The handles
are stored in a global linked list in `_PyRuntimeState` because `fork()`
affects the entire process.
Joining a thread now ensures the underlying OS thread has exited. This is required for safer fork() in multi-threaded processes.
---------
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
This parallels _PyRuntimeState.interpreters. Doing this helps make it more clear what part of PyInterpreterState relates to its threads.
https://bugs.python.org/issue46008
Add a private C API for deadlines: add _PyDeadline_Init() and
_PyDeadline_Get() functions.
* Add _PyTime_Add() and _PyTime_Mul() functions which compute t1+t2
and t1*t2 and clamp the result on overflow.
* _PyTime_MulDiv() now uses _PyTime_Add() and _PyTime_Mul().
WaitForSingleObject() accepts timeout in milliseconds in the range
[0; 0xFFFFFFFE] (DWORD type). INFINITE value (0xFFFFFFFF) means no
timeout. 0xFFFFFFFE milliseconds is around 49.7 days.
PY_TIMEOUT_MAX is (0xFFFFFFFE * 1000) milliseconds on Windows, around
49.7 days.
Partially revert commit 37b8294d62.
PyThread_acquire_lock_timed() now clamps the timeout into the
[_PyTime_MIN; _PyTime_MAX] range (_PyTime_t type) if it is too large,
rather than calling Py_FatalError() which aborts the process.
PyThread_acquire_lock_timed() no longer uses
MICROSECONDS_TO_TIMESPEC() to compute sem_timedwait() argument, but
_PyTime_GetSystemClock() and _PyTime_AsTimespec_truncate().
Fix _thread.TIMEOUT_MAX value on Windows: the maximum timeout is
0x7FFFFFFF milliseconds (around 24.9 days), not 0xFFFFFFFF
milliseconds (around 49.7 days).
Set PY_TIMEOUT_MAX to 0x7FFFFFFF milliseconds, rather than 0xFFFFFFFF
milliseconds.
Fix PY_TIMEOUT_MAX overflow test: replace (us >= PY_TIMEOUT_MAX) with
(us > PY_TIMEOUT_MAX).
Mark the following thread_nt.h functions as static:
* AllocNonRecursiveMutex()
* FreeNonRecursiveMutex()
* EnterNonRecursiveMutex()
* LeaveNonRecursiveMutex()
Rename _PyInterpreterState_GET_UNSAFE() to _PyInterpreterState_GET()
for consistency with _PyThreadState_GET() and to have a shorter name
(help to fit into 80 columns).
Add also "assert(tstate != NULL);" to the function.
The 32-bit (49-day) TickCount relied on in EnterNonRecursiveMutex can overflow
in the gap between the 'target' time and the 'now' time WaitForSingleObjectEx
returns, causing the loop to think it needs to wait another 49 days. This is
most likely to happen when the machine is hibernated during
WaitForSingleObjectEx.
This makes acquiring a lock/event/etc from the _thread or threading module
appear to never timeout.
Replace with GetTickCount64 - this is OK now Python no longer supports XP which
lacks it, and is in use for time.monotonic().
Co-authored-by: And Clover <and.clover@bromium.com>
If Py_BUILD_CORE is defined, the PyThreadState_GET() macro access
_PyRuntime which comes from the internal pycore_state.h header.
Public headers must not require internal headers.
Move PyThreadState_GET() and _PyInterpreterState_GET_UNSAFE() from
Include/pystate.h to Include/internal/pycore_state.h, and rename
PyThreadState_GET() to _PyThreadState_GET() there.
The PyThreadState_GET() macro of pystate.h is now redefined when
pycore_state.h is included, to use the fast _PyThreadState_GET().
Changes:
* Add _PyThreadState_GET() macro
* Replace "PyThreadState_GET()->interp" with
_PyInterpreterState_GET_UNSAFE()
* Replace PyThreadState_GET() with _PyThreadState_GET() in internal C
files (compiled with Py_BUILD_CORE defined), but keep
PyThreadState_GET() in the public header files.
* _testcapimodule.c: replace PyThreadState_GET() with
PyThreadState_Get(); the module is not compiled with Py_BUILD_CORE
defined.
* pycore_state.h now requires Py_BUILD_CORE to be defined.
kB (*kilo* byte) unit means 1000 bytes, whereas KiB ("kibibyte")
means 1024 bytes. KB was misused: replace kB or KB with KiB when
appropriate.
Same change for MB and GB which become MiB and GiB.
Change the output of Tools/iobench/iobench.py.
Round also the size of the documentation from 5.5 MB to 5 MiB.
Fix the pthread+semaphore implementation of
PyThread_acquire_lock_timed() when called with timeout > 0 and
intr_flag=0: recompute the timeout if sem_timedwait() is interrupted
by a signal (EINTR).
See also the PEP 475.
The pthread implementation of PyThread_acquire_lock() now fails with
a fatal error if the timeout is larger than PY_TIMEOUT_MAX, as done
in the Windows implementation.
The check prevents any risk of overflow in PyThread_acquire_lock().
Add also PY_DWORD_MAX constant.
See PEP 539 for details.
Highlights of changes:
- Add Thread Specific Storage (TSS) API
- Document the Thread Local Storage (TLS) API as deprecated
- Update code that used TLS API to use TSS API
* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals
Other globals are excluded (see globals.txt and check-c-globals.py).
* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals
Other globals are excluded (see globals.txt and check-c-globals.py).
* bpo-30832: Remove own implementation for thread-local storage
CPython has provided the own implementation for thread-local storage
(TLS) on Python/thread.c, it's used in the case which a platform has
not supplied native TLS. However, currently all supported platforms
(NT and pthreads) have provided native TLS and defined the
Py_HAVE_NATIVE_TLS macro with unconditional in any case.
* bpo-30832: replace NT with Windows
* bpo-30832: change to directive chain
* bpo-30832: remove comemnt which making no sense
* bpo-6532: Make the thread id an unsigned integer.
From C API side the type of results of PyThread_start_new_thread() and
PyThread_get_thread_ident(), the id parameter of
PyThreadState_SetAsyncExc(), and the thread_id field of PyThreadState
changed from "long" to "unsigned long".
* Restore a check in thread_get_ident().
in order to have the same resolution as pthreads condition variables.
At the same time, it must be large enough to accept 31 bits of
milliseconds, which is the maximum timeout value in the windows API.
A PY_LONG_LONG of microseconds fullfills both requirements.
This closes issue #20737
In Python 3.3, PyThread_set_key_value() did nothing if the key already exists
(if the current value is a non-NULL pointer).
When _PyGILState_NoteThreadState() is called twice on the same thread with a
different Python thread state, it still keeps the old Python thread state to
keep the old behaviour. Replacing the Python thread state with the new state
introduces new bugs: see issues #10915 and #15751.
the function did nothing if the key already exists (if the current value is a
non-NULL pointer).
_testcapi.run_in_subinterp() now correctly sets the new Python thread state of
the current thread when a subinterpreter is created.
Jeremy Maitin-Shepard
Victor Stinner
Steve Dower
Sam Gross
Andrew Rogers
Antoine Pitrou
Eric Snow
Gregory P. Smith
Ryan Hileman
bobince
Jake Tesler
Victor Stinner
native-api
hui shang
Victor Stinner
Masayuki Yamamoto
Serhiy Storchaka
Benjamin Peterson
Larry Hastings
Kristján Valur Jónsson
Martin v. Löwis
Kristján Valur Jónsson
Antoine Pitrou