* Add signal_state_t structure and signal_global_state variable.
* Add a module state to the _signal module.
* Move and rename variables:
* DefaultHandler becomes state->default_handler
* IgnoreHandler becomes state->ignore_handler
* sigint_event becomes state->sigint_event
* ItimerError becomes modstate->itimer_error
* Rename SetHandler() to set_handler() to be consistent with
get_handler().
Importing the _signal module in a subinterpreter has no longer side
effects.
signal_module_exec() no longer modifies Handlers and no longer attempts
to set SIGINT signal handler in subinterpreters.
We can receive signals (at the C level, in `trip_signal()` in signalmodule.c) while `signal.signal` is being called to modify the corresponding handler. Later when `PyErr_CheckSignals()` is called to handle the given signal, the handler may be a non-callable object and would raise a cryptic asynchronous exception.
* Add signal_add_constants() function and add ADD_INT_MACRO macro.
* The Python SIGINT handler is now installed at the end of
signal_exec().
* Use Py_NewRef().
bpo-41686, bpo-41713: On Windows, the SIGINT event,
_PyOS_SigintEvent(), is now created even if Python is configured to
not install signal handlers (PyConfig.install_signal_handlers=0 or
Py_InitializeEx(0)).
Changes:
* Move global variables initialization from signal_exec() to
_PySignal_Init() to clarify that they are global variables cleared
by _PySignal_Fini().
* _PySignal_Fini() now closes sigint_event.
* IntHandler is no longer a global variable.
Remove the undocumented PyOS_InitInterrupts() C function.
* Rename PyOS_InitInterrupts() to _PySignal_Init(). It now installs
other signal handlers, not only SIGINT.
* Rename PyOS_FiniInterrupts() to _PySignal_Fini()
These functions are considered not safe because they suppress all internal errors
and can return wrong result. PyDict_GetItemString and _PyDict_GetItemId can
also silence current exception in rare cases.
Remove no longer used _PyDict_GetItemId.
Add _PyDict_ContainsId and rename _PyDict_Contains into
_PyDict_Contains_KnownHash.
siginterrupt is deprecated:
./Modules/signalmodule.c:667:5: warning: ‘siginterrupt’ is deprecated: Use sigaction with SA_RESTART instead [-Wdeprecated-declarations]
667 | if (siginterrupt(signalnum, flag)<0) {
my_fgets() now calls _PyOS_InterruptOccurred(tstate) to check for
pending signals, rather calling PyOS_InterruptOccurred().
my_fgets() is called with the GIL released, whereas
PyOS_InterruptOccurred() must be called with the GIL held.
test_repl: use text=True and avoid SuppressCrashReport in
test_multiline_string_parsing().
Fix my_fgets() on Windows: fgets(fp) does crash if fileno(fp) is closed.
PyOS_AfterFork_Child() helper functions now return a PyStatus:
PyOS_AfterFork_Child() is now responsible to handle errors.
* Move _PySignal_AfterFork() to the internal C API
* Add #ifdef HAVE_FORK on _PyGILState_Reinit(), _PySignal_AfterFork()
and _PyInterpreterState_DeleteExceptMain().
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.
Fix the signal handler: it now always uses the main interpreter,
rather than trying to get the current Python thread state.
The following function now accepts an interpreter, instead of a
Python thread state:
* _PyEval_SignalReceived()
* _Py_ThreadCanHandleSignals()
* _PyEval_AddPendingCall()
* COMPUTE_EVAL_BREAKER()
* SET_GIL_DROP_REQUEST(), RESET_GIL_DROP_REQUEST()
* SIGNAL_PENDING_CALLS(), UNSIGNAL_PENDING_CALLS()
* SIGNAL_PENDING_SIGNALS(), UNSIGNAL_PENDING_SIGNALS()
* SIGNAL_ASYNC_EXC(), UNSIGNAL_ASYNC_EXC()
Py_AddPendingCall() now uses the main interpreter if it fails to the
current Python thread state.
Convert _PyThreadState_GET() and PyInterpreterState_GET_UNSAFE()
macros to static inline functions.
COMPUTE_EVAL_BREAKER() now also checks if the Python thread state
belongs to the main interpreter. Don't break the evaluation loop if
there are pending signals but the Python thread state it belongs to a
subinterpeter.
* Add _Py_IsMainThread() function.
* Add _Py_ThreadCanHandleSignals() function.
If Py_AddPendingCall() is called in a subinterpreter, the function is
now scheduled to be called from the subinterpreter, rather than being
called from the main interpreter.
Each subinterpreter now has its own list of scheduled calls.
* Move pending and eval_breaker fields from _PyRuntimeState.ceval
to PyInterpreterState.ceval.
* new_interpreter() now calls _PyEval_InitThreads() to create
pending calls lock.
* Fix Py_AddPendingCall() for subinterpreters. It now calls
_PyThreadState_GET() which works in a subinterpreter if the
caller holds the GIL, and only falls back on
PyGILState_GetThisThreadState() if _PyThreadState_GET()
returns NULL.
bpo-37127, bpo-39984:
* trip_signal() and Py_AddPendingCall() now get the current Python
thread state using PyGILState_GetThisThreadState() rather than
_PyRuntimeState_GetThreadState() to be able to get it even if the
GIL is released.
* _PyEval_SignalReceived() now expects tstate rather than ceval.
* Remove ceval parameter of _PyEval_AddPendingCall(): ceval is now
get from tstate parameter.
This exposes a Linux-specific syscall for sending a signal to a process
identified by a file descriptor rather than a pid.
For simplicity, we don't support the siginfo_t parameter to the syscall. This
parameter allows implementing a pidfd version of rt_sigqueueinfo(2), which
Python also doesn't support.
Remove main_thread and main_interp variables from signalmodule.c:
reuse _PyRuntime which already track the main thread and the main
interpreter.
* Remove #include <sys/types.h> which became useless: getpid() call
has been removed.
* Add runtime argument to is_main()
* is_main() now gets the interpreter from runtime.
Add "struct _ceval_runtime_state *ceval = &_PyRuntime.ceval;" local
variables to function to better highlight the dependency on the
global variable _PyRuntime and to point directly to _PyRuntime.ceval
field rather than on the larger _PyRuntime.
Changes:
* Add _PyRuntimeState_GetThreadState(runtime) macro.
* Add _PyEval_AddPendingCall(ceval, ...) and
_PyThreadState_Swap(gilstate, ...) functions.
* _PyThreadState_GET() macro now calls
_PyRuntimeState_GetThreadState() using &_PyRuntime.
* Add 'ceval' parameter to COMPUTE_EVAL_BREAKER(),
SIGNAL_PENDING_SIGNALS(), _PyEval_SignalAsyncExc(),
_PyEval_SignalReceived() and _PyEval_FiniThreads() macros and
functions.
* Add 'tstate' parameter to call_function(), do_call_core() and
do_raise().
* Add 'runtime' parameter to _Py_CURRENTLY_FINALIZING(),
_Py_FinishPendingCalls() and _PyThreadState_DeleteExcept()
macros and functions.
* Declare 'runtime', 'tstate', 'ceval' and 'eval_breaker' variables
as constant.
This is effectively an un-revert of #11617 and #12024 (reverted in #12159). Portions of those were merged in other PRs (with lower risk) and this represents the remainder. Note that I found 3 different bugs in the original PRs and have fixed them here.
* Revert "bpo-36097: Use only public C-API in the_xxsubinterpreters module (adding as necessary). (#12003)"
This reverts commit bcfa450f21.
* Revert "bpo-33608: Simplify ceval's DISPATCH by hoisting eval_breaker ahead of time. (gh-12062)"
This reverts commit bda918bf65.
* Revert "bpo-33608: Use _Py_AddPendingCall() in _PyCrossInterpreterData_Release(). (gh-12024)"
This reverts commit b05b711a2c.
* Revert "bpo-33608: Factor out a private, per-interpreter _Py_AddPendingCall(). (GH-11617)"
This reverts commit ef4ac967e2.
Ensure that the main interpreter is active (in the main thread) for signal-handling operations. This is increasingly relevant as people use subinterpreters more.
https://bugs.python.org/issue35724
This change separates the signal handling trigger in the eval loop from the "pending calls" machinery. There is no semantic change and the difference in performance is insignificant.
The change makes both components less confusing. It also eliminates the risk of changes to the pending calls affecting signal handling. This is particularly relevant for some upcoming pending calls changes I have in the works.
As in title, expose C `raise` function as `raise_function` in `signal` module. Also drop existing `raise_signal` in `_testcapi` module and replace all usages with new function.
https://bugs.python.org/issue35568
Fix invalid function cast warnings with gcc 8
for method conventions different from METH_NOARGS, METH_O and
METH_VARARGS excluding Argument Clinic generated code.
Introduce a configure check for strsignal(3) which defines HAVE_STRSIGNAL for
signalmodule.c. Add some common signals on HP-UX. This change applies for
Windows and HP-UX.
Victor Stinner
Antoine Pitrou
pxinwr
Serhiy Storchaka
Mohamed Koubaa
Pablo Galindo
Saiyang Gou
Benjamin Peterson
animalize
Jeroen Demeyer
Victor Stinner
Eric Snow
Matěj Cepl
Joannah Nanjekye
Vladimir Matveev
Michael Osipov