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bpo-40082: trip_signal() uses the main interpreter #19441

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Merged
vstinner merged 1 commit into from
Apr 8, 2020
Merged

bpo-40082: trip_signal() uses the main interpreter #19441

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4 changes: 2 additions & 2 deletions Include/internal/pycore_ceval.h
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Original file line number Diff line number Diff line change
Expand Up @@ -19,9 +19,9 @@ extern void _Py_FinishPendingCalls(PyThreadState *tstate);
extern void _PyEval_InitRuntimeState(struct _ceval_runtime_state *);
extern int _PyEval_InitState(struct _ceval_state *ceval);
extern void _PyEval_FiniState(struct _ceval_state *ceval);
PyAPI_FUNC(void) _PyEval_SignalReceived(PyThreadState *tstate);
PyAPI_FUNC(void) _PyEval_SignalReceived(PyInterpreterState *interp);
PyAPI_FUNC(int) _PyEval_AddPendingCall(
PyThreadState *tstate,
PyInterpreterState *interp,
int (*func)(void *),
void *arg);
PyAPI_FUNC(void) _PyEval_SignalAsyncExc(PyThreadState *tstate);
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13 changes: 9 additions & 4 deletions Include/internal/pycore_pystate.h
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Expand Up @@ -310,9 +310,9 @@ _Py_IsMainInterpreter(PyThreadState* tstate)

/* Only handle signals on the main thread of the main interpreter. */
static inline int
_Py_ThreadCanHandleSignals(PyThreadState *tstate)
_Py_ThreadCanHandleSignals(PyInterpreterState *interp)
{
return (_Py_IsMainThread() && _Py_IsMainInterpreter(tstate));
return (_Py_IsMainThread() && interp == _PyRuntime.interpreters.main);
}


Expand Down Expand Up @@ -340,7 +340,9 @@ static inline PyThreadState* _PyRuntimeState_GetThreadState(_PyRuntimeState *run
The caller must hold the GIL.

See also PyThreadState_Get() and PyThreadState_GET(). */
#define _PyThreadState_GET() _PyRuntimeState_GetThreadState(&_PyRuntime)
static inline PyThreadState *_PyThreadState_GET(void) {
return _PyRuntimeState_GetThreadState(&_PyRuntime);
}

/* Redefine PyThreadState_GET() as an alias to _PyThreadState_GET() */
#undef PyThreadState_GET
Expand All @@ -354,7 +356,10 @@ static inline PyThreadState* _PyRuntimeState_GetThreadState(_PyRuntimeState *run

See also _PyInterpreterState_Get()
and _PyGILState_GetInterpreterStateUnsafe(). */
#define _PyInterpreterState_GET_UNSAFE() (_PyThreadState_GET()->interp)
static inline PyInterpreterState* _PyInterpreterState_GET_UNSAFE(void) {
PyThreadState *tstate = _PyThreadState_GET();
return tstate->interp;
}


/* Other */
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2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2020-04-08-22-33-24.bpo-40082.WI3-lu.rst
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@@ -0,0 +1,2 @@
Fix the signal handler: it now always uses the main interpreter, rather than
trying to get the current Python thread state.
27 changes: 12 additions & 15 deletions Modules/signalmodule.c
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Expand Up @@ -252,14 +252,11 @@ trip_signal(int sig_num)
cleared in PyErr_CheckSignals() before .tripped. */
_Py_atomic_store(&is_tripped, 1);

/* Get the Python thread state using PyGILState API, since
_PyThreadState_GET() returns NULL if the GIL is released.
For example, signal.raise_signal() releases the GIL. */
PyThreadState *tstate = PyGILState_GetThisThreadState();
assert(tstate != NULL);
/* Signals are always handled by the main interpreter */
PyInterpreterState *interp = _PyRuntime.interpreters.main;

/* Notify ceval.c */
_PyEval_SignalReceived(tstate);
_PyEval_SignalReceived(interp);

/* And then write to the wakeup fd *after* setting all the globals and
doing the _PyEval_SignalReceived. We used to write to the wakeup fd
Expand Down Expand Up @@ -299,7 +296,7 @@ trip_signal(int sig_num)
{
/* _PyEval_AddPendingCall() isn't signal-safe, but we
still use it for this exceptional case. */
_PyEval_AddPendingCall(tstate,
_PyEval_AddPendingCall(interp,
report_wakeup_send_error,
(void *)(intptr_t) last_error);
}
Expand All @@ -318,7 +315,7 @@ trip_signal(int sig_num)
{
/* _PyEval_AddPendingCall() isn't signal-safe, but we
still use it for this exceptional case. */
_PyEval_AddPendingCall(tstate,
_PyEval_AddPendingCall(interp,
report_wakeup_write_error,
(void *)(intptr_t)errno);
}
Expand Down Expand Up @@ -476,7 +473,7 @@ signal_signal_impl(PyObject *module, int signalnum, PyObject *handler)
#endif

PyThreadState *tstate = _PyThreadState_GET();
if (!_Py_ThreadCanHandleSignals(tstate)) {
if (!_Py_ThreadCanHandleSignals(tstate->interp)) {
_PyErr_SetString(tstate, PyExc_ValueError,
"signal only works in main thread "
"of the main interpreter");
Expand Down Expand Up @@ -704,7 +701,7 @@ signal_set_wakeup_fd(PyObject *self, PyObject *args, PyObject *kwds)
#endif

PyThreadState *tstate = _PyThreadState_GET();
if (!_Py_ThreadCanHandleSignals(tstate)) {
if (!_Py_ThreadCanHandleSignals(tstate->interp)) {
_PyErr_SetString(tstate, PyExc_ValueError,
"set_wakeup_fd only works in main thread "
"of the main interpreter");
Expand Down Expand Up @@ -1681,7 +1678,7 @@ int
PyErr_CheckSignals(void)
{
PyThreadState *tstate = _PyThreadState_GET();
if (!_Py_ThreadCanHandleSignals(tstate)) {
if (!_Py_ThreadCanHandleSignals(tstate->interp)) {
return 0;
}

Expand Down Expand Up @@ -1787,8 +1784,8 @@ PyOS_FiniInterrupts(void)
int
PyOS_InterruptOccurred(void)
{
PyThreadState *tstate = _PyThreadState_GET();
if (!_Py_ThreadCanHandleSignals(tstate)) {
PyInterpreterState *interp = _PyInterpreterState_GET_UNSAFE();
if (!_Py_ThreadCanHandleSignals(interp)) {
return 0;
}

Expand Down Expand Up @@ -1824,8 +1821,8 @@ _PySignal_AfterFork(void)
int
_PyOS_IsMainThread(void)
{
PyThreadState *tstate = _PyThreadState_GET();
return _Py_ThreadCanHandleSignals(tstate);
PyInterpreterState *interp = _PyInterpreterState_GET_UNSAFE();
return _Py_ThreadCanHandleSignals(interp);
}

#ifdef MS_WINDOWS
Expand Down
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