Skip to content

gh-132775: Clean Up Cross-Interpreter Error Handling #135369

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 2 commits into
base: main
Choose a base branch
from
+523 −311
Open

gh-132775: Clean Up Cross-Interpreter Error Handling #135369

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
53123f6
Clean up cross-interpreter error handling.
ericsnowcurrently Jun 10, 2025
738fc6c
fixes
ericsnowcurrently Jun 11, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
37 changes: 20 additions & 17 deletions Include/internal/pycore_crossinterp.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -303,10 +303,10 @@ typedef struct _excinfo {
const char *errdisplay;
} _PyXI_excinfo;

PyAPI_FUNC(int) _PyXI_InitExcInfo(_PyXI_excinfo *info, PyObject *exc);
PyAPI_FUNC(_PyXI_excinfo *) _PyXI_NewExcInfo(PyObject *exc);
PyAPI_FUNC(void) _PyXI_FreeExcInfo(_PyXI_excinfo *info);
PyAPI_FUNC(PyObject *) _PyXI_FormatExcInfo(_PyXI_excinfo *info);
PyAPI_FUNC(PyObject *) _PyXI_ExcInfoAsObject(_PyXI_excinfo *info);
PyAPI_FUNC(void) _PyXI_ClearExcInfo(_PyXI_excinfo *info);


typedef enum error_code {
Expand All @@ -322,19 +322,20 @@ typedef enum error_code {
_PyXI_ERR_NOT_SHAREABLE = -9,
} _PyXI_errcode;

typedef struct xi_failure _PyXI_failure;

typedef struct _sharedexception {
// The originating interpreter.
PyInterpreterState *interp;
// The kind of error to propagate.
_PyXI_errcode code;
// The exception information to propagate, if applicable.
// This is populated only for some error codes,
// but always for _PyXI_ERR_UNCAUGHT_EXCEPTION.
_PyXI_excinfo uncaught;
} _PyXI_error;
PyAPI_FUNC(_PyXI_failure *) _PyXI_NewFailure(void);
PyAPI_FUNC(void) _PyXI_FreeFailure(_PyXI_failure *);
PyAPI_FUNC(_PyXI_errcode) _PyXI_GetFailureCode(_PyXI_failure *);
PyAPI_FUNC(int) _PyXI_InitFailure(_PyXI_failure *, _PyXI_errcode, PyObject *);
PyAPI_FUNC(void) _PyXI_InitFailureUTF8(
_PyXI_failure *,
_PyXI_errcode,
const char *);

PyAPI_FUNC(PyObject *) _PyXI_ApplyError(_PyXI_error *err);
PyAPI_FUNC(int) _PyXI_UnwrapNotShareableError(
PyThreadState *,
_PyXI_failure *);


// A cross-interpreter session involves entering an interpreter
Expand Down Expand Up @@ -366,19 +367,21 @@ PyAPI_FUNC(int) _PyXI_Enter(
_PyXI_session_result *);
PyAPI_FUNC(int) _PyXI_Exit(
_PyXI_session *,
_PyXI_errcode,
_PyXI_failure *,
_PyXI_session_result *);

PyAPI_FUNC(PyObject *) _PyXI_GetMainNamespace(
_PyXI_session *,
_PyXI_errcode *);
_PyXI_failure *);

PyAPI_FUNC(int) _PyXI_Preserve(
_PyXI_session *,
const char *,
PyObject *,
_PyXI_errcode *);
PyAPI_FUNC(PyObject *) _PyXI_GetPreserved(_PyXI_session_result *, const char *);
_PyXI_failure *);
PyAPI_FUNC(PyObject *) _PyXI_GetPreserved(
_PyXI_session_result *,
const char *);


/*************/
Expand Down
90 changes: 52 additions & 38 deletions Modules/_interpretersmodule.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -80,21 +80,11 @@ is_notshareable_raised(PyThreadState *tstate)
}

static void
unwrap_not_shareable(PyThreadState *tstate)
unwrap_not_shareable(PyThreadState *tstate, _PyXI_failure *failure)
{
if (!is_notshareable_raised(tstate)) {
return;
}
PyObject *exc = _PyErr_GetRaisedException(tstate);
PyObject *cause = PyException_GetCause(exc);
if (cause != NULL) {
Py_DECREF(exc);
exc = cause;
if (_PyXI_UnwrapNotShareableError(tstate, failure) < 0) {
_PyErr_Clear(tstate);
}
else {
assert(PyException_GetContext(exc) == NULL);
}
_PyErr_SetRaisedException(tstate, exc);
}


Expand Down Expand Up @@ -532,13 +522,30 @@ _interp_call_pack(PyThreadState *tstate, struct interp_call *call,
return 0;
}

static void
wrap_notshareable(PyThreadState *tstate, const char *label)
{
if (!is_notshareable_raised(tstate)) {
return;
}
assert(label != NULL && strlen(label) > 0);
PyObject *cause = _PyErr_GetRaisedException(tstate);
_PyXIData_FormatNotShareableError(tstate, "%s not shareable", label);
PyObject *exc = _PyErr_GetRaisedException(tstate);
PyException_SetCause(exc, cause);
_PyErr_SetRaisedException(tstate, exc);
}

static int
_interp_call_unpack(struct interp_call *call,
PyObject **p_func, PyObject **p_args, PyObject **p_kwargs)
{
PyThreadState *tstate = PyThreadState_Get();

// Unpack the func.
PyObject *func = _PyXIData_NewObject(call->func);
if (func == NULL) {
wrap_notshareable(tstate, "func");
return -1;
}
// Unpack the args.
Expand All @@ -553,6 +560,7 @@ _interp_call_unpack(struct interp_call *call,
else {
args = _PyXIData_NewObject(call->args);
if (args == NULL) {
wrap_notshareable(tstate, "args");
Py_DECREF(func);
return -1;
}
Expand All @@ -563,6 +571,7 @@ _interp_call_unpack(struct interp_call *call,
if (call->kwargs != NULL) {
kwargs = _PyXIData_NewObject(call->kwargs);
if (kwargs == NULL) {
wrap_notshareable(tstate, "kwargs");
Py_DECREF(func);
Py_DECREF(args);
return -1;
Expand All @@ -577,7 +586,7 @@ _interp_call_unpack(struct interp_call *call,

static int
_make_call(struct interp_call *call,
PyObject **p_result, _PyXI_errcode *p_errcode)
PyObject **p_result, _PyXI_failure *failure)
{
assert(call != NULL && call->func != NULL);
PyThreadState *tstate = _PyThreadState_GET();
Expand All @@ -588,12 +597,10 @@ _make_call(struct interp_call *call,
assert(func == NULL);
assert(args == NULL);
assert(kwargs == NULL);
*p_errcode = is_notshareable_raised(tstate)
? _PyXI_ERR_NOT_SHAREABLE
: _PyXI_ERR_OTHER;
_PyXI_InitFailure(failure, _PyXI_ERR_OTHER, NULL);
unwrap_not_shareable(tstate, failure);
return -1;
}
*p_errcode = _PyXI_ERR_NO_ERROR;

// Make the call.
PyObject *resobj = PyObject_Call(func, args, kwargs);
Expand All @@ -608,17 +615,17 @@ _make_call(struct interp_call *call,
}

static int
_run_script(_PyXIData_t *script, PyObject *ns, _PyXI_errcode *p_errcode)
_run_script(_PyXIData_t *script, PyObject *ns, _PyXI_failure *failure)
{
PyObject *code = _PyXIData_NewObject(script);
if (code == NULL) {
*p_errcode = _PyXI_ERR_NOT_SHAREABLE;
_PyXI_InitFailure(failure, _PyXI_ERR_NOT_SHAREABLE, NULL);
return -1;
}
PyObject *result = PyEval_EvalCode(code, ns, ns);
Py_DECREF(code);
if (result == NULL) {
*p_errcode = _PyXI_ERR_UNCAUGHT_EXCEPTION;
_PyXI_InitFailure(failure, _PyXI_ERR_UNCAUGHT_EXCEPTION, NULL);
return -1;
}
assert(result == Py_None);
Expand All @@ -644,8 +651,14 @@ _run_in_interpreter(PyThreadState *tstate, PyInterpreterState *interp,
PyObject *shareables, struct run_result *runres)
{
assert(!_PyErr_Occurred(tstate));
int res = -1;
_PyXI_failure *failure = _PyXI_NewFailure();
if (failure == NULL) {
return -1;
}
_PyXI_session *session = _PyXI_NewSession();
if (session == NULL) {
_PyXI_FreeFailure(failure);
return -1;
}
_PyXI_session_result result = {0};
Expand All @@ -655,43 +668,44 @@ _run_in_interpreter(PyThreadState *tstate, PyInterpreterState *interp,
// If an error occured at this step, it means that interp
// was not prepared and switched.
_PyXI_FreeSession(session);
_PyXI_FreeFailure(failure);
assert(result.excinfo == NULL);
return -1;
}

// Run in the interpreter.
int res = -1;
_PyXI_errcode errcode = _PyXI_ERR_NO_ERROR;
if (script != NULL) {
assert(call == NULL);
PyObject *mainns = _PyXI_GetMainNamespace(session, &errcode);
PyObject *mainns = _PyXI_GetMainNamespace(session, failure);
if (mainns == NULL) {
goto finally;
}
res = _run_script(script, mainns, &errcode);
res = _run_script(script, mainns, failure);
}
else {
assert(call != NULL);
PyObject *resobj;
res = _make_call(call, &resobj, &errcode);
res = _make_call(call, &resobj, failure);
if (res == 0) {
res = _PyXI_Preserve(session, "resobj", resobj, &errcode);
res = _PyXI_Preserve(session, "resobj", resobj, failure);
Py_DECREF(resobj);
if (res < 0) {
goto finally;
}
}
}
int exitres;

finally:
// Clean up and switch back.
exitres = _PyXI_Exit(session, errcode, &result);
(void)res;
int exitres = _PyXI_Exit(session, failure, &result);
assert(res == 0 || exitres != 0);
_PyXI_FreeSession(session);
_PyXI_FreeFailure(failure);

res = exitres;
if (_PyErr_Occurred(tstate)) {
// It's a directly propagated exception.
assert(res < 0);
}
else if (res < 0) {
Expand Down Expand Up @@ -1064,7 +1078,7 @@ interp_set___main___attrs(PyObject *self, PyObject *args, PyObject *kwargs)

// Clean up and switch back.
assert(!PyErr_Occurred());
int res = _PyXI_Exit(session, _PyXI_ERR_NO_ERROR, NULL);
int res = _PyXI_Exit(session, NULL, NULL);
_PyXI_FreeSession(session);
assert(res == 0);
if (res < 0) {
Expand Down Expand Up @@ -1124,7 +1138,7 @@ interp_exec(PyObject *self, PyObject *args, PyObject *kwds)
// global variables. They will be resolved against __main__.
_PyXIData_t xidata = {0};
if (_PyCode_GetScriptXIData(tstate, code, &xidata) < 0) {
unwrap_not_shareable(tstate);
unwrap_not_shareable(tstate, NULL);
return NULL;
}

Expand Down Expand Up @@ -1188,7 +1202,7 @@ interp_run_string(PyObject *self, PyObject *args, PyObject *kwds)

_PyXIData_t xidata = {0};
if (_PyCode_GetScriptXIData(tstate, script, &xidata) < 0) {
unwrap_not_shareable(tstate);
unwrap_not_shareable(tstate, NULL);
return NULL;
}

Expand Down Expand Up @@ -1251,7 +1265,7 @@ interp_run_func(PyObject *self, PyObject *args, PyObject *kwds)

_PyXIData_t xidata = {0};
if (_PyCode_GetScriptXIData(tstate, code, &xidata) < 0) {
unwrap_not_shareable(tstate);
unwrap_not_shareable(tstate, NULL);
return NULL;
}

Expand Down Expand Up @@ -1542,16 +1556,16 @@ capture_exception(PyObject *self, PyObject *args, PyObject *kwds)
}
PyObject *captured = NULL;

_PyXI_excinfo info = {0};
if (_PyXI_InitExcInfo(&info, exc) < 0) {
_PyXI_excinfo *info = _PyXI_NewExcInfo(exc);
if (info == NULL) {
goto finally;
}
captured = _PyXI_ExcInfoAsObject(&info);
captured = _PyXI_ExcInfoAsObject(info);
if (captured == NULL) {
goto finally;
}

PyObject *formatted = _PyXI_FormatExcInfo(&info);
PyObject *formatted = _PyXI_FormatExcInfo(info);
if (formatted == NULL) {
Py_CLEAR(captured);
goto finally;
Expand All @@ -1564,7 +1578,7 @@ capture_exception(PyObject *self, PyObject *args, PyObject *kwds)
}

finally:
_PyXI_ClearExcInfo(&info);
_PyXI_FreeExcInfo(info);
if (exc != exc_arg) {
if (PyErr_Occurred()) {
PyErr_SetRaisedException(exc);
Expand Down
Loading
Loading