gh-76785: Add Interpreter.bind()

Include/internal/pycore_crossinterp.h

@@ -164,17 +164,6 @@ extern void _PyXI_Fini(PyInterpreterState *interp);
 /* short-term data sharing */
 /***************************/
 
-// Ultimately we'd like to preserve enough information about the
-// exception and traceback that we could re-constitute (or at least
-// simulate, a la traceback.TracebackException), and even chain, a copy
-// of the exception in the calling interpreter.
-
-typedef struct _excinfo {
-    const char *type;
-    const char *msg;
-} _Py_excinfo;
-
-
 typedef enum error_code {
     _PyXI_ERR_NO_ERROR = 0,
     _PyXI_ERR_UNCAUGHT_EXCEPTION = -1,
@@ -197,9 +186,6 @@ typedef struct _sharedexception {
     _Py_excinfo uncaught;
 } _PyXI_exception_info;
 
-PyAPI_FUNC(void) _PyXI_ApplyExceptionInfo(
-    _PyXI_exception_info *info,
-    PyObject *exctype);
 
 typedef struct xi_session _PyXI_session;
 typedef struct _sharedns _PyXI_namespace;
@@ -269,6 +255,9 @@ PyAPI_FUNC(void) _PyXI_Exit(_PyXI_session *session);
 PyAPI_FUNC(void) _PyXI_ApplyCapturedException(
     _PyXI_session *session,
     PyObject *excwrapper);
+PyAPI_FUNC(PyObject *) _PyXI_ResolveCapturedException(
+    _PyXI_session *session,
+    PyObject *excwrapper);
 PyAPI_FUNC(int) _PyXI_HasCapturedException(_PyXI_session *session);
 
 

Include/internal/pycore_exceptions.h

@@ -8,16 +8,20 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
+#include "pycore_pyerrors.h"
+
 
 /* runtime lifecycle */
 
 extern PyStatus _PyExc_InitState(PyInterpreterState *);
 extern PyStatus _PyExc_InitGlobalObjects(PyInterpreterState *);
 extern int _PyExc_InitTypes(PyInterpreterState *);
+extern void _PyExc_FiniHeapObjects(PyInterpreterState *);
+extern void _PyExc_FiniTypes(PyInterpreterState *);
 extern void _PyExc_Fini(PyInterpreterState *);
 
 
-/* other API */
+/* runtime state */
 
 struct _Py_exc_state {
     // The dict mapping from errno codes to OSError subclasses
@@ -26,9 +30,17 @@ struct _Py_exc_state {
     int memerrors_numfree;
     // The ExceptionGroup type
     PyObject *PyExc_ExceptionGroup;
+
+    PyTypeObject *ExceptionSnapshotType;
 };
 
-extern void _PyExc_ClearExceptionGroupType(PyInterpreterState *);
+
+/* other API */
+
+PyAPI_FUNC(PyTypeObject *) _PyExc_GetExceptionSnapshotType(
+    PyInterpreterState *interp);
+
+extern PyObject * PyExceptionSnapshot_FromInfo(_Py_excinfo *info);
 
 
 #ifdef __cplusplus

Include/internal/pycore_pyerrors.h

@@ -68,6 +68,30 @@ extern PyStatus _PyErr_InitTypes(PyInterpreterState *);
 extern void _PyErr_FiniTypes(PyInterpreterState *);
 
 
+/* exception snapshots */
+
+// Ultimately we'd like to preserve enough information about the
+// exception and traceback that we could re-constitute (or at least
+// simulate, a la traceback.TracebackException), and even chain, a copy
+// of the exception in the calling interpreter.
+
+typedef struct _excinfo {
+    const char *type;
+    const char *msg;
+} _Py_excinfo;
+
+extern void _Py_excinfo_Clear(_Py_excinfo *info);
+extern int _Py_excinfo_Copy(_Py_excinfo *dest, _Py_excinfo *src);
+extern const char * _Py_excinfo_InitFromException(
+    _Py_excinfo *info,
+    PyObject *exc);
+extern void _Py_excinfo_Apply(_Py_excinfo *info, PyObject *exctype);
+extern const char * _Py_excinfo_AsUTF8(
+    _Py_excinfo *info,
+    char *buf,
+    size_t bufsize);
+
+
 /* other API */
 
 static inline PyObject* _PyErr_Occurred(PyThreadState *tstate)

Lib/test/support/interpreters.py

@@ -14,13 +14,25 @@
 
 __all__ = [
     'Interpreter', 'get_current', 'get_main', 'create', 'list_all',
+    'RunFailedError',
     'SendChannel', 'RecvChannel',
     'create_channel', 'list_all_channels', 'is_shareable',
     'ChannelError', 'ChannelNotFoundError',
     'ChannelEmptyError',
     ]
 
 
+class RunFailedError(RuntimeError):
+
+    def __init__(self, snapshot):
+        if snapshot.type and snapshot.msg:
+            msg = f'{snapshot.type}: {snapshot.msg}'
+        else:
+            msg = snapshot.type or snapshot.msg
+        super().__init__(msg)
+        self.snapshot = snapshot
+
+
 def create(*, isolated=True):
     """Return a new (idle) Python interpreter."""
     id = _interpreters.create(isolated=isolated)
@@ -91,14 +103,39 @@ def close(self):
         """
         return _interpreters.destroy(self._id)
 
+    # XXX setattr?
+    def bind(self, ns=None, /, **kwargs):
+        """Bind the given values into the interpreter's __main__.
+
+        The values must be shareable.
+        """
+        ns = dict(ns, **kwargs) if ns is not None else kwargs
+        _interpreters.set___main___attrs(self._id, ns)
+
+    # XXX getattr?
+    def get(self, name, default=None, /):
+        """Return the attr value from the interpreter's __main__.
+
+        The value must be shareable.
+        """
+        found = _interpreters.get___main___attrs(self._id, (name,), default)
+        assert len(found) == 1, found
+        return found[name]
+
     # XXX Rename "run" to "exec"?
-    def run(self, src_str, /, channels=None):
+    # XXX Do not allow init to overwrite (by default)?
+    def run(self, src_str, /, *, init=None):
         """Run the given source code in the interpreter.
 
         This is essentially the same as calling the builtin "exec"
         with this interpreter, using the __dict__ of its __main__
         module as both globals and locals.
 
+        If "init" is provided, it must be a dict mapping attribute names
+        to "shareable" objects, including channels.  These are set as
+        attributes on the __main__ module before the given code is
+        executed.  If a name is already bound then it is overwritten.
+
         There is no return value.
 
         If the code raises an unhandled exception then a RunFailedError
@@ -110,7 +147,9 @@ def run(self, src_str, /, channels=None):
         that time, the previous interpreter is allowed to run
         in other threads.
         """
-        _interpreters.exec(self._id, src_str, channels)
+        err = _interpreters.exec(self._id, src_str, init)
+        if err is not None:
+            raise RunFailedError(err)
 
 
 def create_channel():

Lib/test/test__xxinterpchannels.py

@@ -587,12 +587,12 @@ def test_run_string_arg_unresolved(self):
         cid = channels.create()
         interp = interpreters.create()
 
+        interpreters.set___main___attrs(interp, dict(cid=cid.send))
         out = _run_output(interp, dedent("""
             import _xxinterpchannels as _channels
             print(cid.end)
             _channels.send(cid, b'spam', blocking=False)
-            """),
-            dict(cid=cid.send))
+            """))
         obj = channels.recv(cid)
 
         self.assertEqual(obj, b'spam')
@@ -1017,16 +1017,16 @@ def test_close_multiple_users(self):
             _channels.recv({cid})
             """))
         channels.close(cid)
-        with self.assertRaises(interpreters.RunFailedError) as cm:
-            interpreters.run_string(id1, dedent(f"""
+
+        excsnap = interpreters.run_string(id1, dedent(f"""
                 _channels.send({cid}, b'spam')
                 """))
-        self.assertIn('ChannelClosedError', str(cm.exception))
-        with self.assertRaises(interpreters.RunFailedError) as cm:
-            interpreters.run_string(id2, dedent(f"""
+        self.assertIn('ChannelClosedError', excsnap.type)
+
+        excsnap = interpreters.run_string(id2, dedent(f"""
                 _channels.send({cid}, b'spam')
                 """))
-        self.assertIn('ChannelClosedError', str(cm.exception))
+        self.assertIn('ChannelClosedError', excsnap.type)
 
     def test_close_multiple_times(self):
         cid = channels.create()

Lib/test/test__xxsubinterpreters.py

@@ -31,10 +31,10 @@ def _captured_script(script):
     return wrapped, open(r, encoding="utf-8")
 
 
-def _run_output(interp, request, shared=None):
+def _run_output(interp, request):
     script, rpipe = _captured_script(request)
     with rpipe:
-        interpreters.run_string(interp, script, shared)
+        interpreters.run_string(interp, script)
         return rpipe.read()
 
 
@@ -659,10 +659,10 @@ def test_shareable_types(self):
         ]
         for obj in objects:
             with self.subTest(obj):
+                interpreters.set___main___attrs(interp, dict(obj=obj))
                 interpreters.run_string(
                     interp,
                     f'assert(obj == {obj!r})',
-                    shared=dict(obj=obj),
                 )
 
     def test_os_exec(self):
@@ -743,30 +743,33 @@ def assert_run_failed(self, exctype, msg=None):
                              "{}: {}".format(exctype.__name__, msg))
 
     def test_invalid_syntax(self):
-        with self.assert_run_failed(SyntaxError):
-            # missing close paren
-            interpreters.run_string(self.id, 'print("spam"')
+        # missing close paren
+        exc = interpreters.run_string(self.id, 'print("spam"')
+        self.assertEqual(exc.type, 'SyntaxError')
 
     def test_failure(self):
-        with self.assert_run_failed(Exception, 'spam'):
-            interpreters.run_string(self.id, 'raise Exception("spam")')
+        exc = interpreters.run_string(self.id, 'raise Exception("spam")')
+        self.assertEqual(exc.type, 'Exception')
+        self.assertEqual(exc.msg, 'spam')
 
     def test_SystemExit(self):
-        with self.assert_run_failed(SystemExit, '42'):
-            interpreters.run_string(self.id, 'raise SystemExit(42)')
+        exc = interpreters.run_string(self.id, 'raise SystemExit(42)')
+        self.assertEqual(exc.type, 'SystemExit')
+        self.assertEqual(exc.msg, '42')
 
     def test_sys_exit(self):
-        with self.assert_run_failed(SystemExit):
-            interpreters.run_string(self.id, dedent("""
-                import sys
-                sys.exit()
-                """))
+        exc = interpreters.run_string(self.id, dedent("""
+            import sys
+            sys.exit()
+            """))
+        self.assertEqual(exc.type, 'SystemExit')
 
-        with self.assert_run_failed(SystemExit, '42'):
-            interpreters.run_string(self.id, dedent("""
-                import sys
-                sys.exit(42)
-                """))
+        exc = interpreters.run_string(self.id, dedent("""
+            import sys
+            sys.exit(42)
+            """))
+        self.assertEqual(exc.type, 'SystemExit')
+        self.assertEqual(exc.msg, '42')
 
     def test_with_shared(self):
         r, w = os.pipe()
@@ -787,7 +790,8 @@ def test_with_shared(self):
             with open({w}, 'wb') as chan:
                 pickle.dump(ns, chan)
             """)
-        interpreters.run_string(self.id, script, shared)
+        interpreters.set___main___attrs(self.id, shared)
+        interpreters.run_string(self.id, script)
         with open(r, 'rb') as chan:
             ns = pickle.load(chan)
 
@@ -808,7 +812,8 @@ def test_shared_overwrites(self):
             ns2 = dict(vars())
             del ns2['__builtins__']
         """)
-        interpreters.run_string(self.id, script, shared)
+        interpreters.set___main___attrs(self.id, shared)
+        interpreters.run_string(self.id, script)
 
         r, w = os.pipe()
         script = dedent(f"""
@@ -839,7 +844,8 @@ def test_shared_overwrites_default_vars(self):
             with open({w}, 'wb') as chan:
                 pickle.dump(ns, chan)
             """)
-        interpreters.run_string(self.id, script, shared)
+        interpreters.set___main___attrs(self.id, shared)
+        interpreters.run_string(self.id, script)
         with open(r, 'rb') as chan:
             ns = pickle.load(chan)
 
@@ -945,7 +951,8 @@ def script():
             with open(w, 'w', encoding="utf-8") as spipe:
                 with contextlib.redirect_stdout(spipe):
                     print('it worked!', end='')
-        interpreters.run_func(self.id, script, shared=dict(w=w))
+        interpreters.set___main___attrs(self.id, dict(w=w))
+        interpreters.run_func(self.id, script)
 
         with open(r, encoding="utf-8") as outfile:
             out = outfile.read()
@@ -961,7 +968,8 @@ def script():
                 with contextlib.redirect_stdout(spipe):
                     print('it worked!', end='')
         def f():
-            interpreters.run_func(self.id, script, shared=dict(w=w))
+            interpreters.set___main___attrs(self.id, dict(w=w))
+            interpreters.run_func(self.id, script)
         t = threading.Thread(target=f)
         t.start()
         t.join()
@@ -981,7 +989,8 @@ def script():
                 with contextlib.redirect_stdout(spipe):
                     print('it worked!', end='')
         code = script.__code__
-        interpreters.run_func(self.id, code, shared=dict(w=w))
+        interpreters.set___main___attrs(self.id, dict(w=w))
+        interpreters.run_func(self.id, code)
 
         with open(r, encoding="utf-8") as outfile:
             out = outfile.read()

Lib/test/test_import/__init__.py

@@ -1968,10 +1968,12 @@ def test_disallowed_reimport(self):
             print(_testsinglephase)
             ''')
         interpid = _interpreters.create()
-        with self.assertRaises(_interpreters.RunFailedError):
-            _interpreters.run_string(interpid, script)
-        with self.assertRaises(_interpreters.RunFailedError):
-            _interpreters.run_string(interpid, script)
+
+        excsnap = _interpreters.run_string(interpid, script)
+        self.assertIsNot(excsnap, None)
+
+        excsnap = _interpreters.run_string(interpid, script)
+        self.assertIsNot(excsnap, None)
 
 
 class TestSinglePhaseSnapshot(ModuleSnapshot):