gh-76785: Add Interpreter.prepare_main() (gh-113021)

This is one of the last pieces to get test.support.interpreters in sync with PEP 734.

1 files changed, 12 insertions, 4 deletions

diff --git a/Lib/test/support/interpreters/__init__.py b/Lib/test/support/interpreters/__init__.py
index 2d6376d..9cd1c3d 100644
--- a/Lib/test/support/interpreters/__init__.py
+++ b/Lib/test/support/interpreters/__init__.py
@@ -130,7 +130,15 @@ class Interpreter:
         """
         return _interpreters.destroy(self._id)
 
-    def exec_sync(self, code, /, channels=None):
+    def prepare_main(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)
+
+    def exec_sync(self, code, /):
         """Run the given source code in the interpreter.
 
         This is essentially the same as calling the builtin "exec"
@@ -148,13 +156,13 @@ class Interpreter:
         that time, the previous interpreter is allowed to run
         in other threads.
         """
-        excinfo = _interpreters.exec(self._id, code, channels)
+        excinfo = _interpreters.exec(self._id, code)
         if excinfo is not None:
             raise ExecFailure(excinfo)
 
-    def run(self, code, /, channels=None):
+    def run(self, code, /):
         def task():
-            self.exec_sync(code, channels=channels)
+            self.exec_sync(code)
         t = threading.Thread(target=task)
         t.start()
         return t