Hide the channels module.

Author: ericsnowcurrently

.github/CODEOWNERS

@@ -284,6 +284,10 @@ Doc/howto/clinic.rst          @erlend-aasland
 Lib/interpreters/             @ericsnowcurrently
 Modules/_interp*module.c      @ericsnowcurrently
 Lib/test/test_interpreters/   @ericsnowcurrently
+Lib/test/test__interp*.py     @ericsnowcurrently
+Lib/test/support/channels.py  @ericsnowcurrently
+Lib/concurrent/futures/interpreter.py  @ericsnowcurrently
+Doc/library/interpreters.rst  @ericsnowcurrently
 
 # Android
 **/*Android*                  @mhsmith @freakboy3742

Lib/interpreters/channels.py renamed to Lib/test/support/channels.py

@@ -2,14 +2,14 @@
 
 import time
 import _interpchannels as _channels
-from . import _crossinterp
+from interpreters import _crossinterp
 
 # aliases:
 from _interpchannels import (
     ChannelError, ChannelNotFoundError, ChannelClosedError,  # noqa: F401
     ChannelEmptyError, ChannelNotEmptyError,  # noqa: F401
 )
-from ._crossinterp import (
+from interpreters._crossinterp import (
     UNBOUND_ERROR, UNBOUND_REMOVE,
 )
 

Lib/test/test_interpreters/test_channels.py

@@ -9,7 +9,7 @@
 # Raise SkipTest if subinterpreters not supported.
 _channels = import_helper.import_module('_interpchannels')
 import interpreters
-from interpreters import channels
+from test.support import channels
 from .utils import _run_output, TestBase
 
 
@@ -171,7 +171,7 @@ def test_send_recv_main(self):
     def test_send_recv_same_interpreter(self):
         interp = interpreters.create()
         interp.exec(dedent("""
-            from interpreters import channels
+            from test.support import channels
             r, s = channels.create()
             orig = b'spam'
             s.send_nowait(orig)
@@ -244,7 +244,7 @@ def test_send_recv_nowait_main_with_default(self):
     def test_send_recv_nowait_same_interpreter(self):
         interp = interpreters.create()
         interp.exec(dedent("""
-            from interpreters import channels
+            from test.support import channels
             r, s = channels.create()
             orig = b'spam'
             s.send_nowait(orig)
@@ -387,7 +387,7 @@ def common(rch, sch, unbound=None, presize=0):
             interp = interpreters.create()
 
             _run_output(interp, dedent(f"""
-                from interpreters import channels
+                from test.support import channels
                 sch = channels.SendChannel({sch.id})
                 obj1 = b'spam'
                 obj2 = b'eggs'
@@ -482,7 +482,7 @@ def test_send_cleared_with_subinterpreter_mixed(self):
         self.assertEqual(_channels.get_count(rch.id), 0)
 
         _run_output(interp, dedent(f"""
-            from interpreters import channels
+            from test.support import channels
             sch = channels.SendChannel({sch.id})
             sch.send_nowait(1, unbounditems=channels.UNBOUND)
             sch.send_nowait(2, unbounditems=channels.UNBOUND_ERROR)
@@ -518,15 +518,15 @@ def test_send_cleared_with_subinterpreter_multiple(self):
 
         sch.send_nowait(1)
         _run_output(interp1, dedent(f"""
-            from interpreters import channels
+            from test.support import channels
             rch = channels.RecvChannel({rch.id})
             sch = channels.SendChannel({sch.id})
             obj1 = rch.recv()
             sch.send_nowait(2, unbounditems=channels.UNBOUND)
             sch.send_nowait(obj1, unbounditems=channels.UNBOUND_REMOVE)
             """))
         _run_output(interp2, dedent(f"""
-            from interpreters import channels
+            from test.support import channels
             rch = channels.RecvChannel({rch.id})
             sch = channels.SendChannel({sch.id})
             obj2 = rch.recv()

Lib/test/test_types.py

@@ -2516,12 +2516,12 @@ def setUpClass(cls):
             import interpreters
         except ModuleNotFoundError:
             raise unittest.SkipTest('subinterpreters required')
-        import interpreters.channels  # noqa: F401
+        import test.support.channels  # noqa: F401
 
     @cpython_only
     @no_rerun('channels (and queues) might have a refleak; see gh-122199')
     def test_static_types_inherited_slots(self):
-        rch, sch = interpreters.channels.create()
+        rch, sch = test.support.channels.create()
 
         script = textwrap.dedent("""
             import test.support

Modules/_interpchannelsmodule.c

@@ -220,6 +220,21 @@ wait_for_lock(PyThread_type_lock mutex, PY_TIMEOUT_T timeout)
     return 0;
 }
 
+static int
+ensure_highlevel_module_loaded(void)
+{
+    PyObject *highlevel = PyImport_ImportModule("interpreters.channels");
+    if (highlevel == NULL) {
+        PyErr_Clear();
+        highlevel = PyImport_ImportModule("test.support.channels");
+        if (highlevel == NULL) {
+            return -1;
+        }
+    }
+    Py_DECREF(highlevel);
+    return 0;
+}
+
 
 /* module state *************************************************************/
 
@@ -2742,11 +2757,9 @@ _get_current_channelend_type(int end)
     }
     if (cls == NULL) {
         // Force the module to be loaded, to register the type.
-        PyObject *highlevel = PyImport_ImportModule("interpreters.channels");
-        if (highlevel == NULL) {
+        if (ensure_highlevel_module_loaded() < 0) {
             return NULL;
         }
-        Py_DECREF(highlevel);
         if (end == CHANNEL_SEND) {
             cls = state->send_channel_type;
         }