bpo-29102: Add a unique ID to PyInterpreterState. (#1639)
diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst
index 56cf77a..ca7636b 100644
--- a/Doc/c-api/init.rst
+++ b/Doc/c-api/init.rst
@@ -821,6 +821,14 @@
:c:func:`PyThreadState_Clear`.
+.. c:function:: PY_INT64_T PyInterpreterState_GetID(PyInterpreterState *interp)
+
+ Return the interpreter's unique ID. If there was any error in doing
+ so then -1 is returned and an error is set.
+
+ .. versionadded:: 3.7
+
+
.. c:function:: PyObject* PyThreadState_GetDict()
Return a dictionary in which extensions can store thread-specific state
diff --git a/Include/pystate.h b/Include/pystate.h
index 62254fa..9170ba9 100644
--- a/Include/pystate.h
+++ b/Include/pystate.h
@@ -28,6 +28,8 @@
struct _is *next;
struct _ts *tstate_head;
+ int64_t id;
+
PyObject *modules;
PyObject *modules_by_index;
PyObject *sysdict;
@@ -154,9 +156,16 @@
#endif
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(void) _PyInterpreterState_Init(void);
+#endif /* !Py_LIMITED_API */
PyAPI_FUNC(PyInterpreterState *) PyInterpreterState_New(void);
PyAPI_FUNC(void) PyInterpreterState_Clear(PyInterpreterState *);
PyAPI_FUNC(void) PyInterpreterState_Delete(PyInterpreterState *);
+#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03070000
+/* New in 3.7 */
+PyAPI_FUNC(int64_t) PyInterpreterState_GetID(PyInterpreterState *);
+#endif
#ifndef Py_LIMITED_API
PyAPI_FUNC(int) _PyState_AddModule(PyObject*, struct PyModuleDef*);
#endif /* !Py_LIMITED_API */
diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index eb3e2c5..7660981 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -1,8 +1,10 @@
# Run the _testcapi module tests (tests for the Python/C API): by defn,
# these are all functions _testcapi exports whose name begins with 'test_'.
+from collections import namedtuple
import os
import pickle
+import platform
import random
import re
import subprocess
@@ -384,12 +386,91 @@
return out, err
def test_subinterps(self):
- # This is just a "don't crash" test
out, err = self.run_embedded_interpreter("repeated_init_and_subinterpreters")
- if support.verbose:
- print()
- print(out)
- print(err)
+ self.assertEqual(err, "")
+
+ # The output from _testembed looks like this:
+ # --- Pass 0 ---
+ # interp 0 <0x1cf9330>, thread state <0x1cf9700>: id(modules) = 139650431942728
+ # interp 1 <0x1d4f690>, thread state <0x1d35350>: id(modules) = 139650431165784
+ # interp 2 <0x1d5a690>, thread state <0x1d99ed0>: id(modules) = 139650413140368
+ # interp 3 <0x1d4f690>, thread state <0x1dc3340>: id(modules) = 139650412862200
+ # interp 0 <0x1cf9330>, thread state <0x1cf9700>: id(modules) = 139650431942728
+ # --- Pass 1 ---
+ # ...
+
+ interp_pat = (r"^interp (\d+) <(0x[\dA-F]+)>, "
+ r"thread state <(0x[\dA-F]+)>: "
+ r"id\(modules\) = ([\d]+)$")
+ Interp = namedtuple("Interp", "id interp tstate modules")
+
+ main = None
+ lastmain = None
+ numinner = None
+ numloops = 0
+ for line in out.splitlines():
+ if line == "--- Pass {} ---".format(numloops):
+ if numinner is not None:
+ self.assertEqual(numinner, 5)
+ if support.verbose:
+ print(line)
+ lastmain = main
+ main = None
+ mainid = 0
+ numloops += 1
+ numinner = 0
+ continue
+ numinner += 1
+
+ self.assertLessEqual(numinner, 5)
+ match = re.match(interp_pat, line)
+ if match is None:
+ self.assertRegex(line, interp_pat)
+
+ # The last line in the loop should be the same as the first.
+ if numinner == 5:
+ self.assertEqual(match.groups(), main)
+ continue
+
+ # Parse the line from the loop. The first line is the main
+ # interpreter and the 3 afterward are subinterpreters.
+ interp = Interp(*match.groups())
+ if support.verbose:
+ print(interp)
+ if numinner == 1:
+ main = interp
+ id = str(mainid)
+ else:
+ subid = mainid + numinner - 1
+ id = str(subid)
+
+ # Validate the loop line for each interpreter.
+ self.assertEqual(interp.id, id)
+ self.assertTrue(interp.interp)
+ self.assertTrue(interp.tstate)
+ self.assertTrue(interp.modules)
+ if platform.system() == 'Windows':
+ # XXX Fix on Windows: something is going on with the
+ # pointers in Programs/_testembed.c. interp.interp
+ # is 0x0 and # interp.modules is the same between
+ # interpreters.
+ continue
+ if interp is main:
+ if lastmain is not None:
+ # A new main interpreter may have the same interp
+ # and/or tstate pointer as an earlier finalized/
+ # destroyed one. So we do not check interp or
+ # tstate here.
+ self.assertNotEqual(interp.modules, lastmain.modules)
+ else:
+ # A new subinterpreter may have the same
+ # PyInterpreterState pointer as a previous one if
+ # the earlier one has already been destroyed. So
+ # we compare with the main interpreter. The same
+ # applies to tstate.
+ self.assertNotEqual(interp.interp, main.interp)
+ self.assertNotEqual(interp.tstate, main.tstate)
+ self.assertNotEqual(interp.modules, main.modules)
@staticmethod
def _get_default_pipe_encoding():
diff --git a/Misc/NEWS b/Misc/NEWS
index 34f1c15..5b41dcf 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -53,6 +53,9 @@
- bpo-24821: Fixed the slowing down to 25 times in the searching of some
unlucky Unicode characters.
+- bpo-29102: Add a unique ID to PyInterpreterState. This makes it easier
+ to identify each subinterpreter.
+
- bpo-29894: The deprecation warning is emitted if __complex__ returns an
instance of a strict subclass of complex. In a future versions of Python
this can be an error.
diff --git a/PC/python3.def b/PC/python3.def
index bb3ca88..ad65294 100644
--- a/PC/python3.def
+++ b/PC/python3.def
@@ -538,6 +538,7 @@
PySlice_Type=python37.PySlice_Type DATA
PySlice_Unpack=python37.PySlice_Unpack
PySortWrapper_Type=python37.PySortWrapper_Type DATA
+ PyInterpreterState_GetID=python37.PyInterpreterState_GetID
PyState_AddModule=python37.PyState_AddModule
PyState_FindModule=python37.PyState_FindModule
PyState_RemoveModule=python37.PyState_RemoveModule
diff --git a/Programs/_testembed.c b/Programs/_testembed.c
index a68d4fa..de88404 100644
--- a/Programs/_testembed.c
+++ b/Programs/_testembed.c
@@ -1,4 +1,5 @@
#include <Python.h>
+#include <inttypes.h>
#include <stdio.h>
/*********************************************************
@@ -22,9 +23,13 @@
static void print_subinterp(void)
{
- /* Just output some debug stuff */
+ /* Output information about the interpreter in the format
+ expected in Lib/test/test_capi.py (test_subinterps). */
PyThreadState *ts = PyThreadState_Get();
- printf("interp %p, thread state %p: ", ts->interp, ts);
+ PyInterpreterState *interp = ts->interp;
+ int64_t id = PyInterpreterState_GetID(interp);
+ printf("interp %lu <0x%" PRIXPTR ">, thread state <0x%" PRIXPTR ">: ",
+ id, (uintptr_t)interp, (uintptr_t)ts);
fflush(stdout);
PyRun_SimpleString(
"import sys;"
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index c0f41b3..90f8551 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -344,6 +344,7 @@
_PyRandom_Init();
+ _PyInterpreterState_Init();
interp = PyInterpreterState_New();
if (interp == NULL)
Py_FatalError("Py_Initialize: can't make first interpreter");
diff --git a/Python/pystate.c b/Python/pystate.c
index 52899f1..99a579a 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -65,6 +65,23 @@
static void _PyGILState_NoteThreadState(PyThreadState* tstate);
#endif
+/* _next_interp_id is an auto-numbered sequence of small integers.
+ It gets initialized in _PyInterpreterState_Init(), which is called
+ in Py_Initialize(), and used in PyInterpreterState_New(). A negative
+ interpreter ID indicates an error occurred. The main interpreter
+ will always have an ID of 0. Overflow results in a RuntimeError.
+ If that becomes a problem later then we can adjust, e.g. by using
+ a Python int.
+
+ We initialize this to -1 so that the pre-Py_Initialize() value
+ results in an error. */
+static int64_t _next_interp_id = -1;
+
+void
+_PyInterpreterState_Init(void)
+{
+ _next_interp_id = 0;
+}
PyInterpreterState *
PyInterpreterState_New(void)
@@ -103,6 +120,15 @@
HEAD_LOCK();
interp->next = interp_head;
interp_head = interp;
+ if (_next_interp_id < 0) {
+ /* overflow or Py_Initialize() not called! */
+ PyErr_SetString(PyExc_RuntimeError,
+ "failed to get an interpreter ID");
+ interp = NULL;
+ } else {
+ interp->id = _next_interp_id;
+ _next_interp_id += 1;
+ }
HEAD_UNLOCK();
}
@@ -170,6 +196,17 @@
}
+int64_t
+PyInterpreterState_GetID(PyInterpreterState *interp)
+{
+ if (interp == NULL) {
+ PyErr_SetString(PyExc_RuntimeError, "no interpreter provided");
+ return -1;
+ }
+ return interp->id;
+}
+
+
/* Default implementation for _PyThreadState_GetFrame */
static struct _frame *
threadstate_getframe(PyThreadState *self)