From 7b4ba62e388474e811268322b47f80d464933541 Mon Sep 17 00:00:00 2001

From: Victor Stinner <victor.stinner@gmail.com>

Date: Tue, 17 Oct 2017 02:25:23 -0700

Subject: [PATCH] [2.7] bpo-31692: Add PYTHONSHOWALLOCCOUNT env var (GH-3927)

bpo-31692, bpo-19527:

* Add a new PYTHONSHOWALLOCCOUNT environment variable, similar to

  the Python 3 "-X showalloccount" option

* When Python is compiled with COUNT_ALLOCS, the new

  PYTHONSHOWALLOCCOUNT environment variable now has to be set to dump

  allocation counts into stderr on shutdown. Moreover, allocations

  statistics are now dumped into stderr rather than stdout.

* Add @test.support.requires_type_collecting decorator: skip test if

  COUNT_ALLOCS is defined

* Fix tests for COUNT_ALLOCS: decorate some methods with

  @requires_type_collecting

* test_sys.test_objecttypes(): update object type when COUNT_ALLOCS

  is defined

---

 Doc/c-api/typeobj.rst                                              | 2 +-

 Doc/using/cmdline.rst                                              | 7 +++++++

 Lib/test/support/__init__.py                                       | 3 +++

 Lib/test/test_abc.py                                               | 1 +

 Lib/test/test_gc.py                                                | 4 +++-

 Lib/test/test_regrtest.py                                          | 1 +

 Lib/test/test_sys.py                                               | 5 ++++-

 Lib/test/test_weakref.py                                           | 1 +

 .../Core and Builtins/2017-10-09-11-03-13.bpo-31692.5-bpdk.rst     | 4 ++++

 Python/pythonrun.c                                                 | 4 +++-

 10 files changed, 28 insertions(+), 4 deletions(-)

 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2017-10-09-11-03-13.bpo-31692.5-bpdk.rst

diff --git a/Doc/c-api/typeobj.rst b/Doc/c-api/typeobj.rst

index 18edcdd7e5a..f0ccf2ea5fe 100644

--- a/Doc/c-api/typeobj.rst

+++ b/Doc/c-api/typeobj.rst

@@ -1101,7 +1101,7 @@ The next fields, up to and including :c:member:`~PyTypeObject.tp_weaklist`, only

 The remaining fields are only defined if the feature test macro

 :const:`COUNT_ALLOCS` is defined, and are for internal use only. They are

 documented here for completeness.  None of these fields are inherited by

-subtypes.

+subtypes. See the :envvar:`PYTHONSHOWALLOCCOUNT` environment variable.

 .. c:member:: Py_ssize_t PyTypeObject.tp_allocs

diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst

index f00f7f6026a..55bc12893d6 100644

--- a/Doc/using/cmdline.rst

+++ b/Doc/using/cmdline.rst

@@ -663,3 +663,10 @@ if Python was configured with the ``--with-pydebug`` build option.

    If set, Python will print memory allocation statistics every time a new

    object arena is created, and on shutdown.

+

+.. envvar:: PYTHONSHOWALLOCCOUNT

+

+   If set and Python was compiled with ``COUNT_ALLOCS`` defined, Python will

+   dump allocations counts into stderr on shutdown.

+

+   .. versionadded:: 2.7.15

diff --git a/Doc/whatsnew/2.7.rst b/Doc/whatsnew/2.7.rst

index 28a8d4b..f0d2428 100644

--- a/Doc/whatsnew/2.7.rst

+++ b/Doc/whatsnew/2.7.rst

@@ -2540,6 +2540,17 @@ exemption allowing new ``-3`` warnings to be added in any Python 2.7

 maintenance release.

+Two new environment variables for debug mode

+--------------------------------------------

+

+When Python is compiled with ``COUNT_ALLOC`` defined, allocation counts are no

+longer dumped by default anymore: the :envvar:`PYTHONSHOWALLOCCOUNT` environment

+variable must now also be set. Moreover, allocation counts are now dumped into

+stderr, rather than stdout. (Contributed by Victor Stinner; :issue:`31692`.)

+

+.. versionadded:: 2.7.15

+

+

 PEP 434: IDLE Enhancement Exception for All Branches

 ----------------------------------------------------

diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py

index 25df3ed0c41..d14a6620b5d 100644

--- a/Lib/test/support/__init__.py

+++ b/Lib/test/support/__init__.py

@@ -1795,6 +1795,9 @@ def py3k_bytes(b):

         except TypeError:

             return bytes(b)

+requires_type_collecting = unittest.skipIf(hasattr(sys, 'getcounts'),

+                        'types are immortal if COUNT_ALLOCS is defined')

+

 def args_from_interpreter_flags():

     """Return a list of command-line arguments reproducing the current

     settings in sys.flags."""

diff --git a/Lib/test/test_abc.py b/Lib/test/test_abc.py

index 6a8c3a13274..dbba37cdb6f 100644

--- a/Lib/test/test_abc.py

+++ b/Lib/test/test_abc.py

@@ -208,6 +208,7 @@ class C(A, B):

         C()

         self.assertEqual(B.counter, 1)

+    @test_support.requires_type_collecting

     def test_cache_leak(self):

         # See issue #2521.

         class A(object):

diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py

index ed01c9802fc..7e47b2d3a27 100644

--- a/Lib/test/test_gc.py

+++ b/Lib/test/test_gc.py

@@ -1,5 +1,6 @@

 import unittest

-from test.test_support import verbose, run_unittest, start_threads, import_module

+from test.support import (verbose, run_unittest, start_threads, import_module,

+                          requires_type_collecting)

 import sys

 import sysconfig

 import time

@@ -90,6 +91,7 @@ class A:

         del a

         self.assertNotEqual(gc.collect(), 0)

+    @requires_type_collecting

     def test_newinstance(self):

         class A(object):

             pass

diff --git a/Lib/test/test_regrtest.py b/Lib/test/test_regrtest.py

index aae274384c7..988a72c1099 100644

--- a/Lib/test/test_regrtest.py

+++ b/Lib/test/test_regrtest.py

@@ -493,6 +493,7 @@ def check_leak(self, code, what):

             self.assertIn(line2, reflog)

     @unittest.skipUnless(Py_DEBUG, 'need a debug build')

+    @support.requires_type_collecting

     def test_huntrleaks(self):

         # test --huntrleaks

         code = textwrap.dedent("""

diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py

index 5baaa352c0b..9342716272a 100644

--- a/Lib/test/test_sys.py

+++ b/Lib/test/test_sys.py

@@ -748,7 +748,10 @@ def delx(self): del self.__x

         # tupleiterator

         check(iter(()), size('lP'))

         # type

-        s = vsize('P2P15Pl4PP9PP11PI'   # PyTypeObject

+        fmt = 'P2P15Pl4PP9PP11PI'

+        if hasattr(sys, 'getcounts'):

+            fmt += '3P2P'

+        s = vsize(fmt +                 # PyTypeObject

                   '39P'                 # PyNumberMethods

                   '3P'                  # PyMappingMethods

                   '10P'                 # PySequenceMethods

diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py

index 415d5ebbd72..418481dadd8 100644

--- a/Lib/test/test_weakref.py

+++ b/Lib/test/test_weakref.py

@@ -601,6 +601,7 @@ class D:

         del c1, c2, C, D

         gc.collect()

+    @test_support.requires_type_collecting

     def test_callback_in_cycle_resurrection(self):

         import gc

diff --git a/Python/pythonrun.c b/Python/pythonrun.c

index 677f6e48111..44fe13d2f7d 100644

--- a/Python/pythonrun.c

+++ b/Python/pythonrun.c

@@ -488,7 +488,9 @@ Py_Finalize(void)

     /* Debugging stuff */

 #ifdef COUNT_ALLOCS

-    dump_counts(stdout);

+    if (Py_GETENV("PYTHONSHOWALLOCCOUNT")) {

+        dump_counts(stderr);

+    }

 #endif

     PRINT_TOTAL_REFS();