bpo-31009: Fix support.fd_count() on Windows (#2862)

* bpo-31009: Fix support.fd_count() on Windows

On Windows, test.support.fd_count() now calls
msvcrt.CrtSetReportMode() to not kill the process nor log any error
on stderr on os.dup(fd) if the file descriptor is invalid.

* Fix for release mode
This commit is contained in:
Victor Stinner 2017-07-25 17:45:53 +02:00 committed by GitHub
parent 90addd6d1c
commit 302bbbe9ba
2 changed files with 43 additions and 29 deletions

View File

@ -2649,12 +2649,6 @@ def disable_faulthandler():
faulthandler.enable(file=fd, all_threads=True)
try:
MAXFD = os.sysconf("SC_OPEN_MAX")
except Exception:
MAXFD = 256
def fd_count():
"""Count the number of open file descriptors.
"""
@ -2665,16 +2659,48 @@ def fd_count():
except FileNotFoundError:
pass
count = 0
for fd in range(MAXFD):
old_modes = None
if sys.platform == 'win32':
# bpo-25306, bpo-31009: Call CrtSetReportMode() to not kill the process
# on invalid file descriptor if Python is compiled in debug mode
try:
# Prefer dup() over fstat(). fstat() can require input/output
# whereas dup() doesn't.
fd2 = os.dup(fd)
except OSError as e:
if e.errno != errno.EBADF:
raise
import msvcrt
msvcrt.CrtSetReportMode
except (AttributeError, ImportError):
# no msvcrt or a release build
pass
else:
os.close(fd2)
count += 1
old_modes = {}
for report_type in (msvcrt.CRT_WARN,
msvcrt.CRT_ERROR,
msvcrt.CRT_ASSERT):
old_modes[report_type] = msvcrt.CrtSetReportMode(report_type, 0)
MAXFD = 256
if hasattr(os, 'sysconf'):
try:
MAXFD = os.sysconf("SC_OPEN_MAX")
except OSError:
pass
try:
count = 0
for fd in range(MAXFD):
try:
# Prefer dup() over fstat(). fstat() can require input/output
# whereas dup() doesn't.
fd2 = os.dup(fd)
except OSError as e:
if e.errno != errno.EBADF:
raise
else:
os.close(fd2)
count += 1
finally:
if old_modes is not None:
for report_type in (msvcrt.CRT_WARN,
msvcrt.CRT_ERROR,
msvcrt.CRT_ASSERT):
msvcrt.CrtSetReportMode(report_type, old_modes[report_type])
return count

View File

@ -835,22 +835,10 @@ class ArgsTestCase(BaseTestCase):
import os
import unittest
# Issue #25306: Disable popups and logs to stderr on assertion
# failures in MSCRT
try:
import msvcrt
msvcrt.CrtSetReportMode
except (ImportError, AttributeError):
# no Windows, o release build
pass
else:
for m in [msvcrt.CRT_WARN, msvcrt.CRT_ERROR, msvcrt.CRT_ASSERT]:
msvcrt.CrtSetReportMode(m, 0)
class FDLeakTest(unittest.TestCase):
def test_leak(self):
fd = os.open(__file__, os.O_RDONLY)
# bug: never cloes the file descriptor
# bug: never close the file descriptor
""")
self.check_leak(code, 'file descriptors')