Skip to content

C
cpython
Commit 3a4586a9 authored by Charles-François Natali's avatar Charles-François Natali
Browse files
Options

Issue #18923: Update subprocess to use the new selectors module.

parent 2ce6c44a
Hide whitespace changes
Inline Side-by-side
Showing with 75 additions and 173 deletions
Lib/subprocess.py
View file @ 3a4586a9
......@@ -404,15 +404,23 @@ if mswindows:
hStdError = None
wShowWindow = 0
else:
import select
_has_poll = hasattr(select, 'poll')
import _posixsubprocess
import select
import selectors
# When select or poll has indicated that the file is writable,
# we can write up to _PIPE_BUF bytes without risk of blocking.
# POSIX defines PIPE_BUF as >= 512.
_PIPE_BUF = getattr(select, 'PIPE_BUF', 512)
# poll/select have the advantage of not requiring any extra file
# descriptor, contrarily to epoll/kqueue (also, they require a single
# syscall).
if hasattr(selectors, 'PollSelector'):
_PopenSelector = selectors.PollSelector
else:
_PopenSelector = selectors.SelectSelector
__all__ = ["Popen", "PIPE", "STDOUT", "call", "check_call", "getstatusoutput",
"getoutput", "check_output", "CalledProcessError", "DEVNULL"]
......@@ -1530,12 +1538,65 @@ class Popen(object):
if not input:
self.stdin.close()
if _has_poll:
stdout, stderr = self._communicate_with_poll(input, endtime,
orig_timeout)
else:
stdout, stderr = self._communicate_with_select(input, endtime,
orig_timeout)
stdout = None
stderr = None
# Only create this mapping if we haven't already.
if not self._communication_started:
self._fileobj2output = {}
if self.stdout:
self._fileobj2output[self.stdout] = []
if self.stderr:
self._fileobj2output[self.stderr] = []
if self.stdout:
stdout = self._fileobj2output[self.stdout]
if self.stderr:
stderr = self._fileobj2output[self.stderr]
self._save_input(input)
with _PopenSelector() as selector:
if self.stdin and input:
selector.register(self.stdin, selectors.EVENT_WRITE)
if self.stdout:
selector.register(self.stdout, selectors.EVENT_READ)
if self.stderr:
selector.register(self.stderr, selectors.EVENT_READ)
while selector.get_map():
timeout = self._remaining_time(endtime)
if timeout is not None and timeout < 0:
raise TimeoutExpired(self.args, orig_timeout)
ready = selector.select(timeout)
self._check_timeout(endtime, orig_timeout)
# XXX Rewrite these to use non-blocking I/O on the file
# objects; they are no longer using C stdio!
for key, events in ready:
if key.fileobj is self.stdin:
chunk = self._input[self._input_offset :
self._input_offset + _PIPE_BUF]
try:
self._input_offset += os.write(key.fd, chunk)
except OSError as e:
if e.errno == errno.EPIPE:
selector.unregister(key.fileobj)
key.fileobj.close()
else:
raise
else:
if self._input_offset >= len(self._input):
selector.unregister(key.fileobj)
key.fileobj.close()
elif key.fileobj in (self.stdout, self.stderr):
data = os.read(key.fd, 4096)
if not data:
selector.unregister(key.fileobj)
key.fileobj.close()
self._fileobj2output[key.fileobj].append(data)
self.wait(timeout=self._remaining_time(endtime))
......@@ -1569,167 +1630,6 @@ class Popen(object):
self._input = self._input.encode(self.stdin.encoding)
def _communicate_with_poll(self, input, endtime, orig_timeout):
stdout = None # Return
stderr = None # Return
if not self._communication_started:
self._fd2file = {}
poller = select.poll()
def register_and_append(file_obj, eventmask):
poller.register(file_obj.fileno(), eventmask)
self._fd2file[file_obj.fileno()] = file_obj
def close_unregister_and_remove(fd):
poller.unregister(fd)
self._fd2file[fd].close()
self._fd2file.pop(fd)
if self.stdin and input:
register_and_append(self.stdin, select.POLLOUT)
# Only create this mapping if we haven't already.
if not self._communication_started:
self._fd2output = {}
if self.stdout:
self._fd2output[self.stdout.fileno()] = []
if self.stderr:
self._fd2output[self.stderr.fileno()] = []
select_POLLIN_POLLPRI = select.POLLIN | select.POLLPRI
if self.stdout:
register_and_append(self.stdout, select_POLLIN_POLLPRI)
stdout = self._fd2output[self.stdout.fileno()]
if self.stderr:
register_and_append(self.stderr, select_POLLIN_POLLPRI)
stderr = self._fd2output[self.stderr.fileno()]
self._save_input(input)
while self._fd2file:
timeout = self._remaining_time(endtime)
if timeout is not None and timeout < 0:
raise TimeoutExpired(self.args, orig_timeout)
try:
ready = poller.poll(timeout)
except OSError as e:
if e.args[0] == errno.EINTR:
continue
raise
self._check_timeout(endtime, orig_timeout)
# XXX Rewrite these to use non-blocking I/O on the
# file objects; they are no longer using C stdio!
for fd, mode in ready:
if mode & select.POLLOUT:
chunk = self._input[self._input_offset :
self._input_offset + _PIPE_BUF]
try:
self._input_offset += os.write(fd, chunk)
except OSError as e:
if e.errno == errno.EPIPE:
close_unregister_and_remove(fd)
else:
raise
else:
if self._input_offset >= len(self._input):
close_unregister_and_remove(fd)
elif mode & select_POLLIN_POLLPRI:
data = os.read(fd, 4096)
if not data:
close_unregister_and_remove(fd)
self._fd2output[fd].append(data)
else:
# Ignore hang up or errors.
close_unregister_and_remove(fd)
return (stdout, stderr)
def _communicate_with_select(self, input, endtime, orig_timeout):
if not self._communication_started:
self._read_set = []
self._write_set = []
if self.stdin and input:
self._write_set.append(self.stdin)
if self.stdout:
self._read_set.append(self.stdout)
if self.stderr:
self._read_set.append(self.stderr)
self._save_input(input)
stdout = None # Return
stderr = None # Return
if self.stdout:
if not self._communication_started:
self._stdout_buff = []
stdout = self._stdout_buff
if self.stderr:
if not self._communication_started:
self._stderr_buff = []
stderr = self._stderr_buff
while self._read_set or self._write_set:
timeout = self._remaining_time(endtime)
if timeout is not None and timeout < 0:
raise TimeoutExpired(self.args, orig_timeout)
try:
(rlist, wlist, xlist) = \
select.select(self._read_set, self._write_set, [],
timeout)
except OSError as e:
if e.args[0] == errno.EINTR:
continue
raise
# According to the docs, returning three empty lists indicates
# that the timeout expired.
if not (rlist or wlist or xlist):
raise TimeoutExpired(self.args, orig_timeout)
# We also check what time it is ourselves for good measure.
self._check_timeout(endtime, orig_timeout)
# XXX Rewrite these to use non-blocking I/O on the
# file objects; they are no longer using C stdio!
if self.stdin in wlist:
chunk = self._input[self._input_offset :
self._input_offset + _PIPE_BUF]
try:
bytes_written = os.write(self.stdin.fileno(), chunk)
except OSError as e:
if e.errno == errno.EPIPE:
self.stdin.close()
self._write_set.remove(self.stdin)
else:
raise
else:
self._input_offset += bytes_written
if self._input_offset >= len(self._input):
self.stdin.close()
self._write_set.remove(self.stdin)
if self.stdout in rlist:
data = os.read(self.stdout.fileno(), 1024)
if not data:
self.stdout.close()
self._read_set.remove(self.stdout)
stdout.append(data)
if self.stderr in rlist:
data = os.read(self.stderr.fileno(), 1024)
if not data:
self.stderr.close()
self._read_set.remove(self.stderr)
stderr.append(data)
return (stdout, stderr)
def send_signal(self, sig):
"""Send a signal to the process
"""
......
Lib/test/test_subprocess.py
View file @ 3a4586a9
......@@ -11,6 +11,7 @@ import errno
import tempfile
import time
import re
import selectors
import sysconfig
import warnings
import select
......@@ -2179,15 +2180,16 @@ class CommandTests(unittest.TestCase):
os.rmdir(dir)
@unittest.skipUnless(getattr(subprocess, '_has_poll', False),
"poll system call not supported")
@unittest.skipUnless(hasattr(selectors, 'PollSelector'),
"Test needs selectors.PollSelector")
class ProcessTestCaseNoPoll(ProcessTestCase):
def setUp(self):
subprocess._has_poll = False
self.orig_selector = subprocess._PopenSelector
subprocess._PopenSelector = selectors.SelectSelector
ProcessTestCase.setUp(self)
def tearDown(self):
subprocess._has_poll = True
subprocess._PopenSelector = self.orig_selector
ProcessTestCase.tearDown(self)
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7