diff --git a/Lib/socketserver.py b/Lib/socketserver.py index cd367f15e2d..c8a8db1950e 100644 --- a/Lib/socketserver.py +++ b/Lib/socketserver.py @@ -133,6 +133,7 @@ import socket import select import sys import os +import errno try: import threading except ImportError: @@ -147,6 +148,15 @@ if hasattr(socket, "AF_UNIX"): "ThreadingUnixStreamServer", "ThreadingUnixDatagramServer"]) +def _eintr_retry(func, *args): + """restart a system call interrupted by EINTR""" + while True: + try: + return func(*args) + except OSError as e: + if e.errno != errno.EINTR: + raise + class BaseServer: """Base class for server classes. @@ -222,7 +232,8 @@ class BaseServer: # connecting to the socket to wake this up instead of # polling. Polling reduces our responsiveness to a # shutdown request and wastes cpu at all other times. - r, w, e = select.select([self], [], [], poll_interval) + r, w, e = _eintr_retry(select.select, [self], [], [], + poll_interval) if self in r: self._handle_request_noblock() finally: @@ -262,7 +273,7 @@ class BaseServer: timeout = self.timeout elif self.timeout is not None: timeout = min(timeout, self.timeout) - fd_sets = select.select([self], [], [], timeout) + fd_sets = _eintr_retry(select.select, [self], [], [], timeout) if not fd_sets[0]: self.handle_timeout() return diff --git a/Lib/test/test_socketserver.py b/Lib/test/test_socketserver.py index b3660c1e6cf..0e76c33d1bf 100644 --- a/Lib/test/test_socketserver.py +++ b/Lib/test/test_socketserver.py @@ -8,6 +8,8 @@ import os import select import signal import socket +import select +import errno import tempfile import unittest import socketserver @@ -226,6 +228,38 @@ class SocketServerTest(unittest.TestCase): socketserver.DatagramRequestHandler, self.dgram_examine) + @contextlib.contextmanager + def mocked_select_module(self): + """Mocks the select.select() call to raise EINTR for first call""" + old_select = select.select + + class MockSelect: + def __init__(self): + self.called = 0 + + def __call__(self, *args): + self.called += 1 + if self.called == 1: + # raise the exception on first call + raise OSError(errno.EINTR, os.strerror(errno.EINTR)) + else: + # Return real select value for consecutive calls + return old_select(*args) + + select.select = MockSelect() + try: + yield select.select + finally: + select.select = old_select + + def test_InterruptServerSelectCall(self): + with self.mocked_select_module() as mock_select: + pid = self.run_server(socketserver.TCPServer, + socketserver.StreamRequestHandler, + self.stream_examine) + # Make sure select was called again: + self.assertGreater(mock_select.called, 1) + # Alas, on Linux (at least) recvfrom() doesn't return a meaningful # client address so this cannot work: diff --git a/Misc/ACKS b/Misc/ACKS index 77cec5c645e..3693c1c5750 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -510,6 +510,7 @@ Damon Kohler Marko Kohtala Vlad Korolev Joseph Koshy +Jerzy Kozera Maksim Kozyarchuk Stefan Krah Bob Kras diff --git a/Misc/NEWS b/Misc/NEWS index 4af242a0b48..924c7dcb930 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -39,6 +39,10 @@ Core and Builtins Library ------- +- Issue #7978: socketserver now restarts the select() call when EINTR is + returned. This avoids crashing the server loop when a signal is received. + Patch by Jerzy Kozera. + - Issue #14496: Fix wrong name in idlelib/tabbedpages.py. Patch by Popa Claudiu.