[Python-checkins] r78523 - in python/trunk: Lib/subprocess.py Lib/test/test_subprocess.py Misc/NEWS

Mon Mar 1 01:05:08 CET 2010

Author: gregory.p.smith
Date: Mon Mar 1 01:05:08 2010
New Revision: 78523
Log:
Issue #1068268: The subprocess module now handles EINTR in internal
os.waitpid and os.read system calls where appropriate.
Modified:
 python/trunk/Lib/subprocess.py
 python/trunk/Lib/test/test_subprocess.py
 python/trunk/Misc/NEWS
Modified: python/trunk/Lib/subprocess.py
==============================================================================

--- python/trunk/Lib/subprocess.py	(original)
+++ python/trunk/Lib/subprocess.py	Mon Mar 1 01:05:08 2010
@@ -476,6 +476,16 @@
 STDOUT = -2
 
 
+def _eintr_retry_call(func, *args):
+ while True:
+ try:
+ return func(*args)
+ except OSError, e:
+ if e.errno == errno.EINTR:
+ continue
+ raise
+
+
 def call(*popenargs, **kwargs):
 """Run command with arguments. Wait for command to complete, then
 return the returncode attribute.
@@ -1173,13 +1183,14 @@
 os.close(errwrite)
 
 # Wait for exec to fail or succeed; possibly raising exception
- data = os.read(errpipe_read, 1048576) # Exception limited to 1M
+ # Exception limited to 1M
+ data = _eintr_retry_call(os.read, errpipe_read, 1048576)
 finally:
 # be sure the FD is closed no matter what
 os.close(errpipe_read)
 
 if data != "":
- os.waitpid(self.pid, 0)
+ _eintr_retry_call(os.waitpid, self.pid, 0)
 child_exception = pickle.loads(data)
 for fd in (p2cwrite, c2pread, errread):
 if fd is not None:
@@ -1215,7 +1226,7 @@
 """Wait for child process to terminate. Returns returncode
 attribute."""
 if self.returncode is None:
- pid, sts = os.waitpid(self.pid, 0)
+ pid, sts = _eintr_retry_call(os.waitpid, self.pid, 0)
 self._handle_exitstatus(sts)
 return self.returncode
 
Modified: python/trunk/Lib/test/test_subprocess.py
==============================================================================
--- python/trunk/Lib/test/test_subprocess.py	(original)
+++ python/trunk/Lib/test/test_subprocess.py	Mon Mar 1 01:05:08 2010
@@ -4,6 +4,7 @@
 import sys
 import signal
 import os
+import errno
 import tempfile
 import time
 import re
@@ -772,11 +773,30 @@
 ProcessTestCase.tearDown(self)
 
 
+class HelperFunctionTests(unittest.TestCase):
+ def test_eintr_retry_call(self):
+ record_calls = []
+ def fake_os_func(*args):
+ record_calls.append(args)
+ if len(record_calls) == 2:
+ raise OSError(errno.EINTR, "fake interrupted system call")
+ return tuple(reversed(args))
+
+ self.assertEqual((999, 256),
+ subprocess._eintr_retry_call(fake_os_func, 256, 999))
+ self.assertEqual([(256, 999)], record_calls)
+ # This time there will be an EINTR so it will loop once.
+ self.assertEqual((666,),
+ subprocess._eintr_retry_call(fake_os_func, 666))
+ self.assertEqual([(256, 999), (666,), (666,)], record_calls)
+
+
 def test_main():
 unit_tests = (ProcessTestCase,
 POSIXProcessTestCase,
 Win32ProcessTestCase,
- ProcessTestCaseNoPoll)
+ ProcessTestCaseNoPoll,
+ HelperFunctionTests)
 
 test_support.run_unittest(*unit_tests)
 test_support.reap_children()
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS	(original)
+++ python/trunk/Misc/NEWS	Mon Mar 1 01:05:08 2010
@@ -75,6 +75,9 @@
 - Issue #7481: When a threading.Thread failed to start it would leave the
 instance stuck in initial state and present in threading.enumerate().
 
+- Issue #1068268: The subprocess module now handles EINTR in internal
+ os.waitpid and os.read system calls where appropriate.
+
 Extension Modules
 -----------------
 
