[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Kristján Valur Jónsson added the comment: fixed for 2.7 -- resolution: - fixed status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Roundup Robot added the comment: New changeset 8ec39bfd1f01 by Kristján Valur Jónsson in branch '2.7': Issue #9090 : Error code 10035 calling socket.recv() on a socket with a timeout http://hg.python.org/cpython/rev/8ec39bfd1f01 -- nosy: +python-dev ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Roundup Robot added the comment: New changeset f22b93b318a5 by Kristján Valur Jónsson in branch '2.7': issue #9090 : Limit the fix to windows since getting a portable simple http://hg.python.org/cpython/rev/f22b93b318a5 -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Roundup Robot added the comment: New changeset 0f5e1e642dc3 by Kristján Valur Jónsson in branch '2.7': issue #9090 : Take the same approach for socketmodule as daytimemodule http://hg.python.org/cpython/rev/0f5e1e642dc3 -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Kristján Valur Jónsson added the comment: Here is a patch for 2.7 Since 2.7 doesn't have pytime.c, we export floattime() as _Py_floattime out of time.c -- Added file: http://bugs.python.org/file29453/socket.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Kristján Valur Jónsson added the comment: I will backport this. I have recently seen this happening in 2.7 in our company and it would make sense to fix this before 2.7.4 is released. -- nosy: +kristjan.jonsson ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Jesús Cea Avión added the comment: Backport to 2.7 should be done: See Issue #16274. -- nosy: +jcea ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Okko Willeboordse okko.willeboor...@gmail.com added the comment: I bumped into this issue at one of my customers that use Python to control a machine through Beckhoff EtherCAT. The Python code communicates with the Beckhoff EtherCAT program using TCP/IP. They use non blocking sockets like so; s = select.select([self._socket], [], [], timeout)[0] if not s: raise NoData self._socket.recv(length) They also found that the recv occasionally raises a 10035. I changed the code in to; s = select.select([self._socket], [], [], timeout)[0] if not s: raise NoData try: buffer_ = self._socket.recv(length) except socket.error as inst: if (gaius.utils.Platform.WINDOWS and 10035 == inst.args[0]) or \ (gaius.utils.Platform.LINUX and 11 == inst.args[0]): raise NoData So this issue applies also to sockets without timeout, albeit it can be worked around easily. Also note that this also applies to Linux as the man page of select states in the BUG section; Under Linux, select() may report a socket file descriptor as ready for reading, while nevertheless a subsequent read blocks. This could for example happen when data has arrived but upon examination has wrong checksum and is discarded. There may be other circumstances in which a file descriptor is spuriously reported as ready. Thus it may be safer to use O_NONBLOCK on sockets that should not block. Note that Linux select is not Posix compliant as Posix states; A descriptor shall be considered ready for reading when a call to an input function with O_NONBLOCK clear would not block, whether or not the function would transfer data successfully. See https://lkml.org/lkml/2011/6/18/76 MSDN select says; For other sockets, readability means that queued data is available for reading such that a call to recv, WSARecv, WSARecvFrom, or recvfrom is guaranteed not to block. http://support.microsoft.com/kb/177346 says (for Windows 95); The Winsock select() API might fail to block on a nonblocking socket and return WSAEWOULDBLOCK as an error code when either send() or recv() is subsequently called. For example, select() may return indicating there is data to read, yet a call to recv() returns with the error code WSAEWOULDBLOCK, indicating there is no data immediately available. Windows NT 4.0 does not exhibit this behavior. Finally I have 2 questions; Is this select behavior on Windows 'normal'? Noting that it is not documented. or does it behaves this way due to crippled NIC's or drivers (VMWare)? Can this behavior be reproduced? I need this for automatic testing. Now these exceptional paths cannot be tested. -- nosy: +Okko.Willeboordse ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Changes by Terry J. Reedy tjre...@udel.edu: -- nosy: -terry.reedy ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Björn Lindqvist bjou...@gmail.com added the comment: I don't have the expertise to backport it myself, but the problem certainly is still present in python 2.7.1 on Windows 7. It is especially pronounced when using threading to read from multiple url files. -- nosy: +bjourne ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Antoine Pitrou pit...@free.fr added the comment: I will not bother backporting myself but an other core developer can do it if (s)he desires. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Terry J. Reedy tjre...@udel.edu added the comment: 2.6 is closed except for security fixes, which this does not seem to be. If the problem is in 2.7, then it potentially could be fixed there, but with the same caveats. I will let Antoine reclose if he thinks appropriate. -- nosy: +terry.reedy stage: committed/rejected - patch review versions: +Python 2.7 -Python 2.6 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Eric Hohenstein ehohenst...@imvu.com added the comment: I have ported the changes related to this problem from the 3.2 branch to the 2.6 version of socketmodule.c. The changes are attached as a diff from Python 2.6.2. The changes apply to all platforms but I've only tested them on Windows. The _PyTime_gettimeofday method is not available in 2.6 which is why the changes in 3.2 weren't originally back ported. I admit to adding a disgusting hack which was to copy some of the _PyTime_gettimeofday interface code from 3.2 to the socketmodule.c file and implement it using the time.time() method, falling back to the crt time() method. It's not as efficient as the implementation in 3.2 but I believe it should be equally correct. The motivation for doing this was that I continued to see 10035 errors happening using Python 2.6 though in different code paths. Specifically, errors were being thrown when uploading a file using a PUT request using httplib which calls sendall(). It's noteworthy that analysing the changes made for this issue to Python 3.2 revealed that no change was made to the sendall() method. sendall() is actually problematic in that the timeout on the socket may actually be exceeded without error if any one call to select() doesn't exceed the socket's timeout but in aggregate the calls to select do wait longer than the timeout. The same generic solution that was applied to the other socket methods is not appropriate for sendall(). I elected to continue this behavior by just checking for EAGAIN and EWOULDBLOCK if the socket has a positive timeout value and the call to send failed and continuing the select/send loop in that case. As far as I can tell, sendall() will still fail with these r ecoverable errors in Python 3.2. I won't feel bad if this patch is rejected for 2.6 but the changes to sendall() should really be considered for the 3.2 branch. -- resolution: fixed - status: closed - open versions: +Python 2.6 -Python 3.2 Added file: http://bugs.python.org/file20142/socket_10035.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Changes by Antoine Pitrou pit...@free.fr: -- status: pending - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Antoine Pitrou pit...@free.fr added the comment: Here is an updated patch wrapping all variants of recv() and send(), except sendall() which already has its own retry loop. -- Added file: http://bugs.python.org/file19046/selectretry2.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Antoine Pitrou pit...@free.fr added the comment: Committed in 3.2 in r85074. I don't plan to backport it, since the _PyTime_gettimeofday abstraction is not available on earlier versions. -- resolution: - fixed stage: patch review - committed/rejected status: open - pending versions: -Python 2.7, Python 3.1 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Charles-Francois Natali neolo...@free.fr added the comment: Unfortunately, select doesn't necessarily update the timeout variable with the remaining time, so we can't rely on this. This would mean having the select enclosed within gettimeofday and friends, which seems a bit overkill... -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Jean-Paul Calderone inva...@example.invalid added the comment: Unfortunately, select doesn't necessarily update the timeout variable with the remaining time, so we can't rely on this. This would mean having the select enclosed within gettimeofday and friends, which seems a bit overkill... How is it overkill to be correct? -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Antoine Pitrou pit...@free.fr added the comment: Unfortunately, select doesn't necessarily update the timeout variable with the remaining time, so we can't rely on this. This would mean having the select enclosed within gettimeofday and friends, which seems a bit overkill... Well, given the general cost of Python function calls and bytecode interpretation, it would probably not be much of a runtime overhead. So it's mainly some additional, not very exciting code to write :-) (luckily, in 3.2 we have a cross-platform gettimeofday() abstraction in pytime.h which will ease things quite a bit) -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Charles-Francois Natali neolo...@free.fr added the comment: Yes, I was concerned with the runtime overhead (especially under VMs, where clocks are emulated) and strace output ;-) As for the dull code writting, I could give it a shot unless someone else wants to go ahead. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Charles-Francois Natali neolo...@free.fr added the comment: @ehohenstein: sorry, I hadn't seen you'd already submitted a patch, so you may as well update it to take into account what was said above. Also, please note that this issue is not specific to windows, so it would be nice to fix it for Unices too. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Antoine Pitrou pit...@free.fr added the comment: Here is a proof of concept patch for Python 3.2. It only wraps recv() and recv_into(). recvfrom() and recvfrom_into() should receive the same treatment, at least. -- stage: - patch review Added file: http://bugs.python.org/file18925/selectretry.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Changes by Antoine Pitrou pit...@free.fr: -- nosy: +gregory.p.smith ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Changes by Antoine Pitrou pit...@free.fr: Removed file: http://bugs.python.org/file18925/selectretry.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Changes by Antoine Pitrou pit...@free.fr: Added file: http://bugs.python.org/file18926/selectretry.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Charles-Francois Natali neolo...@free.fr added the comment: Actually, it's possible that select(2) incorrectly reports sockets as ready for reading : for example if the socket receives data, but then discards it because of an invalid checksum (and I guess you're more likely to get this type of problem on a VM or while copying large files). -- nosy: +neologix ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Antoine Pitrou pit...@free.fr added the comment: So it means we should indeed retry on a socket with timeout... But we must take care not to exceed the original timeout, so we must measure the time taken by each select() call. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Ben Smith benjamin.coder.sm...@gmail.com added the comment: I also see this issue on occasion on windows XP SP 3, using python 2.6.5 to fetch large files via http. The error is infrequent, but it is happening in my situation without a VM. -- nosy: +Ben.Smith ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
Changes by Antoine Pitrou pit...@free.fr: -- nosy: +exarkun, giampaolo.rodola versions: +Python 2.7, Python 3.1, Python 3.2 -Python 2.6 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9090 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9090] Error code 10035 calling socket.recv() on a socket with a timeout (WSAEWOULDBLOCK - A non-blocking socket operation could not be completed immediately)
New submission from Eric Hohenstein ehohenst...@imvu.com:
This error is unfortunately difficult to reproduce. I've only seen it happen on
Windows XP running on a dual core VMWare VM. I haven't been able to reproduce
it on a non-VM system running Windows 7. The only way I've been able to
reproduce it is to run the following unit test repeatedly on the XP VM
repeatedly until it fails:
import unittest
import urllib2
class DownloadUrlTest(unittest.TestCase):
def testDownloadUrl(self):
opener = urllib2.build_opener()
handle = opener.open('http://localhost/', timeout=60)
handle.info()
data = handle.read()
self.assertNotEqual(data, '')
if __name__ == __main__:
unittest.main()
This unit test obviously depends on a web server running on localhost. In the
test environment where I was able to reproduce this problem the web server is
Win32 Apache 2.0.54 with mod_php. When the test fails, it fails with Windows
error code 10035 (WSAEWOULDBLOCK) being generated by the call to the recv()
method rougly once every 50-100 times the test is run. The following is a the
final entry in the stack when the error occurs:
File c:\slave\h05b15\build\Ext\Python26\lib\socket.py, line 353, in read
(self=socket._fileobject ...03B78170, size=1027091)
data = self._sock.recv(left)
The thing to note is that the socket is being created with a timeout of 60. The
implementation of the socket.recv() method in socketmodule.c in the _socket
import module is to use select() to wait for a socket to become readable for
socket objects with a timeout and then to call recv() on the socket only if
select() did not return indicating that the timeout period elapsed without the
socket becoming readable. The fact that Windows error code 10035
(WSAEWOULDBLOCK) is being generated in the sock_recv_guts() method in
socketmodule.c indicates that select() returned without timing out which means
that Windows must have indicated that the socket is readable when in fact it
wasn't. It appears that there is a known issue with Windows sockets where this
type of problem may occur with non-blocking sockets. It is described in the
msdn documentation for WSAAsyncSelect()
(http://msdn.microsoft.com/en-us/library/ms741540%28VS.85%29.aspx). The code
for socketmodule.c doesn't seem to hand
le this type of situation correctly. The patch I've included with this issue
report retries the select() if the recv() call fails with WSAWOULDBLOCK (only
if MS_WINDOWS is defined). With the patch in place the test ran approximately
23000 times without failure on the system where it was failing without the
patch.
--
components: IO, Windows
files: sock_recv.patch
keywords: patch
messages: 108770
nosy: ehohenstein
priority: normal
severity: normal
status: open
title: Error code 10035 calling socket.recv() on a socket with a timeout
(WSAEWOULDBLOCK - A non-blocking socket operation could not be completed
immediately)
type: behavior
versions: Python 2.6
Added file: http://bugs.python.org/file17780/sock_recv.patch
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