[zeromq-dev] segfault in python during poll() (but it's my fault)

[Pieter Hintjens]

OK, great, I'll push that fix into the 3.2 stabilization branch as well.

-Pieter

On Thu, Nov 22, 2012 at 12:15 PM, Peter Friend <pfriend at gehrytech.com> wrote:
> That seems to have fixed it. With my old broken code the REQ socket never sees the message instead of dumping core, which I assume is the desired behavior. No exception is thrown.
>
> Thanks!
>
> Peter
>
> -----Original Message-----
> From: zeromq-dev-bounces at lists.zeromq.org [mailto:zeromq-dev-bounces at lists.zeromq.org] On Behalf Of Martin Hurton
> Sent: Wednesday, November 21, 2012 2:55 PM
> To: 0MQ development list
> Subject: Re: [zeromq-dev] segfault in python during poll() (but it's my fault)
>
> The master contains patch that should fix the crash. Can you please
> test and report back? Thanks! - Martin
>
> On Wed, Nov 21, 2012 at 9:33 PM, Martin Hurton <hurtonm at gmail.com> wrote:
>> Hi Peter, could you please create an issue for this and attach a
>> simple example, best in C,  to reproduce this segfault? Thanks!
>>
>> - Martin
>>
>> On Wed, Nov 21, 2012 at 4:49 PM, Martin Hurton <hurtonm at gmail.com> wrote:
>>> Thanks for report, I will check it.
>>>
>>> On Nov 20, 2012 3:18 AM, "Peter Friend" <pfriend at gehrytech.com> wrote:
>>>>
>>>> I have a client REQ talking to a ROUTER. I am translating some prototype
>>>> code from python to Java so the ROUTER is in Java and the REQ client is
>>>> python. I was rather perplexed when I got a segfault during poll():
>>>>
>>>>
>>>>
>>>> socks = dict(polldev.poll(10 * 1000))
>>>>
>>>>
>>>>
>>>> from strace:
>>>>
>>>> write(6, "\1\0\0\0\0\0\0\0", 8)         = 8
>>>>
>>>> write(8, "\1\0\0\0\0\0\0\0", 8)         = 8
>>>>
>>>> poll([{fd=8, events=POLLIN}], 1, 0)     = 1 ([{fd=8, revents=POLLIN}])
>>>>
>>>> read(8, "\1\0\0\0\0\0\0\0", 8)          = 8
>>>>
>>>> poll([{fd=8, events=POLLIN}], 1, 0)     = 0 (Timeout)
>>>>
>>>> write(6, "\1\0\0\0\0\0\0\0", 8)         = 8
>>>>
>>>> fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0
>>>>
>>>> mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
>>>> 0x7fc8abbed000
>>>>
>>>> write(1, "sending 1\n", 10sending 1
>>>>
>>>> )             = 10
>>>>
>>>> poll([{fd=8, events=POLLIN}], 1, 0)     = 1 ([{fd=8, revents=POLLIN}])
>>>>
>>>> poll([{fd=8, events=POLLIN}], 1, 0)     = 1 ([{fd=8, revents=POLLIN}])
>>>>
>>>> read(8, "\1\0\0\0\0\0\0\0", 8)          = 8
>>>>
>>>> poll([{fd=8, events=POLLIN}], 1, 0)     = 0 (Timeout)
>>>>
>>>> poll([{fd=8, events=POLLIN}], 1, 10000 <unfinished ...>
>>>>
>>>> +++ killed by SIGSEGV (core dumped) +++
>>>>
>>>>
>>>>
>>>> This ended up being caused by the fact that I forgot to put in the empty
>>>> frame for the reply to the REQ. Once I did that everything worked, but I
>>>> wouldn't expect this to cause a segfault. I am working on a Java REQ client
>>>> as well to verify whether it's a core library issue. I am using my own build
>>>> of libzmq from the master branch I built today.
>>>>
>>>>
>>>>
>>>> Thanks,
>>>>
>>>>
>>>>
>>>> Peter
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> zeromq-dev mailing list
>>>> zeromq-dev at lists.zeromq.org
>>>> http://lists.zeromq.org/mailman/listinfo/zeromq-dev
>>>>
>>>
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