Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Hi, It is a well known bug to be checking the errno value without first checking that the system call failed. The errno number has no meaning _unless_ the system call failed, it doesn't matter what it's value is if there hasn't been an error. Hope that helps... Ed -- | Ed Griffiths, Acedb/ZMap development, Computational Genomics Group,| | The Sulston Building, Sanger Institute, Wellcome Trust Genome Campus, | | Hinxton, Cambridge CB10 1HH | || | email: edg...@sanger.ac.uk Tel: +44-1223-496844 Fax: +44-1223-494919 | -- The Wellcome Trust Sanger Institute is operated by Genome Research Limited, a charity registered in England with number 1021457 and a company registered in England with number 2742969, whose registered office is 215 Euston Road, London, NW1 2BE. Hello, Am 21.01.2015 22:31, schrieb KIU Shueng Chuan: Are you sure that the ioctl call failed? You are printing out errno wit hout having checked the return code of the ioctl call. -Snipp- that actually was the problem!!! My own code had more debug checks to verify that none of the previous calls failed. But that debug code never checked the contents of errno before the end! zmq_bind() may return successfully (zmq_bind() == 0), but it still leaves errno non-equal to zero. And in my real program I didn't use the return code of the ioctl call but the errno value. Thank you for helping me find this! Now the question: is it proper behaviour of zmq_bind() to change errno to a non-success value and then return successfully? Or should ZMQ everywhere that it works around temporary errors reset errno to zero on success? Best regards, Olaf Mandel -- Olaf Mandel phone: +49-89-189166-250 fax: +49-89-189166-111 Menlo Systems GmbH Am Klopferspitz 19a, D-82152 Martinsried Amtsgericht München HRB 138145 Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth USt-IdNr. DE217772017, St.-Nr. 14316170324 signature.asc Description: OpenPGP digital signature ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Hello, Am 21.01.2015 22:31, schrieb KIU Shueng Chuan: Are you sure that the ioctl call failed? You are printing out errno without having checked the return code of the ioctl call. -Snipp- that actually was the problem!!! My own code had more debug checks to verify that none of the previous calls failed. But that debug code never checked the contents of errno before the end! zmq_bind() may return successfully (zmq_bind() == 0), but it still leaves errno non-equal to zero. And in my real program I didn't use the return code of the ioctl call but the errno value. Thank you for helping me find this! Now the question: is it proper behaviour of zmq_bind() to change errno to a non-success value and then return successfully? Or should ZMQ everywhere that it works around temporary errors reset errno to zero on success? Best regards, Olaf Mandel -- Olaf Mandel phone: +49-89-189166-250 fax: +49-89-189166-111 Menlo Systems GmbH Am Klopferspitz 19a, D-82152 Martinsried Amtsgericht München HRB 138145 Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth USt-IdNr. DE217772017, St.-Nr. 14316170324 signature.asc Description: OpenPGP digital signature ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Hello, Am 20.01.2015 22:02, schrieb Arnaud Kapp: -Snipp- On Tue, Jan 20, 2015 at 11:32 AM, Olaf Mandel o.man...@menlosystems.com wrote: -Snipp- Good point, my machine and version numbers are: CPU: Freescale i.MX537 (Cortex-A8, NEON) GCC: 4.8.1, cross-compiling Linux: 3.10.28 + many platform patches ZMQ: zeromq/libzmq.git @ be23e699c -Snipp- I see two things to try: * Try with a more stable version of libzmq - https://github.com/zeromq/zeromq4-1 * Upgrading to a more recent kernel and to gcc 4.9 if those are available. this took a while, but I have now recompiled the complete system (including kernel) with GCC 4.9.2. I will not be able to go for a newer kernel: that has quite a few patches and porting those is a somewhat daunting task for me. The behaviour seems the same with the following combinations of ZeroMQ and GCC: ZeroMQ w/ GCC: 4.0.5 w/ 4.8.1 HEAD w/ 4.8.1 HEAD w/ 4.9.2 4.1.0 w/ 4.9.2 I want to check a bit why C and C++ behave differently tomorrow. Any further suggestions anyone could make? Best regards, Olaf Mandel -- Olaf Mandel phone: +49-89-189166-250 fax: +49-89-189166-111 Menlo Systems GmbH Am Klopferspitz 19a, D-82152 Martinsried Amtsgericht München HRB 138145 Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth USt-IdNr. DE217772017, St.-Nr. 14316170324 signature.asc Description: OpenPGP digital signature ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Are you sure that the ioctl call failed? You are printing out errno without having checked the return code of the ioctl call. Hello, Am 20.01.2015 22:02, schrieb Arnaud Kapp: -Snipp- On Tue, Jan 20, 2015 at 11:32 AM, Olaf Mandel o.man...@menlosystems.com wrote: -Snipp- Good point, my machine and version numbers are: CPU: Freescale i.MX537 (Cortex-A8, NEON) GCC: 4.8.1, cross-compiling Linux: 3.10.28 + many platform patches ZMQ: zeromq/libzmq.git @ be23e699c -Snipp- I see two things to try: * Try with a more stable version of libzmq - https://github.com/zeromq/zeromq4-1 * Upgrading to a more recent kernel and to gcc 4.9 if those are available. this took a while, but I have now recompiled the complete system (including kernel) with GCC 4.9.2. I will not be able to go for a newer kernel: that has quite a few patches and porting those is a somewhat daunting task for me. The behaviour seems the same with the following combinations of ZeroMQ and GCC: ZeroMQ w/ GCC: 4.0.5 w/ 4.8.1 HEAD w/ 4.8.1 HEAD w/ 4.9.2 4.1.0 w/ 4.9.2 I want to check a bit why C and C++ behave differently tomorrow. Any further suggestions anyone could make? Best regards, Olaf Mandel -- Olaf Mandel phone: +49-89-189166-250 fax: +49-89-189166-111 Menlo Systems GmbH Am Klopferspitz 19a, D-82152 Martinsried Amtsgericht München HRB 138145 Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth USt-IdNr. DE217772017, St.-Nr. 14316170324 ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
[zeromq-dev] ZMQ vs SPI: FD shenanigans
Hello,
I was trying to use ZMQ in a C++ program that also uses the STL to open
regular files and that uses the open(2) and ioctl(2) syscalls of the
Linux kernel for SPI communication (on an ARM platform). For certain
combinations of opening and closing a regular file and binding to a TCP
or Inproc socket, a subsequent ioctl call fails with either No such
device or Resource temporarily unavailable.
My first guess is that somehow ZMQ is messing up the file descriptors it
uses, but I am certainly not ready to rule out bugs in the STL, Kernel
or (least probably): my own code :-)
Could anyone give me a suggestion on how continue debugging this?
This is my demo code of the problem. The code uses the C++ binding for
ZMQ (cppzmq) for brevity, but it should work the same for the native C
interface.
#include sys/ioctl.h
#include zmq.hpp
//#define ADDR tcp://127.0.0.1:8000
#define ADDR inproc://addr
/*
* The program works fine if D is present and it shows the problem if
* D is commented out for the following permutations of the blocks:
* - A B C D
* - A C B D
* - C A B D
*
* The program always shows the problem (independent of the presence
* of D) for the following permutations of the blocks:
* - A C D B
* - C A D B
* - C D A B
*
* With the constraint that A must be before B and C before D, there
* are no further valid permutations.
*
* For the TCP address, the error message is: No such device
* For the inproc address, it is: Resource temporarily unavailable
*/
int main()
{
zmq::context_t ctx;/* A */
zmq::socket_t skt(ctx, ZMQ_PUB); /* B */
skt.bind(ADDR);
std::fstream fs(log, std::ios::out); /* C */
fs.close();/* D */
/* The following always last */
int fd = open(/dev/spidev32766.0, O_RDWR);
struct spi_ioc_transfer pcks;
memset(pcks, 0, sizeof(struct spi_ioc_transfer));
ioctl(fd, SPI_IOC_MESSAGE(1), pcks);
std::cout errno: strerror(errno) std::endl;
return 0;
}
Thank you for any suggestion,
Olaf Mandel
--
Olaf Mandel
phone: +49-89-189166-250
fax: +49-89-189166-111
Menlo Systems GmbH
Am Klopferspitz 19a, D-82152 Martinsried
Amtsgericht München HRB 138145
Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth
USt-IdNr. DE217772017, St.-Nr. 14316170324
signature.asc
Description: OpenPGP digital signature
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Hello Thomas,
thank you for the quick answer.
Am 20.01.2015 15:11, schrieb Thomas Rodgers:
Do you see the same behavior if you replace C with fopen() ?
-Snipp-
Not quite: if the error occurs, the behaviour is the same as before. But
now the error _always_ happens: closing the file descriptor in the C
version of the test makes no difference. New test below:
/*
* Compile with:
* g++ -Wall -Werror -Wextra -pedantic -x c -o test test.c -lzmq
*/
#include fcntl.h
#include linux/spi/spidev.h
#include stdio.h
#include string.h
#include sys/ioctl.h
#include zmq.h
/*#define ADDR tcp://127.0.0.1:8000*/
#define ADDR inproc://addr
/*
* The program always shows the problem (independent of the presence
* of D) for the following permutations of the blocks:
* - A B C D
* - A C B D
* - A C D B
* - C A B D
* - C A D B
* - C D A B
*
* With the constraint that A must be before B and C before D, there
* are no further valid permutations.
*
* For the TCP address, the error message is: No such device
* For the inproc address, it is: Resource temporarily unavailable
*/
int main()
{
void* ctx;
void* skt;
FILE* f;
intfd;
struct spi_ioc_transfer pcks;
ctx = zmq_ctx_new();/* A */
skt = zmq_socket(ctx, ZMQ_PUB); /* B */
zmq_bind(skt, ADDR);
f = fopen(log, w); /* C */
(void)sizeof(f);
fclose(f); /* D */
/* The following always last */
fd = open(/dev/spidev32766.0, O_RDWR);
memset(pcks, 0, sizeof(struct spi_ioc_transfer));
ioctl(fd, SPI_IOC_MESSAGE(1), pcks);
printf(errno: %s\n, strerror(errno));
return 0;
}
The one advantage of this is: I now at least can see the FILE structure
and the contained _fileno member.
Any further thoughts?
Olaf Mandel
--
Olaf Mandel
phone: +49-89-189166-250
fax: +49-89-189166-111
Menlo Systems GmbH
Am Klopferspitz 19a, D-82152 Martinsried
Amtsgericht München HRB 138145
Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth
USt-IdNr. DE217772017, St.-Nr. 14316170324
signature.asc
Description: OpenPGP digital signature
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Do you see the same behavior if you replace C with fopen() ? On Tue, Jan 20, 2015 at 7:40 AM, Olaf Mandel o.man...@menlosystems.com wrote: Am 20.01.2015 14:35, schrieb Olaf Mandel: -Snipp- #include sys/ioctl.h #include zmq.hpp -Snipp- Shoot: That was missing a few include statements at the top the program and the compile instructions. Correct start of the demo program: /* * Compile with: * g++ -Wall -Werror -Wextra -o test test.cpp -lzmq */ #include fcntl.h #include fstream #include iostream #include linux/spi/spidev.h #include sys/ioctl.h #include zmq.hpp Sorry about that, Olaf Mandel -- Olaf Mandel phone: +49-89-189166-250 fax: +49-89-189166-111 Menlo Systems GmbH Am Klopferspitz 19a, D-82152 Martinsried Amtsgericht München HRB 138145 Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth USt-IdNr. DE217772017, St.-Nr. 14316170324 ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Am 20.01.2015 14:35, schrieb Olaf Mandel: -Snipp- #include sys/ioctl.h #include zmq.hpp -Snipp- Shoot: That was missing a few include statements at the top the program and the compile instructions. Correct start of the demo program: /* * Compile with: * g++ -Wall -Werror -Wextra -o test test.cpp -lzmq */ #include fcntl.h #include fstream #include iostream #include linux/spi/spidev.h #include sys/ioctl.h #include zmq.hpp Sorry about that, Olaf Mandel -- Olaf Mandel phone: +49-89-189166-250 fax: +49-89-189166-111 Menlo Systems GmbH Am Klopferspitz 19a, D-82152 Martinsried Amtsgericht München HRB 138145 Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth USt-IdNr. DE217772017, St.-Nr. 14316170324 signature.asc Description: OpenPGP digital signature ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Hello,
I don't really see anything in the small example that could cause a bug.
I am myself using libzmq (with zmqpp as a wrapper) on a Raspberry Pi +
a Piface digital card (which is a SPI device), and I have no trouble.
My kernel version is 3.12.28+ and I use a recent (a few commits behind
HEAD) version of libzmq.
On Tue, Jan 20, 2015 at 4:28 PM, Thomas Rodgers rodg...@twrodgers.com wrote:
No, not really. libc++ doesn't do anything particularly interesting with
fd's but I just wanted to formally rule it out.
Unfortunately I don't have a system (or any experience dealing) with SPI
devices. I don't think libzmq does anything particularly 'funky' with any of
the file descriptors it manages though (at least based on my reading of the
source).
On Tue, Jan 20, 2015 at 8:56 AM, Olaf Mandel o.man...@menlosystems.com
wrote:
Hello Thomas,
thank you for the quick answer.
Am 20.01.2015 15:11, schrieb Thomas Rodgers:
Do you see the same behavior if you replace C with fopen() ?
-Snipp-
Not quite: if the error occurs, the behaviour is the same as before. But
now the error _always_ happens: closing the file descriptor in the C
version of the test makes no difference. New test below:
/*
* Compile with:
* g++ -Wall -Werror -Wextra -pedantic -x c -o test test.c -lzmq
*/
#include fcntl.h
#include linux/spi/spidev.h
#include stdio.h
#include string.h
#include sys/ioctl.h
#include zmq.h
/*#define ADDR tcp://127.0.0.1:8000*/
#define ADDR inproc://addr
/*
* The program always shows the problem (independent of the presence
* of D) for the following permutations of the blocks:
* - A B C D
* - A C B D
* - A C D B
* - C A B D
* - C A D B
* - C D A B
*
* With the constraint that A must be before B and C before D, there
* are no further valid permutations.
*
* For the TCP address, the error message is: No such device
* For the inproc address, it is: Resource temporarily unavailable
*/
int main()
{
void* ctx;
void* skt;
FILE* f;
intfd;
struct spi_ioc_transfer pcks;
ctx = zmq_ctx_new();/* A */
skt = zmq_socket(ctx, ZMQ_PUB); /* B */
zmq_bind(skt, ADDR);
f = fopen(log, w); /* C */
(void)sizeof(f);
fclose(f); /* D */
/* The following always last */
fd = open(/dev/spidev32766.0, O_RDWR);
memset(pcks, 0, sizeof(struct spi_ioc_transfer));
ioctl(fd, SPI_IOC_MESSAGE(1), pcks);
printf(errno: %s\n, strerror(errno));
return 0;
}
The one advantage of this is: I now at least can see the FILE structure
and the contained _fileno member.
Any further thoughts?
Olaf Mandel
--
Olaf Mandel
phone: +49-89-189166-250
fax: +49-89-189166-111
Menlo Systems GmbH
Am Klopferspitz 19a, D-82152 Martinsried
Amtsgericht München HRB 138145
Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth
USt-IdNr. DE217772017, St.-Nr. 14316170324
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
--
Kapp Arnaud - Xaqq
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Hello, Am 20.01.2015 18:07, schrieb Arnaud Kapp: I don't really see anything in the small example that could cause a bug. I am myself using libzmq (with zmqpp as a wrapper) on a Raspberry Pi + a Piface digital card (which is a SPI device), and I have no trouble. At least in the C++ version, the problem is relatively fragile: it only occurs if mixing ZMQ socket operations binds/connects with opening and closing files. There are cases where I also don't see the problem. Weirdly, I always see the problem in my pure-C test... My kernel version is 3.12.28+ and I use a recent (a few commits behind HEAD) version of libzmq. -Snipp- Good point, my machine and version numbers are: CPU: Freescale i.MX537 (Cortex-A8, NEON) GCC: 4.8.1, cross-compiling Linux: 3.10.28 + many platform patches ZMQ: zeromq/libzmq.git @ be23e699c Any other info of interest? Best regards, Olaf Mandel -- Olaf Mandel phone: +49-89-189166-250 fax: +49-89-189166-111 Menlo Systems GmbH Am Klopferspitz 19a, D-82152 Martinsried Amtsgericht München HRB 138145 Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth USt-IdNr. DE217772017, St.-Nr. 14316170324 signature.asc Description: OpenPGP digital signature ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
No, not really. libc++ doesn't do anything particularly interesting with
fd's but I just wanted to formally rule it out.
Unfortunately I don't have a system (or any experience dealing) with SPI
devices. I don't think libzmq does anything particularly 'funky' with any
of the file descriptors it manages though (at least based on my reading of
the source).
On Tue, Jan 20, 2015 at 8:56 AM, Olaf Mandel o.man...@menlosystems.com
wrote:
Hello Thomas,
thank you for the quick answer.
Am 20.01.2015 15:11, schrieb Thomas Rodgers:
Do you see the same behavior if you replace C with fopen() ?
-Snipp-
Not quite: if the error occurs, the behaviour is the same as before. But
now the error _always_ happens: closing the file descriptor in the C
version of the test makes no difference. New test below:
/*
* Compile with:
* g++ -Wall -Werror -Wextra -pedantic -x c -o test test.c -lzmq
*/
#include fcntl.h
#include linux/spi/spidev.h
#include stdio.h
#include string.h
#include sys/ioctl.h
#include zmq.h
/*#define ADDR tcp://127.0.0.1:8000*/
#define ADDR inproc://addr
/*
* The program always shows the problem (independent of the presence
* of D) for the following permutations of the blocks:
* - A B C D
* - A C B D
* - A C D B
* - C A B D
* - C A D B
* - C D A B
*
* With the constraint that A must be before B and C before D, there
* are no further valid permutations.
*
* For the TCP address, the error message is: No such device
* For the inproc address, it is: Resource temporarily unavailable
*/
int main()
{
void* ctx;
void* skt;
FILE* f;
intfd;
struct spi_ioc_transfer pcks;
ctx = zmq_ctx_new();/* A */
skt = zmq_socket(ctx, ZMQ_PUB); /* B */
zmq_bind(skt, ADDR);
f = fopen(log, w); /* C */
(void)sizeof(f);
fclose(f); /* D */
/* The following always last */
fd = open(/dev/spidev32766.0, O_RDWR);
memset(pcks, 0, sizeof(struct spi_ioc_transfer));
ioctl(fd, SPI_IOC_MESSAGE(1), pcks);
printf(errno: %s\n, strerror(errno));
return 0;
}
The one advantage of this is: I now at least can see the FILE structure
and the contained _fileno member.
Any further thoughts?
Olaf Mandel
--
Olaf Mandel
phone: +49-89-189166-250
fax: +49-89-189166-111
Menlo Systems GmbH
Am Klopferspitz 19a, D-82152 Martinsried
Amtsgericht München HRB 138145
Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth
USt-IdNr. DE217772017, St.-Nr. 14316170324
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
At least in the C++ version, the problem is relatively fragile I always see the problem in my pure-C test There are those that maintain that C is a simpler and more robust language than C++ :-)~ On Tue, Jan 20, 2015 at 11:32 AM, Olaf Mandel o.man...@menlosystems.com wrote: Hello, Am 20.01.2015 18:07, schrieb Arnaud Kapp: I don't really see anything in the small example that could cause a bug. I am myself using libzmq (with zmqpp as a wrapper) on a Raspberry Pi + a Piface digital card (which is a SPI device), and I have no trouble. At least in the C++ version, the problem is relatively fragile: it only occurs if mixing ZMQ socket operations binds/connects with opening and closing files. There are cases where I also don't see the problem. Weirdly, I always see the problem in my pure-C test... My kernel version is 3.12.28+ and I use a recent (a few commits behind HEAD) version of libzmq. -Snipp- Good point, my machine and version numbers are: CPU: Freescale i.MX537 (Cortex-A8, NEON) GCC: 4.8.1, cross-compiling Linux: 3.10.28 + many platform patches ZMQ: zeromq/libzmq.git @ be23e699c Any other info of interest? Best regards, Olaf Mandel -- Olaf Mandel phone: +49-89-189166-250 fax: +49-89-189166-111 Menlo Systems GmbH Am Klopferspitz 19a, D-82152 Martinsried Amtsgericht München HRB 138145 Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth USt-IdNr. DE217772017, St.-Nr. 14316170324 ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] ZMQ vs SPI: FD shenanigans
Haha be careful Thomas or you will wake Pieter :) Well I am mixing socket operations binds/connects with opening and closing files (and reading and writing from/to files). I also use ZMQ to poll on my files' descriptors. So at first sight it doesn't look like a ZMQ bug. I see two things to try: * Try with a more stable version of libzmq - https://github.com/zeromq/zeromq4-1 * Upgrading to a more recent kernel and to gcc 4.9 if those are available. Good luck ! On Tue, Jan 20, 2015 at 6:45 PM, Thomas Rodgers rodg...@twrodgers.com wrote: At least in the C++ version, the problem is relatively fragile I always see the problem in my pure-C test There are those that maintain that C is a simpler and more robust language than C++ :-)~ On Tue, Jan 20, 2015 at 11:32 AM, Olaf Mandel o.man...@menlosystems.com wrote: Hello, Am 20.01.2015 18:07, schrieb Arnaud Kapp: I don't really see anything in the small example that could cause a bug. I am myself using libzmq (with zmqpp as a wrapper) on a Raspberry Pi + a Piface digital card (which is a SPI device), and I have no trouble. At least in the C++ version, the problem is relatively fragile: it only occurs if mixing ZMQ socket operations binds/connects with opening and closing files. There are cases where I also don't see the problem. Weirdly, I always see the problem in my pure-C test... My kernel version is 3.12.28+ and I use a recent (a few commits behind HEAD) version of libzmq. -Snipp- Good point, my machine and version numbers are: CPU: Freescale i.MX537 (Cortex-A8, NEON) GCC: 4.8.1, cross-compiling Linux: 3.10.28 + many platform patches ZMQ: zeromq/libzmq.git @ be23e699c Any other info of interest? Best regards, Olaf Mandel -- Olaf Mandel phone: +49-89-189166-250 fax: +49-89-189166-111 Menlo Systems GmbH Am Klopferspitz 19a, D-82152 Martinsried Amtsgericht München HRB 138145 Geschäftsführung: Dr Michael Mei, Dr Ronald Holzwarth USt-IdNr. DE217772017, St.-Nr. 14316170324 ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev -- Kapp Arnaud - Xaqq ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
