On 31/08/11 10:10, Arash Partow wrote:

g++ -Wall -pedantic -o timer5 timer5.cpp -lpthread -lboost_thread -lboost_system It compiles like a charm but when I execute I obtain the same Segmentation fault.

-- Alessandro Candini MEEO S.r.l. Via Saragat 9 I-44122 Ferrara, Italy Tel: +39 0532 1861501 Fax: +39 0532 1861637 http://www.meeo.it ======================================== "ATTENZIONE:le informazioni contenute in questo messaggio sono da considerarsi confidenziali ed il loro utilizzo è riservato unicamente al destinatario sopra indicato. Chi dovesse ricevere questo messaggio per errore è tenuto ad informare il mittente ed a rimuoverlo definitivamente da ogni supporto elettronico o cartaceo." "WARNING:This message contains confidential and/or proprietary information which may be subject to privilege or immunity and which is intended for use of its addressee only. Should you receive this message in error, you are kindly requested to inform the sender and to definitively remove it from any paper or electronic format."

On 31/08/11 21:10, Anthony Foiani wrote:

Alessandro, greetings --

Alessandro Candini writes:

...

I'm really interested in exemple 5 of boost asio:

http://www.boost.org/doc/libs/1_47_0/doc/html/boost_asio/tutorial/tuttimer5/...

I've tried it with boost-1.47.0. I can compile without warnings using:

g++ -Wall -pedantic -lboost_thread -lboost_system -o timer5 timer5.cpp

but when I launch the executable it gives me a Segmentation fault.

Commenting the code I found that the segmentation fault raise at the 3rd line of main:

boost::thread t(boost::bind(&boost::asio::io_service::run,&io));

I'm trying on the following machine: Linux office-007 2.6.38-11-generic #48-Ubuntu SMP Fri Jul 29 19:02:55 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux Not exactly the same setup, but on a very current gcc+boost on a similar system, it seems to work fine:

$ uname -a Linux foo 2.6.35.14-95.fc14.x86_64 #1 SMP \ Tue Aug 16 21:01:58 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

$ g++ -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/local/gcc-4.6.1/libexec/gcc/x86_64-unknown-linux-gnu/4.6.1/lto-wrapper Target: x86_64-unknown-linux-gnu Configured with: ../gcc-4.6.1/configure --prefix=/usr/local/gcc-4.6.1 \ --with-local-prefix=/usr/local/gcc-4.6.1/local \ --enable-languages=c,c++ --enable-threads Thread model: posix gcc version 4.6.1 (GCC)

$ g++ -Wall -pedantic -I/usr/local/boost/include \ -o boost-asio-segv boost-asio-segv.cpp \ -L /usr/local/boost/lib -lboost_thread -lboost_system

$ export LD_LIBRARY_PATH=/usr/local/gcc/lib64:/usr/local/boost/lib

$ ./boost-asio-segv Timer 1: 0 Timer 2: 1 Timer 1: 2 Timer 2: 3 Timer 1: 4 Timer 2: 5 Timer 1: 6 Timer 2: 7 Timer 1: 8 Timer 2: 9 Final count is 10

$ ldd ./boost-asio-segv linux-vdso.so.1 => (0x00007fffefda7000) libboost_thread.so.1.47.0 => /usr/local/boost/lib/libboost_thread.so.1.47.0 (0x00007f7898f96000) libboost_system.so.1.47.0 => /usr/local/boost/lib/libboost_system.so.1.47.0 (0x00007f7898d92000) libstdc++.so.6 => /usr/local/gcc/lib64/libstdc++.so.6 (0x00007f7898a8e000) libm.so.6 => /lib64/libm.so.6 (0x0000003da1a00000) libgcc_s.so.1 => /usr/local/gcc/lib64/libgcc_s.so.1 (0x00007f789885a000) libc.so.6 => /lib64/libc.so.6 (0x0000003da1200000) libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003da1600000) librt.so.1 => /lib64/librt.so.1 (0x0000003da2200000) /lib64/ld-linux-x86-64.so.2 (0x0000003da0e00000)

You might want to try using 'ldd' to make sure that it's pulling in a consistent set of libraries (no 32/64 mismatch, no boost version mismatch, etc).

Finally, use 'gdb' to see what is in "io" just before the segv. Just looking at that line, I don't see how either of those addresses could be null, which would be the usual cause of a segv. Maybe something like:

void * run_addr = static_cast< void *>(&boost::asio::io_service_run ); void * io_addr = static_cast< void *>(&io );

And see if either of those are null?

If you have the resources, can you try building your own g++ and boost, to see if it works under that combination?

If you still can't solve it, can you make sure to post the version of g++ that you're using?

...

"WARNING:This message contains confidential and/or proprietary information which may be subject to privilege or immunity and which is intended for use of its addressee only. Should you receive this message in error, you are kindly requested to inform the sender and to definitively remove it from any paper or electronic format." And this sort of thing is pretty useless / rude on a public mailing list, don't you think?

Best regards, Tony

p.s. I could also get the exact same source code to run under the "stock" install on up-to-date Fedora 14, which means g++ 4.5.1 and boost 1.44.0:

$ unset LD_LIBRARY_PATH

$ g++ -Wall -pedantic -o boost-asio-segv boost-asio-segv.cpp \ -lboost_thread-mt -lboost_system-mt

$ ./boost-asio-segv Timer 1: 0 Timer 2: 1 Timer 1: 2 Timer 2: 3 Timer 1: 4 Timer 2: 5 Timer 1: 6 Timer 2: 7 Timer 1: 8 Timer 2: 9 Final count is 10

$ rpm -q gcc boost-thread gcc-4.5.1-4.fc14.x86_64 boost-thread-1.44.0-8.fc14.x86_64 I have gcc-4.5.2 instead of 4.6.1, but this is not the problem. Now it works: the problem was indeed a link to old boost-1.42, not yet removed from my system.

Here's my steps to get it work: $ make g++ -Wall -pedantic -I/usr/local/include/boost -L /usr/local/lib -lboost_thread -lboost_system -o timer5 timer5.cpp $ ldd timer5 linux-vdso.so.1 => (0x00007ffff634e000) libboost_thread.so.1.47.0 => /usr/local/lib/libboost_thread.so.1.47.0 (0x00007fe590190000) libboost_system.so.1.47.0 => /usr/local/lib/libboost_system.so.1.47.0 (0x00007fe58ff8c000) libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fe58fc85000) libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fe58fa00000) libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fe58f7ea000) libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fe58f455000) libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fe58f237000) librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fe58f02f000) /lib64/ld-linux-x86-64.so.2 (0x00007fe5903dd000) $ ./timer5 Timer 1: 0 Timer 2: 1 Timer 1: 2 Timer 2: 3 Timer 1: 4 Timer 2: 5 Timer 1: 6 Timer 2: 7 Timer 1: 8 Timer 2: 9 Final count is 10 Thank you so much! -- Alessandro Candini MEEO S.r.l. Via Saragat 9 I-44122 Ferrara, Italy Tel: +39 0532 1861501 Fax: +39 0532 1861637 http://www.meeo.it ======================================== "ATTENZIONE:le informazioni contenute in questo messaggio sono da considerarsi confidenziali ed il loro utilizzo è riservato unicamente al destinatario sopra indicato. Chi dovesse ricevere questo messaggio per errore è tenuto ad informare il mittente ed a rimuoverlo definitivamente da ogni supporto elettronico o cartaceo." "WARNING:This message contains confidential and/or proprietary information which may be subject to privilege or immunity and which is intended for use of its addressee only. Should you receive this message in error, you are kindly requested to inform the sender and to definitively remove it from any paper or electronic format."