https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63614
Bug ID: 63614
Summary: With gcc-4.8.3 and -stdgnu++0x call to
std::this_thread::get_id() creates SIGSEV
Product: gcc
Version: 4.8.3
Status: UNCONFIRMED
Severity: critical
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: dyle at dyle dot org
Things have worked recently until I run into a SIGSEV rigtht in the guts of
std::this_thread::id(). I tried several compiler options but still the program
crashes.
The whole compiler line within a cmake projekt for my sources causing the crash
read:
...
[ 56%] Building CXX object
bin/modules/qkd-hardware-pickup/CMakeFiles/qkd-hardware-pickup.dir/qkd-hardware-pickup-alice.cpp.o
cd /home/dyle/doc/src/ait/qkd/build/bin/modules/qkd-hardware-pickup &&
/usr/bin/c++ -DQT_CORE_LIB -DQT_DBUS_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB
-DQT_NO_DEBUG -DQT_XML_LIB -DVERSION=\"9.9999.2\" -D_BSD_SOURCE -D_GNU_SOURCE
-std=gnu++0x -Werror -Wall -Wextra -pedantic -g -ggdb3 -rdynamic -O3
-I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -isystem /usr/include/qt4
-isystem /usr/include/qt4/QtGui -isystem /usr/include/qt4/QtDBus -isystem
/usr/include/qt4/QtXml -isystem /usr/include/qt4/QtNetwork -isystem
/usr/include/qt4/QtCore -I/usr/include/qwt6 -I/home/dyle/doc/src/ait/qkd/build
-I/home/dyle/doc/src/ait/qkd -I/home/dyle/doc/src/ait/qkd/include
-I/home/dyle/doc/src/ait/qkd/build/bin/modules/qkd-hardware-pickup -o
CMakeFiles/qkd-hardware-pickup.dir/qkd-hardware-pickup-alice.cpp.o -c
/home/dyle/doc/src/ait/qkd/bin/modules/qkd-hardware-pickup/qkd-hardware-pickup-alice.cpp
/usr/bin/cmake -E cmake_progress_report
/home/dyle/doc/src/ait/qkd/build/CMakeFiles
...
This is then gdb:
GNU gdb (Gentoo 7.8 vanilla) 7.8
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-pc-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://bugs.gentoo.org/>.
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For help, type "help".
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Reading symbols from
bin/modules/qkd-hardware-pickup/qkd-hardware-pickup...done.
warning: core file may not match specified executable file.
[New LWP 27565]
[New LWP 27561]
[New LWP 27564]
[New LWP 27562]
[New LWP 27554]
[New LWP 27560]
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `/home/dyle/doc/src/ait/qkd/build/bin/qkd-hardware-pickup
--debug-core-presiftin'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 __gthread_self () at
/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.3/include/g++-v4/x86_64-pc-linux-gnu/bits/gthr-default.h:686
686 return __gthrw_(pthread_self) ();
(gdb) bt
#0 __gthread_self () at
/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.3/include/g++-v4/x86_64-pc-linux-gnu/bits/gthr-default.h:686
#1 get_id () at
/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.3/include/g++-v4/thread:252
#2 qkd_hardware_pickup_alice::presifter (this=0x1f1fbc0) at
/home/dyle/doc/src/ait/qkd/bin/modules/qkd-hardware-pickup/qkd-hardware-pickup-alice.cpp:1195
#3 0x00007f9f31cdd5e0 in std::(anonymous
namespace)::execute_native_thread_routine (__p=<optimized out>) at
/var/tmp/portage/sys-devel/gcc-4.8.3/work/gcc-4.8.3/libstdc++-v3/src/c++11/thread.cc:84
#4 0x00007f9f31f38073 in start_thread (arg=0x7f9f26193700) at
pthread_create.c:309
#5 0x00007f9f314624ad in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:111
(gdb) list
/home/dyle/doc/src/ait/qkd/bin/modules/qkd-hardware-pickup/qkd-hardware-pickup-alice.cpp:1195
1190 *
1191 * here the presift calculation starts
1192 */
1193 void qkd_hardware_pickup_alice::presifter() {
1194
1195 std::thread::id nThreadId = std::this_thread::get_id();
1196
1197 // this method is run at start by PRESIFT_THREADS concurrent
threads
1198 if (debug_core_presifting()) {
1199 qkd::utility::debug(true) <<
The thread itself is created at line 622, here:
(gdb) list
/home/dyle/doc/src/ait/qkd/bin/modules/qkd-hardware-pickup/qkd-hardware-pickup-alice.cpp:622
617
618 set_role((unsigned long)qkd::module::module_role::ROLE_ALICE);
619
620 // launch worker threads
621 d->cPusher = std::thread([this]{ pusher(); });
622 for (int i = 0; i < PRESIFT_THREADS; ++i) d->cPresifter[i] =
std::thread([this]{ presifter(); });
623
624 // wind down worker threads when termination signal emitted
625 connect(this, SIGNAL(terminated()), SLOT(stop_worker_threads()));
626 }
This is compiled with -stdgnu++0x.
Is this a gcc bug? Is it possible that std::this_thread::get_id() SIGSEVs?
Maybe it is due to my way of creating threads via lambda expression like this
in class A constructor:
$ cat t.cpp
#include <iostream>
#include <thread>
class A {
public:
std::thread t;
A() {
t = std::thread([this]{ foo(); });
}
private:
void foo() {
std::this_thread::sleep_for(std::chrono::seconds(1));
std::cout << "A::foo() - " << std::this_thread::get_id() << std::endl;
}
};
int main() {
A a;
std::this_thread::sleep_for(std::chrono::seconds(1));
std::cout << "main() - " << std::this_thread::get_id() << std::endl;
a.t.join();
return 0;
}
$ g++ -std=gnu++0x -pthread t.cpp
$ ./a.out
main() - 140454910891840
A::foo() - 140454894458624
(Yes, there's a race condition on std::cout. But this is not the point.) Is
there a drawback by creating a threads that way and could there be any
correlation to my sigsev?
An then: -pthread is missing in the crashing program. But it crashes with it as
well.
Is there any remedy? Or is this not a gcc bug at all?
