I've just run my monthly port update and I decided that it was time to use 
std::thread/std::future to execute things in the background.

The problem is that in std::future is a call to std::call_once and that call 
crashes my code:

(gdb) where
#0  0x0000000000000000 in ?? ()
#1  0x00007fff8f7e0ff0 in pthread_once ()
#2  0x0000000102a29440 in __gthread_once (__once=0x115d186a0, 
__func=0x112951b10 <__once_proxy>) at gthr-default.h:718
#3  0x0000000102a3283d in 
_ZSt9call_onceIMNSt13__future_base11_State_baseEFvRSt8functionIFSt10unique_ptrINS0_12_Result_baseENS4_8_DeleterEEvEERbEIKPS1_St17reference_wrapperIS8_ESF_IbEEEvRSt9once_flagOT_DpOT0_
 (__once=@0x115d186a0, __f=@0x118146d10) at mutex:822
#4  0x0000000102a3118b in std::__future_base::_State_base::_M_set_result 
(this=0x115d18618, 
__res={<_Maybe_unary_or_binary_function<std::unique_ptr<std::__future_base::_Result_base,
 std::__future_base::_Result_base::_Deleter> >> = {<No data fields>}, 
<std::_Function_base> = {static _M_max_size = <optimized out>, static 
_M_max_align = <optimized out>, _M_functor = {_M_unused = {_M_object = 
0x114383670, _M_const_object = 0x114383670, _M_function_pointer = 0x114383670, 
_M_member_pointer = {__pfn = 0x114383670, __delta = 4631664872}}, _M_pod_data = 
"p68\024\001\000\000\000?\021\024\001\000\000"}, _M_manager = 0x102a3cfea 
<std::_Function_base::_Base_manager<std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<int>,
 std::__future_base::_Result_base::_Deleter>, int> 
>::_M_manager(std::_Any_data&, std::_Any_data const&, 
std::_Manager_operation)>}, _M_invoker = 0x102a3cf97 
<std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, 
std::__future_base::_Result_base::_Deleter> ()(), 
std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<int>,
 std::__future_base::_Result_base::_Deleter>, int> >::_M_invoke(std::_Any_data 
const&)>}, __ignore_failure=false) at future:359
#5  0x0000000102a38762 in std::__future_base::_Task_state<int ()()>::_M_run 
(this=0x115d18618) at future:1268
#6  0x0000000102a35548 in std::packaged_task<int ()()>::operator() 
(this=0x115d180d8) at future:1376

So I upgraded to gcc48 and noticed that the library libstdc++.dylib didn't 
change or update. In fact it linked to the same library being used by gcc47 in 
/opt/local/lib:
512_  ls -l /opt/local/lib/libstdc++.6.dylib
6344 -rwxr-xr-x  1 root  admin  3245696 Jul  1 10:14 
/opt/local/lib/libstdc++.6.dylib

Anyone else having problems with std::call_once?

Any workaround that can be suggested?

David

_______________________________________________
macports-users mailing list
macports-users@lists.macosforge.org
https://lists.macosforge.org/mailman/listinfo/macports-users

Reply via email to