作者:爱你116564 | 来源:互联网 | 2023-02-04 10:19
以下代码有什么问题?运行时,程序以未知异常中止
#include
#include
int main() {
auto promise = std::promise{};
auto future_One= promise.get_future();
promise.set_value(1);
return 0;
}
错误输出是
terminate called after throwing an instance of 'std::system_error'
what(): Unknown error -1
Aborted (core dumped)
g++ --version
对我来说
g++ (Ubuntu 5.4.0-6ubuntu1~16.04.2) 5.4.0 20160609
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
相同的代码在mac上运行得很好
注意异常源自的代码行是promise.set_value(1)
1> Mine..:
简而言之,添加-pthread
可以解决您的问题.
$ g++ -std=c++14 -g -pthread -o temp temp.cpp
$ ./temp
细节
我可以在编译时使用以下命令重现Ubuntu 16.04上的行为:
$ g++ -std=c++14 -g -o temp temp.cpp
$ ./temp
terminate called after throwing an instance of 'std::system_error'
what(): Unknown error -1
Aborted (core dumped)
GDB转储显示:
(gdb) bt
#0 0x00007ffff74ab428 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
#1 0x00007ffff74ad02a in __GI_abort () at abort.c:89
#2 0x00007ffff7ae484d in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#3 0x00007ffff7ae26b6 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4 0x00007ffff7ae2701 in std::terminate() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#5 0x00007ffff7ae2919 in __cxa_throw () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#6 0x00007ffff7b0b7fe in std::__throw_system_error(int) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#7 0x000000000040259b in std::call_once ()>*, bool*), std::__future_base::_State_baseV2*, std::function ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function ()>*&&, bool*&&) (__Once=...,
__f=) at /usr/include/c++/5/mutex:746
#8 0x0000000000401e06 in std::__future_base::_State_baseV2::_M_set_result(std::function ()>, bool) (this=0x61ac30, __res=..., __ignore_failure=false) at /usr/include/c++/5/future:387
#9 0x0000000000402aee in std::promise::set_value(int&&) (this=0x7fffffffe1c0, __r=) at /usr/include/c++/5/future:1075
#10 0x0000000000401759 in main () at temp.cpp:7
从转储中,我们可以看到它正在使用互斥锁等.然后我意识到这些std::future
东西依赖于线程,所以它需要链接pthread
,否则我们会看到这个异常.
同样的 std::thread