Question

所以，我有一个使用boost :: asio的应用程序。由于项目的复杂性，我无法分享它的源代码:(

该应用程序使用boost的asio lib来创建一些Web服务。然而，当试图使用它时，std :: type_info :: operator ==中有一个sigsegv，正如我所知，它应该更有效。

(gdb) backtrace
#0  0x0000000000457b79 in std::type_info::operator== (
this=0x7ffff6dadf61 <typeinfo for boost::asio::detail::typeid_wrapper<boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > >+1>, __arg=...)
at /usr/include/c++/4.8.2/typeinfo:123
#1  0x00007ffff6961911 in boost::asio::detail::service_registry::keys_match (key1=..., key2=...) at /usr/include/boost/asio/detail/impl/service_registry.ipp:94
#2  0x00007ffff69619a1 in boost::asio::detail::service_registry::do_use_service (this=0x6bd3c0, key=..., 
factory=0x7ffff6988ba8 <boost::asio::detail::service_registry::create<boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > >(boost::asio::io_service&)>)
at /usr/include/boost/asio/detail/impl/service_registry.ipp:114
#3  0x00007ffff69842b6 in boost::asio::detail::service_registry::use_service<boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > > (this=0x6bd3c0)
at /usr/include/boost/asio/detail/impl/service_registry.hpp:48

其余的回溯都是无效的，因为我认为它无论如何都会有所帮助。当进一步深入研究GDB打印的内容时，我得到的是：

(gdb) frame 0
#0  0x0000000000457b79 in std::type_info::operator== (
this=0x7ffff6dadf61 <typeinfo for boost::asio::detail::typeid_wrapper<boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > >+1>, __arg=...)
at /usr/include/c++/4.8.2/typeinfo:123
123                   || (__name[0] != '*' &&
(gdb) list
118             : __builtin_strcmp (__name, __arg.__name) < 0; }
119
120         bool operator==(const type_info& __arg) const _GLIBCXX_NOEXCEPT
121         {
122           return ((__name == __arg.__name)
123                   || (__name[0] != '*' &&
124                       __builtin_strcmp (__name, __arg.__name) == 0));
125         }
126       #else
127         // On some targets we can rely on type_info's NTBS being unique,
(gdb) print __name
$2 = 0xd000007ffff6afbc <Address 0xd000007ffff6afbc out of bounds>
(gdb) print __arg.__name
warning: can't find linker symbol for virtual table for `std::type_info' value
$3 = 0x7ffff6afbc60 <typeinfo name for boost::asio::detail::typeid_wrapper<boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > >> "N5boost4asio6detail14typeid_wrapperINS0_22deadline_timer_serviceINS_10posix_time5ptimeENS0_11time_traitsIS5_EEEEEE"
(gdb) print __name[0]
Cannot access memory at address 0xd000007ffff6afbc
(gdb) frame 1
#1  0x00007ffff6961911 in boost::asio::detail::service_registry::keys_match (key1=..., key2=...) at /usr/include/boost/asio/detail/impl/service_registry.ipp:94
94          if (*key1.type_info_ == *key2.type_info_)
(gdb) list
89      {
90        if (key1.id_ && key2.id_)
91          if (key1.id_ == key2.id_)
92            return true;
93        if (key1.type_info_ && key2.type_info_)
94          if (*key1.type_info_ == *key2.type_info_)
95            return true;
96        return false;
97      }
98
(gdb) print key1.type_info_
$4 = (const std::type_info *) 0x7ffff6dadf61 <typeinfo for boost::asio::detail::typeid_wrapper<boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > >+1>
(gdb) print *key1.type_info_
$5 = {_vptr.type_info = 0x6000000000006906, __name = 0xd000007ffff6afbc <Address 0xd000007ffff6afbc out of bounds>}
(gdb) print *key2.type_info_
warning: can't find linker symbol for virtual table for `std::type_info' value
$6 = warning: can't find linker symbol for virtual table for `std::type_info' value
{_vptr.type_info = 0x6906d0 <_ZTVN10__cxxabiv117__class_type_infoE@@CXXABI_1.3+16>, 
  __name = 0x7ffff6afbc60 <typeinfo name for boost::asio::detail::typeid_wrapper<boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > >> "N5boost4asio6detail14typeid_wrapperINS0_22deadline_timer_serviceINS_10posix_time5ptimeENS0_11time_traitsIS5_EEEEEE"}
(gdb) print key2.type_info_
$7 = (const std::type_info *) 0x7ffff6dadf60 <typeinfo for boost::asio::detail::typeid_wrapper<boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > >>

关于它为何如此工作的唯一理论是，应用程序由一个主二进制文件组成，它静态链接到必要的libboost * .a，它可以加载.so文件作为插件，每个都链接使用相同的libboost * .a。这是我现在能猜到的最好的。

任何人都知道为什么会失败，并且可以帮助我吗？

Answer 1

看起来服务没有通过typeid找到服务对象。

这意味着库的某些部分尚未进行兼容编译。

包括运行时所需的所有共享对象/库（并确保它们已加载，而不是系统）或根据目标系统上的库版本重新编译应用程序

（即使编译器标志中的差异可能导致某些平台中的ABI不兼容）

boost :: asio在std :: type_info :: operator ==中触发sigsegv

1 个答案: