无法分析多线程应用程序的核心转储问题......（需要帮助）

Question

我正在开发多线程应用程序，每当进程转储时，它总是生成核心，如下所示，我无法理解它实际转储的位置。

GNU gdb Red Hat Linux (6.5-25.el5rh)
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This GDB was configured as "x86_64-redhat-linux-gnu"...(no debugging symbols found)
Using host libthread_db library "/lib64/libthread_db.so.1".


warning: exec file is newer than core file.
Core was generated by `multithreadprocess                                                                       '.
Program terminated with signal 11, Segmentation fault.
#0  0x0000000000448f7a in std::ostream::operator<< ()
(gdb) where
0x000000000044bd32 in std::ostream::operator<< ()
#1  0x0000000000450b21 in std::ostream::operator<< ()
#2  0x000000000042eda9 in std::string::operator= ()
#3  0x00000030582062e7 in start_thread () from /lib64/libpthread.so.0
#4  0x00000030576ce3bd in clone () from /lib64/libc.so.6

(gdb)thread apply all bt 
Thread 6 (process 11674):
#0  0x000000305820a687 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x0000000000431140 in std::string::operator= ()
#2  0x00000030582062e7 in start_thread () from /lib64/libpthread.so.0
#3  0x00000030576ce3bd in clone () from /lib64/libc.so.6

Thread 5 (process 11683):
#0  0x000000305820cbfb in write () from /lib64/libpthread.so.0
#1  0x0000000000449151 in std::ostream::operator<< ()
#2  0x000000000043b74a in std::string::operator= ()
#3  0x000000000046c3f4 in std::string::substr ()
#4  0x000000000046e3c1 in std::string::substr ()
#5  0x00000000004305a4 in std::string::operator= ()
#6  0x00000030582062e7 in start_thread () from /lib64/libpthread.so.0
#7  0x00000030576ce3bd in clone () from /lib64/libc.so.6

Thread 4 (process 11744):
#0  0x00000030576c5896 in poll () from /lib64/libc.so.6
#1  0x0000000000474f1c in std::string::substr ()
#2  0x000000000043b889 in std::string::operator= ()
#3  0x0000000000474dbc in std::string::substr ()
#4  0x00000000004306a5 in std::string::operator= ()
#5  0x00000030582062e7 in start_thread () from /lib64/libpthread.so.0
#6  0x00000030576ce3bd in clone () from /lib64/libc.so.6

Thread 3 (process 11864):
#0  0x000000305820a687 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x0000000000431140 in std::string::operator= ()
#2  0x00000030582062e7 in start_thread () from /lib64/libpthread.so.0
#3  0x00000030576ce3bd in clone () from /lib64/libc.so.6

Thread 2 (process 11866):
#0  0x000000305820a687 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x0000000000431140 in std::string::operator= ()
#2  0x00000030582062e7 in start_thread () from /lib64/libpthread.so.0
#3  0x00000030576ce3bd in clone () from /lib64/libc.so.6

Thread 1 (process 11865):
#0  0x000000000044bd32 in std::ostream::operator<< ()
#1  0x0000000000450b21 in std::ostream::operator<< ()
#2  0x000000000042eda9 in std::string::operator= ()
#3  0x00000030582062e7 in start_thread () from /lib64/libpthread.so.0
#4  0x00000030576ce3bd in clone () from /lib64/libc.so.6

如果我给 bt full 它显示像这样

(gdb) bt full
#0  0x000000000044bd32 in std::ostream::operator<< ()
No symbol table info available.
#1  0x0000000000450b21 in std::ostream::operator<< ()
No symbol table info available.
#2  0x000000000042eda9 in std::string::operator= ()
No symbol table info available.
#3  0x00000030582062e7 in start_thread () from /lib64/libpthread.so.0
No symbol table info available.
#4  0x00000030576ce3bd in clone () from /lib64/libc.so.6
No symbol table info available.

Answer 1

GDB 6.5 已经很老了。您可能会从（当前）GDB 7.0.1 获得明显更好的堆栈跟踪。

您似乎还尝试调试优化的代码，在没有 -g 标志的情况下构建，并且您可能没有调试正确的可执行文件（GDB 警告您的可执行文件比核心新）。

确保您的可执行文件和所有信息共享 GDB 输出中列出的库在您所在的系统之间完全匹配生成的核心和您正在分析核心的系统（如果它们不相同）——这是最重要的——如果不匹配，您可能会得到虚假的堆栈跟踪（并且您发布的堆栈跟踪对我来说确实看起来完全是假的）。

Answer 2

在我看来，您在多线程应用程序中使用 iostream 时没有适当的标志。请参见 此。特别要注意的是，它说

当您构建一个应用程序时
使用 libC 的 iostream 类
在多线程中运行的库
环境，编译并链接
应用程序的源代码使用
-mt 选项。该选项通过
-D_REENTRANT 用于预处理器，-lthread 用于链接器。

这是针对特定平台的；您的要求可能会有所不同。