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我正在研究多线程应用程序，当进程转储它总是生成核心时，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 它是这样显示的

(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.
4

2 回答 2

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。

您似乎还试图调试优化的代码，构建时没有-g标记，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您的核心更新）。

确保您的可执行文件和GDB 输出中列出的所有库在 生成核心的系统和您正在分析核心的系统之间完全匹配（如果它们不相同）——这是最重要的——如果存在是不匹配的，您可能会得到虚假的堆栈跟踪（并且您发布的堆栈跟踪在我看来确实完全是虚假的）。info shared

于 2010-02-24T07:11:55.303 回答
1

在我看来，您在没有适当标志的多线程应用程序中使用 iostream。看到这个。特别是，请注意它说

当您构建使用 libC 库的 iostream 类在多线程环境中运行的应用程序时，请使用 -mt 选项编译和链接应用程序的源代码。此选项将 -D_REENTRANT 传递给预处理器，将 -lthread 传递给链接器。

这是针对特定平台的；您的要求可能会有所不同。

于 2010-02-22T16:25:16.710 回答