多进程多线程GDB调试

  多进程多线程GDB调试

一、线程调试指南：

1. gdb attach pid 挂载到调试进程 

2. gdb$ set scheduler-locking on 只执行当前选定线程的开关

3. gdb$ info threads 显示当前进程中的线程

==============out put example=========================

 12 Thread 0x41f16940 (LWP 6922)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  11 Thread 0x42917940 (LWP 6923)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  10 Thread 0x43318940 (LWP 6924)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  9 Thread 0x43d19940 (LWP 6925)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  8 Thread 0x4471a940 (LWP 6926)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  7 Thread 0x4511b940 (LWP 6927)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  6 Thread 0x40a03940 (LWP 6928)  0x00000036e7c0ab99 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0

  5 Thread 0x40b04940 (LWP 6929)  0x00000036e7c0ab99 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0

  4 Thread 0x40c05940 (LWP 6930)  0x00000036e7c0ab99 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0

  3 Thread 0x4521c940 (LWP 6931)  0x00000036e7c0ab99 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0

  2 Thread 0x45c1d940 (LWP 6932)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  1 Thread 0x2b277c3bba40 (LWP 6913)  0x00000036e74cced2 in select () from /lib64/libc.so.6

==============out put example=========================

  说明 进程中的线程安装 1,2,3 ..编号

4. gdb$ thread 1  调试1线程

   gdb$ info threads

==============out put example=========================

 12 Thread 0x41f16940 (LWP 6922)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  11 Thread 0x42917940 (LWP 6923)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  10 Thread 0x43318940 (LWP 6924)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  9 Thread 0x43d19940 (LWP 6925)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  8 Thread 0x4471a940 (LWP 6926)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  7 Thread 0x4511b940 (LWP 6927)  0x00000036e74cced2 in select () from /lib64/libc.so.6

  6 Thread 0x40a03940 (LWP 6928)  0x00000036e7c0ab99 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0

  5 Thread 0x40b04940 (LWP 6929)  0x00000036e7c0ab99 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0

  4 Thread 0x40c05940 (LWP 6930)  0x00000036e7c0ab99 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0

  3 Thread 0x4521c940 (LWP 6931)  0x00000036e7c0ab99 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0

  2 Thread 0x45c1d940 (LWP 6932)  0x00000036e74cced2 in select () from /lib64/libc.so.6

 *1 Thread 0x2b277c3bba40 (LWP 6913)  0x00000036e74cced2 in select () from /lib64/libc.so.6

==============out put example=========================   

  *代表选定线程

  

5. gdb$ b function_name 设置断点端到的函数

6. 通过执行

   gdb$ thread id  调试id线程

   执行

   gdb$ continue

   如果能够到达断点说明，函数在该函数中执行，运气很好，直接开始调试

   

   否则，CTRL+C 跳出该线程

   

   调试下一个线程，直到找到调试线程，开始调试。

   

二、进程调试指南：

程序又多个进程组成，在一个父进程中创建子进程，调试方法如下：

gdb$ set follow-fork-mode [child|parent] 设置fork后，跟踪进程

后续可以再进行多线程调试。

  

以上功能是在gdb6.4的功能

gdb6.6中增加了

gdb$ set detach-on-fork [on|off]

   on: 断开 follow-fork-mode 指定进程

   off:gdb控制调试父子进程，follow-fork-mode指定进程被调试，另外一个被挂起。