首先一个简单程序源代码：
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <omp.h>
4 int main(int argc, char * argv[]){
5 int i, k,m,n;
6 printf("i=%d,threads_num=%d\n",i, omp_get_num_threads());
7 printf("i=%d,thread_id=%d\n",i, omp_get_thread_num());
8 #pragma omp parallel for
9 for(i=0;i<4;i++)
10 {
11 k=10;
12 m=10;
13 n=k+m;
14 printf("i=%d,n=%d,thread_id=%d\n",i,n, omp_get_thread_num());
15 if(k>1)
16 printf("OK\n");
17 }
18 return 1;
19 }
编译成 test_omp
step 1：gdb test_omp
step 2：break 15
step 3：run
(gdb) r Starting program: /home/xqc/gmptest/test_omp [Thread debugging using libthread_db enabled] i=0,threads_num=1 i=0,thread_id=0 [New Thread 0x7ffff740f700 (LWP 17108)] [New Thread 0x7ffff6c0e700 (LWP 17109)] [New Thread 0x7ffff640d700 (LWP 17110)] Breakpoint 1, main.omp_fn.0 (.omp_data_i=0x7fffffffe3b0) at test_omp.c:15 15 k=10; (gdb)
(gdb) info threads 4 Thread 0x7ffff640d700 (LWP 17110) main.omp_fn.0 (.omp_data_i=0x7fffffffe3b0) at test_omp.c:15 3 Thread 0x7ffff6c0e700 (LWP 17109) main.omp_fn.0 (.omp_data_i=0x7fffffffe3b0) at test_omp.c:15 2 Thread 0x7ffff740f700 (LWP 17108) main.omp_fn.0 (.omp_data_i=0x7fffffffe3b0) at test_omp.c:15 * 1 Thread 0x7ffff7fdf780 (LWP 17105) main.omp_fn.0 (.omp_data_i=0x7fffffffe3b0) at test_omp.c:15 (gdb)
step4： thread 2
(gdb) thread 2
[Switching to thread 2 (Thread 0x7ffff740f700 (LWP 17108))]#0 main.omp_fn.0 (.omp_data_i=0x7fffffffe3b0)
at test_omp.c:15
15 k=10;
(gdb)
至此，就可以对thread 2号线程进行debug了。