关于使用gdb的一些建议

参考：《Linux® Debugging and Performance Tuning: Tips and Techniques》 chapter 3

1. 测试程序

/home/a/j/nomad2:cat gdb_sample2.c 
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
void* Thread_function1(void * arg)
{
        unsigned int i=1;
        while(i < 11)
        {
                printf("Child Thread Iteration %d\n",i);
                i++;
                if(i%2)
                        sleep(2);
                else
                        sleep(1);
        }
        return arg;
}
void* Thread_function2(void * arg)
{
        unsigned int i=1;
        while(i < 11)
        {
                printf("Child Thread 2 Iteration %d\n",i);
                i++;
                if(i%2)
                        sleep(2);
                else
                        sleep(1);
        }
        return arg;
}
int main (int argc, char *argv[])
{
        pthread_t thread;
        pthread_t thread2;
        if(pthread_create(&thread,NULL,Thread_function1,NULL))
        {
                return(1);
        }
        if(pthread_create(&thread2,NULL,Thread_function2,NULL))
        {
                return(1);
        }
        unsigned int i = 1;
        while(i < 11)
        {
                printf("Main Loop Iteration %d\n",i);
                i++;
                if(i%2)
                        sleep(1);
                else
                        sleep(2);
        }
        return 0;
}

3.  关于调试：
1). When debugging, it is often a good practice to stop program execution at the bottom of a function so that a print or multiple displays can be done to see the current values stored in the data the function has altered. 
list       <func name>
break  <line of }>

2). When gdb is used, the print command must

be invoked to display the variable's value. The user can see much more information at one time.