linux进程线程管理实验报告(9)

进程线程,死锁实验报告

pthread_mutex_unlock(&mutex2);

pthread_mutex_unlock(&mutex1);

}

}

void critical_section(int thread_num,int i){

printf("Thread%d:%d\n",thread_num,i);

}

1. 你预想deadlock.c 的运行结果会如何？

2. deadlock.c 的实际运行结果如何？多次运行每次的现象都一样吗？为什么会这样？

四、实验结果

4.1 通过加锁可修改thread.c程序，使得main_counter与sum值同步，源代码如下：

#include<stdio.h>

#include<sys/types.h>

#include<unistd.h>

#include<ctype.h>

#include<pthread.h>

#define MAX_THREAD 3

unsigned long long main_counter,counter[MAX_THREAD];

void* thread_worker(void*);

int main(int argc,char argv[]){

int i,rtn;

char ch;

pthread_t pthread_id[MAX_THREAD]={0};

for(i=0;i<MAX_THREAD;i++){

pthread_create(&pthread_id[i],NULL,thread_worker,(void*)i);

}

do{

unsigned long long sum=0;

for(i=0;i<MAX_THREAD;i++){

sum+=counter[i];

printf("counter[%d]=%llu\n",i,counter[i]);

}

printf("main_counter=%llu/sum=%llu\n",main_counter,sum);

}while((ch=getchar())!='q');

return 0;

}