读写锁训练 - qidao123.com技术社区-IT企服评测·应用市场

#include<stdio.h>
#include<time.h>
#include <unistd.h>
#include <pthread.h>
#include <string.h>
pthread_rwlock_t rwlock = PTHREAD_RWLOCK_INITIALIZER;
void *task_1(void *arg)
{
char buf[100] = {0};
while(1){
//获取读操作锁
pthread_rwlock_rdlock(&rwlock);
//以只读方式打开文件
FILE *fp = fopen("./a.txt","r");
fread(buf,1,100,fp);
char *str = strtok(buf,"|");
printf("%s\n",str);
//归还读操作锁
pthread_rwlock_unlock(&rwlock);
sleep(1);
}
}
void *task_2(void *arg)
{
char buf[100] = {0};
while(1){
//获取读操作锁
pthread_rwlock_rdlock(&rwlock);
//以只读方式打开文件
FILE *fp = fopen("./a.txt","r");
fread(buf,1,100,fp);
char *str = strtok(buf,"|");
str = strtok(NULL,"|");
printf("%s\n",str);
//归还读操作锁
pthread_rwlock_unlock(&rwlock);
sleep(1);
}
}
int main()
{
time_t tim;
struct tm *ptim;
int wday;
char buf[100] = {0};
pthread_t task1;
pthread_t task2;
//初始化读写锁
pthread_rwlock_init(&rwlock,NULL);
//创建两个线程
pthread_create(&task1,NULL,task_1,NULL);
pthread_create(&task2,NULL,task_2,NULL);
while(1){
//获取当前系统时间
tim = time(NULL);
//转换为年月日时分秒
ptim = localtime(&tim);
//将转换好的日期放入buf
sprintf(buf,"%d 年 %d 月 %d 日 | %d ：%d : %d\n",
ptim->tm_year+1900,
ptim->tm_mon+1,
ptim->tm_mday,
ptim->tm_hour,
ptim->tm_min,
ptim->tm_sec);
//获取写操作锁
pthread_rwlock_wrlock(&rwlock);
//打开一个文件，如果不存在则创建
FILE *fp = fopen("./a.txt","w+");
//将buf里的内容写入文件
fwrite(buf,1,strlen(buf),fp);
fclose(fp);
//归还写操作锁
pthread_rwlock_unlock(&rwlock);
sleep(6);
}
return 0;
}

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