UNIX环境高级编程学习之第十一章线程-使用读写锁
[code lang=”cpp”]/*
FileName: rwlock.c
Date: 20100310
Desc: g++ rwlock.c -lpthread -o demo
使用读写锁, 在读大于写情况下使用读写锁
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <signal.h>
int isRun = 1; // 程序运行标志
struct ConfigInfo{
pthread_rwlock_t rwlock;
char path[128+1];
int timeout;
};
void* thread_fun(void * arg)
{
struct ConfigInfo* p = (struct ConfigInfo*)arg;
while (isRun)
{
pthread_rwlock_rdlock(&p->rwlock); // 加读锁
printf("tid=%ul, path=%s, timeout=%d/n", pthread_self(), p->path, p->timeout);
pthread_rwlock_unlock(&p->rwlock); // 解锁
sleep(2);
}
return (void*)1;
}
void sig_fun(int signo)
{
isRun = 0;
}
int main(int argc, char* argv[])
{
signal(SIGINT, sig_fun);
int i, ret;
pthread_t tid[10];
struct ConfigInfo info;
pthread_rwlock_init(&info.rwlock, NULL); // 初始化读写锁
for (i = 0;i < 10;i++)
{
ret = pthread_create(&tid[i], NULL, thread_fun, (void*)&info);
if (ret != 0)
{
printf("%d. pthread_create() is Error/n", i);
exit(-1);
}
}
i = 0;
while (isRun)
{
if (i++%5 == 0) // 某情况下,修改读写锁保护的数据结构。
{
pthread_rwlock_wrlock(&info.rwlock); // 加写锁
memset(info.path, 0x00, sizeof(info.path));
strcpy(info.path, "/home/pc/a.txt");
info.timeout = i%8;
pthread_rwlock_unlock(&info.rwlock); // 解锁
}
sleep(1);
}
for (i = 0;i < 10;i++)
{
ret = pthread_join(tid[i], NULL);
if (ret != 0)
{
printf("%d. pthread_join() is Error/n", i);
exit(-1);
}
}
pthread_rwlock_destroy(&info.rwlock); // 销毁读写锁
return 0;
}

[/code]

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