c语言中的一些函数常用方法

1.创建线程

1.创建线程
(linux)
//thread.c
#include
#include
#include
void * new_thread(void * args)
{
       int i=0;
       int *p=(int *) args;
       while(i++<10){
               sleep(1);
               printf("I am wake up now and will sleep agin ");
       }

}
int main()
{
pthread_t thread;
       int i=0;
       pthread_create(&thread,NULL,new_thread,&i);
       pthread_join(thread,NULL);
}
编译命令如下 gcc thread.c -lpthread

(window)
#include
#include
#include
DWORD WINAPI new_thread( void * parm)
{
    cout<<"hello<<\n";
    return 0;
}
void main()
{
    DWORD dwThread;
    CreateThread(NULL,0,new_thread,NULL,0,&dwThread);
    Sleep(10);//不能少，少了就看不到输出的效果了。
}

2.线成同步：
#include
#include
#include
int buff[16];
int num;
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
void * producer(void * args){
        //int i=produce();
//      int i=pthread_mutex_trylock(&mutex);
        pthread_mutex_lock(&mutex);
        sleep(1);
        printf("producer finished work ");
        pthread_mutex_unlock(&mutex);

}
void *  user(void * args){
        int i=pthread_mutex_trylock(&mutex);
//      if(i==EBUSY)
//              printf("the mutex is locked ");
        printf("the mutex should be locked,does it show quicker ");
        pthread_mutex_lock(&mutex);
        printf("int user function ");
        pthread_mutex_unlock(&mutex);

}
int main()
{
        int i=0;
        pthread_t pro,usr;
        pthread_create(&pro,NULL,producer,&i);
        pthread_create(&usr,NULL,user,&i);
        pthread_join(pro,NULL);
        pthread_join(usr,NULL);
}

3. 线程signal

#include
#include
#include

pthread_mutex_t mutex;
pthread_cond_t  cond;

int num=0;
void * child1(void *arg)
{
        pthread_cleanup_push(pthread_mutex_unlock,&mutex);  /* comment 1 */
        while(1){
                printf("thread 1 get running \n");
                printf("thread 1 pthread_mutex_lock returns %d\n",pthread_mutex_lock(&mutex));
                pthread_cond_wait(&cond,&mutex);
                printf("thread 1 condition applied\n");
                pthread_mutex_unlock(&mutex);
                sleep(5);
        }
        }
        pthread_cleanup_pop(0);     /* comment 2 */
}

void *child2(void *arg)
{
        while(1){
        printf("thread 2 get running.\n");
        printf("thread 2 pthread_mutex_lock returns %d\n",pthread_mutex_lock(&mutex));
        printf("thread 2 condition applied\n");
        while(num<=0){
        pthread_cond_wait(&cond,&mutex);
        }
        num--;
        pthread_mutex_unlock(&mutex);
        printf("consume one \n");
   //     sleep(1);
        }
}

int main(void)
{
    int tid1,tid2;

        printf("hello, condition variable test\n");
        pthread_mutex_init(&mutex,NULL);
        pthread_cond_init(&cond,NULL);
//        pthread_create(&tid1,NULL,child1,NULL);
        pthread_create(&tid2,NULL,child2,NULL);
        char a;
        do{
//              sleep(2);                   /* comment 4 */
//                pthread_cancel(tid1);       /* comment 5 */
//                sleep(2);                   /* comment 6 */
                scanf("%c",&a);
                pthread_mutex_lock(&mutex);
                num++;
                printf("product 1\n");
                pthread_mutex_unlock(&mutex);
                pthread_cond_signal(&cond);

        }while(1);
        sleep(100);
        pthread_exit(0);
}