C语言多线程编程《3个足球运动员》

场景：3个足球运动员练习传球。

方法：

1. A传给B，B传给C，C传给A。

2. 如此反复，踢10圈，结束练习。

技术点：

1. 线程的创建，结束，合并。

2. semaphore

编程实例：（Windows VC6.00 Console Application）

#include <pthread.h>

#include <semaphore.h> 

#pragma comment(lib, "pthreadVC2.lib")

#define PLAYERNUM 3

sem_t player[PLAYERNUM];

pthread_t pid[PLAYERNUM];

void *play(void *arg);

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

{
int i;

for(i = 0 ; i < PLAYERNUM ; i++) {
sem_init(&player[i], NULL, 0);
pthread_create(&pid[i], NULL, play, (void *)i);
}

sem_post(&player[0]);

for(i = 0 ; i < PLAYERNUM ; i++)
pthread_join(pid[i], NULL);

return 0;

}

void *play(void *arg)

{
int i;

for(i = 0 ; i < 10 ; i++) {
sem_wait(&player[(int)arg]);
printf("%d to %d\n", (int)arg, ((int)arg + 1)%PLAYERNUM);
sem_post(&player[((int)arg + 1)%PLAYERNUM]);
}

pthread_exit(NULL);

return NULL;

}

输出：

0 to 1

1 to 2

2 to 0

0 to 1

1 to 2

2 to 0

0 to 1

1 to 2

2 to 0

0 to 1

1 to 2

2 to 0

0 to 1

1 to 2

2 to 0

0 to 1

1 to 2

2 to 0

0 to 1

1 to 2

2 to 0

0 to 1

1 to 2

2 to 0

0 to 1

1 to 2

2 to 0

0 to 1

1 to 2

2 to 0

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