利用pthread_cond_signal和pthread_cond_wait实现c语言代码,功能要求为:创建三个线程,线程函数名分别为zero,even,odd,用来交替打印0、基数、偶数,实现打印结果如01020304050607
时间: 2024-04-08 21:29:49 浏览: 126
下面是一个示例的C语言代码,使用pthread_cond_signal和pthread_cond_wait实现交替打印0、基数和偶数的功能:
```c
#include <stdio.h>
#include <pthread.h>
pthread_mutex_t mutex;
pthread_cond_t cond_zero, cond_even, cond_odd;
int count = 0;
void* zero(void* arg) {
while (count <= 7) {
pthread_mutex_lock(&mutex);
if (count == 0) {
printf("0");
count++;
pthread_cond_signal(&cond_even);
}
else {
pthread_cond_wait(&cond_zero, &mutex);
}
pthread_mutex_unlock(&mutex);
}
return NULL;
}
void* even(void* arg) {
while (count <= 7) {
pthread_mutex_lock(&mutex);
if (count % 2 == 0 && count != 0) {
printf("%d", count);
count++;
pthread_cond_signal(&cond_odd);
}
else {
pthread_cond_wait(&cond_even, &mutex);
}
pthread_mutex_unlock(&mutex);
}
return NULL;
}
void* odd(void* arg) {
while (count <= 7) {
pthread_mutex_lock(&mutex);
if (count % 2 != 0) {
printf("%d", count);
count++;
pthread_cond_signal(&cond_zero);
}
else {
pthread_cond_wait(&cond_odd, &mutex);
}
pthread_mutex_unlock(&mutex);
}
return NULL;
}
int main() {
pthread_t threads[3];
pthread_mutex_init(&mutex, NULL);
pthread_cond_init(&cond_zero, NULL);
pthread_cond_init(&cond_even, NULL);
pthread_cond_init(&cond_odd, NULL);
pthread_create(&threads[0], NULL, zero, NULL);
pthread_create(&threads[1], NULL, even, NULL);
pthread_create(&threads[2], NULL, odd, NULL);
for (int i = 0; i < 3; i++) {
pthread_join(threads[i], NULL);
}
pthread_mutex_destroy(&mutex);
pthread_cond_destroy(&cond_zero);
pthread_cond_destroy(&cond_even);
pthread_cond_destroy(&cond_odd);
printf("\n");
return 0;
}
```
在这个示例中,我们创建了三个线程分别代表打印0、偶数和奇数的功能。每个线程函数中,我们使用了互斥锁来保护共享变量count,并使用条件变量来进行线程的阻塞和唤醒。
- zero线程打印0,并发送信号给even线程。
- even线程打印偶数,并发送信号给odd线程。
- odd线程打印奇数,并发送信号给zero线程。
通过调用pthread_cond_wait和pthread_cond_signal来实现线程间的交替打印。在主线程中,我们使用pthread_join来等待所有子线程的结束,以确保打印完所有数字之后再打印换行符。
注意,我们需要分别创建和销毁三个条件变量:cond_zero、cond_even和cond_odd。
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