江苏做网站价格,天津企业网站设计制作,有没有正规的毕设代做网站,国内联盟wordpress插件pc1.c: 使用条件变量解决生产者、计算者、消费者问题
/*
• 系统中有3个线程#xff1a;生产者、计算者、消费者
• 系统中有2个容量为4的缓冲区#xff1a;buffer1、buffer2
• 生产者生产a、b、c、‘d、e、f、g、h八个字符#xff0c;放入到buffer1
• 计算者从b…pc1.c: 使用条件变量解决生产者、计算者、消费者问题
/*
• 系统中有3个线程生产者、计算者、消费者
• 系统中有2个容量为4的缓冲区buffer1、buffer2
• 生产者生产a、b、c、‘d、e、f、g、h八个字符放入到buffer1
• 计算者从buffer1取出字符将小写字符转换为大写字符放入到buffer2
• 消费者从buffer2取出字符将其打印到屏幕上
实现思路设置两个大小为4的缓冲区第一个为生产者和计算着共享第二个为计算者和消费者共享。
1、生产者线程产生字符将字符写入缓冲区buffer1中并将指针后移当缓冲区被写满是将生产者线程挂起唤醒计算者线程等待缓冲区buffer1有空闲存储空间的时候再唤醒生产者线程。
2、计算者线程从buffer1中读取数据并移动指针并将读取的数据写入buffer2中当buffer1有空闲时唤醒生产者进程当buffer2被写满时唤醒消费者进程。
3、消费者进程从buffer2中读取字符并输出并移动指针当buffer2有空闲的时候唤醒计算者进程。 实现代码
#includestdio.h
#includepthread.h
#includeunistd.h#define CAPACITY 4char buffer1[4];
char buffer2[4];int crea; //生产者
int comp1;//计算者
int comp2;//计算者
int cons; //消费者 int buffer1_is_empty(){return creacomp1;
}int buffer1_is_full(){return (crea1)%CAPACITYcomp1;
}int buffer2_is_empty(){return comp2cons;
}int buffer2_is_full(){return (cons1)%CAPACITYcomp2;
}int get_item1(){int item;itembuffer1[comp1];comp1(comp11)%CAPACITY;return item;
}int get_item2(){int item;itembuffer2[cons];cons(cons1)%CAPACITY;return item;
}int put_item1(int item){buffer1[crea]item;crea(crea1)%CAPACITY;
}int put_item2(int item){buffer2[comp2]item;comp2(comp21)%CAPACITY;
}pthread_mutex_t mutex1;
pthread_cond_t wait_empty_buffer1;
pthread_cond_t wait_full_buffer1;pthread_mutex_t mutex2;
pthread_cond_t wait_empty_buffer2;
pthread_cond_t wait_full_buffer2;#define ITEM_COUNT (CAPACITY *2)void *consumer(void *arg){int i;int item;for(i0;iITEM_COUNT;i){pthread_mutex_lock(mutex2);while(buffer2_is_empty())pthread_cond_wait(wait_full_buffer2,mutex2);itemget_item2();printf( consume item:%c\n,item);pthread_cond_signal(wait_empty_buffer2);pthread_mutex_unlock(mutex2);}return NULL;
}void *computer(void *arg){int i;int item;for(i0;iITEM_COUNT;i){pthread_mutex_lock(mutex1);while(buffer1_is_empty())pthread_cond_wait(wait_full_buffer1,mutex1);itemget_item1();printf( computer get item:%c\n,item);item-32;pthread_cond_signal(wait_empty_buffer1);pthread_mutex_unlock(mutex1);pthread_mutex_lock(mutex2);while(buffer2_is_full())pthread_cond_wait(wait_empty_buffer2,mutex2);put_item2(item);printf( computer put item:%c\n,item);pthread_cond_signal(wait_full_buffer2);pthread_mutex_unlock(mutex2);}return NULL;
}void *create(void *arg){int i;int item;for(i0;iITEM_COUNT;i){pthread_mutex_lock(mutex1);while(buffer1_is_full())pthread_cond_wait(wait_empty_buffer1,mutex1);itemai;put_item1(item);printf(create item:%c\n,item);pthread_cond_signal(wait_full_buffer1);pthread_mutex_unlock(mutex1);}return NULL;
}int main(){pthread_t consumer_tid;pthread_t computer_tid;pthread_mutex_init(mutex1,NULL);pthread_mutex_init(mutex2,NULL);pthread_cond_init(wait_empty_buffer1,NULL);pthread_cond_init(wait_full_buffer1,NULL);pthread_cond_init(wait_empty_buffer2,NULL);pthread_cond_init(wait_full_buffer2,NULL);pthread_create(consumer_tid,NULL,consumer,NULL);pthread_create(computer_tid,NULL,computer,NULL);create(NULL);pthread_join(consumer_tid,NULL);pthread_join(computer_tid,NULL);pthread_mutex_destroy(mutex1);pthread_mutex_destroy(mutex2);return 0;
} 欢迎留言交流。。。
