会python真的可以为所欲为0(回)
365天前
这里还有人吗1(回)
550天前这里还有人吗0(回)
550天前
每天面对着电脑屏幕，敲打键盘。我所面对的并不只是代码，而是一种生活方式。0(回)
775天前到处都是羊，不想上班0(回)
855天前
鸽子
0(回)
859天前#include<stdio.h> |
#include<stdlib.h> |
#include<unistd.h> |
#include<pthread.h> |
#include<semaphore.h> |
#include<fcntl.h> |
#include<errno.h> |
#define n 5 //有五把椅子 |
//三个信号量: mutex,customer,barbers |
sem_t mutex,customers,barbers; |
int waiting=0; //等待的顾客数量 |
int chair[5]; |
void * barber(); |
void * customer ( void *arg ); |
int main ( int argc,char *argv[] ) |
{ |
//创建10个顾客和1个理发师 |
pthread_t Customer_id[10],Barber_id; |
int i; |
sem_init ( &mutex,0,1 ); //互斥信号量初始化1 |
sem_init ( &customers,0,0 );//顾客信号量初始化0 |
sem_init ( &barbers,0,1 );//理发师信号量初始化1 |
for ( i=0; i<5; i++ ) |
pthread_create ( &Barber_id,NULL, ( void* ) barber,NULL ); |
for ( i=0; i<10; i++ ) |
pthread_create ( &Customer_id[i],NULL, ( void* ) customer, ( void* ) ( i+1 ) ); |
for ( i=0; i<10; i++ ) |
pthread_join ( Customer_id[i],NULL ); |
for ( i=0; i<5; i++ ) |
pthread_join ( Barber_id,NULL ); |
return 0; |
} |
//创建理发师线程 |
void * barber() |
{ |
int i; |
int next; |
//等待顾客，如果没有顾客，理发师睡觉 |
sem_wait ( &customers ); |
sem_wait ( &mutex ); //等待互斥锁释放 |
waiting--; //等待的顾客减1 |
for ( i=0; i<5; i++ ) |
{ |
if ( chair[i]!=0 ) |
{ |
next= chair[i]; |
chair[i]=0; |
break; |
} |
} |
printf ( "The barber is cutting %dth customer's hair\n",next ); |
sleep ( 3 ); |
sem_post ( &mutex ); |
sem_post ( &barbers ); |
} |
//创建顾客线程 |
void * customer ( void *arg ) |
{ |
int i; |
sem_wait ( &mutex ); //等待互斥锁释放 |
if ( waiting<n ) |
{ |
waiting++; //等待的顾客加1 |
for ( i=0; i<5; i++ ) |
{ |
if ( chair[i]==0 ) |
{ |
chair[i]= ( int ) arg; |
break; |
} |
} |
printf ( "***************************************************\n" ); |
printf ( "Entered:Number %d customer comes,and sits at %d chair \n", ( int ) arg, ( i+1 ) ); |
printf ( "There are %d customer on the chair\n",waiting ); |
printf ( "The customers' location are:" ); |
for ( i=0; i<5; i++ ) |
printf ( "%d ",chair[i] ); |
printf ( "\n" ); |
sleep ( 1 ); |
sem_post ( &mutex ); //释放互斥锁 |
sem_post ( &customers ); |
sem_wait ( &barbers ); //理发师等待 |
} |
else |
{ |
printf ( "Number %d comes,there are no chairs,the customer %d is leaving\n", ( int ) arg, ( int ) arg ); |
sem_post ( &mutex ); |
} |
} |
