操作系统课程设计--用多线程同步方法解决睡眠理发师问题(Sleepin(3)

void * barber() {

int i; int next;

//wait(customers),if no customers,barber sleeping sem_wait(&customers);

sem_wait(&mutex); //wait(mutex)

waiting--; //the numer of waiting reduce one for(i=0;i<5;i++) {

if (chair[i]!=0) {

next= chair[i]; chair[i]=0; break; } }

printf(\ sleep(3); sem_post(&mutex); sem_post(&barbers); }

//creat customer pthread void * customer(void *arg) {

int i;

sem_wait(&mutex); //wait(mutex) if(waiting

if(waiting

waiting++; //the numer of waiting plus one for(i=0;i<5;i++) {

if (chair[i]==0) {

chair[i]=(int)arg; break; } }

printf(\ printf(\%d customer comes,and sits at %d \\n\

printf(\ printf(\ for(i=0;i<5;i++)

printf(\ printf(\

sleep(1);

sem_post(&mutex); //signal(mutex)

sem_post(&customers); //signal(customers) sem_wait(&barbers); //wait(barbers) } else

chair {

printf(\%d comes,there are no chairs,the customer %d is leaving\\n\ sem_post(&mutex); } }

5.2.1 编辑，编译和运行的过程图

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5.2.2 错误部分截图

5.2.3 正确运行结果图

第一次运行结果如下图：

第二次运行结果如下图：