Semaphore Fmutex=1,Asem=0,Bsem=0;
int c1=c2=0;
Cobegin
Pa(i=1,2,3...){P(Asem)c1++;if(c1==1)P(Fmutex)V(Asem)reading F;P(Asem)c1--;if(c1==0)V(Fmutex)V(Asem)
}
Pb(i=1,2,3...){P(Bsem)c2++;if(c2==1)P(Fmutex)V(Bsem)reading F;P(Bsem)c2--;if(c2==0)V(Fmutex)V(Bsem)
}
coend

Semaphore mutex=1,sem13=1,sem24=1;
int c1=2=0;
cobegin
p1(){P(sem13)c1++;if(c1=1) P(mutex)V(sem13)P1通过路口;P(sem13)c1--;if(c1==0)V(mutex)V(sem13)
}
p2(){P(sem24)c2++;if(c2==1)P(mutex)V(sem24)P2通过路口;P(sem24)c2--;if(c2==0)V(mutex)V(sem24)
}
p3(){P(sem13)c1++;if(c1=1) P(mutex)V(sem13)P3通过路口;P(sem13)c1--;if(c1==0)V(mutex)V(sem13)
}
p4(){P(sem24)c2++;if(c2==1)P(mutex)V(sem24)P4通过路口;P(sem24)c2--;if(c2==0)V(mutex)V(sem24)
}
coend

int m1=2,m2=0,m3=0;
cobegin
p1(){while(1){洗桔子；P(m1);放桔子；V(m3);}
}
p2(){while(1){洗苹果;P(m1);放苹果;V(m2);}
}
p3(){while(1){P(m2);取苹果;V(m1);吃苹果;}
}
p4(){while(1){P(m3);取桔子;V(m1);吃桔子;}
}
coend

semaphore Chopstick[5],5;chopstick[0].value=chopstick[1].value=1;chopstick[2].value=chopstick[3].value=1;chopstick[4].value=1;S.value=4;//最多允许4个哲学家同时拿筷子process Pi()(i=0,1,2,3,4){//第i个哲学家进程    while(true){        wait(5);//看是否允许拿筷子        wait(chopstick[i]);//拿起左边筷子        wait(chopstick[(i+1)%5]);//拿起右边筷子        eating;        signal(chopstick[i]);//放下左边筷子        signal(chopstick[(i+1)%5]);//放下右边筷子        signal(5);        thinking;    }}parbegin//进程并发执行P0();P1();P2();P3();P4();parend

semaphore chopstick[5];
chopstick[0].value=chopstick[1].value=1;
chopstick[2].value=chopstick[3].value=1;
chopstick[4].value=1;
parbegin
process Pi()(i=0,2,4){while(true){wait(chopstick[(i+1)%5]);wait(chopstick[i]);eating;signal(chopstick[(i+1)%5]);signal(chopstick[i]);thinking;}
}
process Pi()(i=1,2){while(true){wait(chopstick[i]);wait(chopstick[i+1]);eating;signal(chopstick[i]);signal(chopstick[i+1]);thinking;}
}
parend