当延迟（）存在时程序中的饥饿。 C编程

Question

我正在尝试使用pthreads和信号量解决男女皆宜的浴室问题。我已经将停顿数设置为3，如male和female_multiplex中所示。我的问题是当我在“女人和女人”或“男人和男人”之间添加延迟（）时，饥饿就会发生。我希望该计划能够同时处理3个同性别的人。之后，浴室应改变性别并容纳异性。所以代码应该以3-3-3-3模式运行，具有交替的性别。 请帮帮我。谢谢！

#define _REENTRANT

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <time.h>
#include <pthread.h>
#include <semaphore.h>

void *male(void *);
void *female(void *);

sem_t empty;                                // controls access to the bathroom
sem_t male_mutex;                           // mutex for male_counter
sem_t male_multiplex;                       // limits # of men in the bathroom
int male_counter = 0;                       // # of men in bathroom or waiting
sem_t female_mutex;                         // mutex for female_counter
sem_t female_multiplex;                     // limits # of women in the bathroom
int female_counter = 0;                     // # of women in bathroom or waiting

void delay(void)
{
    int i;
    int delaytime;
    delaytime = random();
    for (i = 0; i<delaytime; i++);
}

void *male(void *param){

    sem_wait(&male_mutex);
    male_counter++;
    if(male_counter == 1){
        sem_wait(&empty);                   // make this a male bathroom or wait
    }
    sem_post(&male_mutex);

    sem_wait(&male_multiplex);               // limit # of people in the bathroom
    printf("man in!\n");
    delay();
    printf("man out!\n");
    sem_post(&male_multiplex);              // let the next one in

    sem_wait(&male_mutex);
    male_counter--;
    if (male_counter == 0){
        sem_post(&empty);                   // may become female bathroom now
    }
    sem_post(&male_mutex);
}

void *female(void *param){

    sem_wait(&female_mutex);
    female_counter++;
    if(female_counter == 1){
        sem_wait(&empty);                   // make this a female bathroom or wait
    }
    sem_post(&female_mutex);

    sem_wait(&female_multiplex);               // limit # of people in the bathroom
    printf("woman in!\n");
    delay();
    printf("woman out!\n");
    sem_post(&female_multiplex);              // let the next one in

    sem_wait(&female_mutex);
    female_counter--;
    if (female_counter == 0){
        sem_post(&empty);                   // may become male bathroom now
    }
    sem_post(&female_mutex);
}

int main(void){
    int i;
    int x;
    int t;

    srand(time(NULL));
    int a[100]={};
    printf("enter: ");
    scanf("%d",&t);

    for(i=0;i<t;i++){
        a[i] = rand()%2;
    }

    for(i=0;i<t;i++){
        printf("%d", a[i]);
    }
    printf("\n");

    sem_init(&empty, 0, 1);
    sem_init(&male_mutex, 0, 1);
    sem_init(&male_multiplex, 0, 3);
    sem_init(&female_mutex, 0, 1);
    sem_init(&female_multiplex, 0, 3);

    pthread_t *tid;
    tid = malloc(80*sizeof(pthread_t));

    for(i=0;i<t;i++){

        if(a[i] == 0){
            pthread_create(&tid[i],NULL,female,NULL);
        }
        else{
            pthread_create(&tid[i],NULL,male,NULL);
        }
    }

    for(i=0;i<t;i++){
        pthread_join(tid[i],NULL);
    }

    return(0);
}