C中共享内存生产者消费者

Question

我必须通过共享内存和信号量来实现生产者 - 消费者问题。它应该从input.txt文件获取输入并将其保存到output.txt文件。保存信息的过程应在终端显示。我猜，我有同步问题。当我在里面调用fork()然后调用execl() producer.c文件时，程序似乎没有响应。生产者（至少）之前正在工作，但在修改某些代码行时，它停止了工作，我无法解决它。这是一段代码：

#include <stdio.h>      // main.c
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
#include <time.h>   
#include "semaphore.h"
#include "memory.h"

#define SIZE 10

typedef struct cyclicalBuf 
{
    int size;
    char bufor[SIZE];
}   cyclicalBuf;

int main(int argc, char *argv[])
{
    if(argc != 1) 
    {
        perror("Need no arguments!");
        exit(1);
    }

    int semid;
    int memoryID;

    int key;

    key = semGetKey('A');
    semid = semCreate(key, 2); // 2 sem made

    setVal(semid, 0, SIZE); 
    setVal(semid, 1, 0); 

    memoryID = memoryCreate('A', sizeof(cyclicalBuf)); 

    pid_t pid;
    pid = fork();

    switch(pid) 
    { 
        case -1:
            perror("fork() error in producer section");
            exit(2);
            break;
        case 0:
            execl("./producer", "./producer", NULL);
            perror("execl() error in producer section");
            exit(3);
            break;
        default:
            break;
    }

    sleep(1);

    switch(pid) 
    {
        case -1:
            perror("fork() error in consumer section");
            exit(4);
            break;
        case 0:
            execl("./consumer", "./consumer", NULL);
            perror("execl() error in consumer section");
            exit(5);
            break;
        default:
            break;
    }

    int i;
    for(i = 0; i < 2; i++) 
    {
        if(wait(0) < 0 ) 
        {
            perror("wait() error [main.c]");
        }
    }

    semDelete(semid, 2); 

    memoryDelete(memoryID); 

    return 0;
}


#include <stdio.h>        // producer.c
#include <stdlib.h>      
#include <unistd.h>   
#include <time.h>     
#include "memory.h"
#include "semaphore.h"

#define SIZE 10

typedef struct cyclicalBuf 
{
    int size;
    char bufor[SIZE];
} cyclicalBuf;

void producer() 
{
    FILE *fp;
    int i;
    int semid;
    int memoryID;
    cyclicalBuf * buf;
    char c;

    if((fp = fopen("./input.txt", "r")) == NULL) 
    { 
        perror("fopen() error [producer]");
        exit(1);
    }

    int key;

    key = semGetKey('A');
    semid = semCreate(key, 2); y

    memoryID = memoryAccess('A');

    buf = (cyclicalBuf *)memoryLink(memoryID);

    printf("Producer: ");

    for(i = 0; (c = fgetc(fp)) != EOF; i++) 
    {

        semRelease(semid, 0); 

        usleep(rand()%5555);

        buf->bufor[i%SIZE] = c; 

        buf->size++;

        semAcquire(semid, 1); 

        printf(" %c", c); 
    }

    if(fclose(fp) == EOF) 
    {
        perror("fclose() error [producer]");
        exit(2);
    }

    memoryUnlink(buf);
}

int main(int argc, char *argv[]) 
{

    if(argc != 1) 
    {
        perror("Need no arguments!");
        exit(3);
    }

    srand(time(NULL));

    producer();     

    return 0;
}


#include <stdio.h>   // consumer.c
#include <stdlib.h>    
#include <unistd.h>    
#include <time.h>       
#include <sys/sem.h>   
#include "memory.h"
#include "semaphore.h"

#define SIZE 10

typedef struct cyclicalBuf 
{
    int size;
    char bufor[SIZE];
} cyclicalBuf;

void consumer() 
{
    FILE *fp;
    int c_cnt = 0;
    int i = 0;
    int semid;
    int memoryID;
    cyclicalBuf * buf;
    char c;

    if((fp = fopen("./output.txt", "w")) == NULL) 
    { 
        perror("fopen() error [consumer]");
        exit(1);
    }

    int key;

    key = semGetKey('A');
    semid = semCreate(key, 2); 

    memoryID = memoryAccess('A');

    buf = (cyclicalBuf *)memoryLink(memoryID); 

    printf("Consumer: ");

    while(!((semctl(semid, 0, GETVAL) == SIZE) && (c_cnt == buf->size))) 
    {

        semRelease(semid, 1);  

        usleep(rand()%5555);

        c = buf->bufor[i%SIZE]; 

        semAcquire(semid, 0); 

        fputc(c, fp); 

        printf(" %c", c); 

        i++;
        c_cnt++;
    }

    if(fclose(fp) == EOF) // 
    { 
        perror("fclose() error [consumer]");
        exit(2);
    }

    memoryUnlink(buf); // 
}

int main(int argc, char *argv[]) 
{

    if(argc != 1) 
    {
        perror("Need no arguments!");
        exit(3);
    }

    srand(time(NULL));

    consumer();

    return 0;
}

如果需要，我可以提供信号量和共享内存功能。

OUTPUT:
./main
|  --> this is just blinking cursor, nothing happens