Question

所以我有这个主要功能，bank1.c：

#include<stdio.h>
#include<string.h>
#include<pthread.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/ipc.h>
#include<sys/msg.h>
#include<signal.h>
#include<sys/stat.h>
#include"receive_message.h"

int desks = 10;
int N = 2;
int running = 0;
pthread_t tid[10];
int queue[10];
int balance = 20;
pthread_mutex_t lock;

void* getMessage(void *arg)
{
    int i;
    char* message = malloc(sizeof(char)*30);
    char** m_point = &message;
    key_t key;
    pthread_mutex_lock(&lock);
    pthread_t id = pthread_self();
    pid_t pid;    
    int j = 10;

    for(i = 0; i < N; i++)
    {
        if(pthread_equal(id, tid[i]))
        {
        key = 10 + i * 5;
            printf("\n Thread %d processing\n", i);
        m_point = receive_message(key, m_point);
            printf(" Message received: %s\n", *m_point);
    }
    }
    free(message);

    pthread_mutex_unlock(&lock);
    running = running - 1;
    return NULL;

}

int main(void)
{
    int i = 0;
    int err;

    if (pthread_mutex_init(&lock, NULL) != 0)
    {
        printf("\n mutex init failed\n");
        return 1;
    }

    while(i < N)
    {
    running = running + 1;
    pthread_create(&(tid[i]), NULL, &getMessage, NULL);
        i++;

    }


    while(running != 0)
    {
    //sleep(2);
    }
    printf(" RUN OK\n");
    return 0;
}

我意识到我需要在其他文件中使用函数“receive_message”，所以我试图从中创建一个单独的文件receive_message.c：

#include<stdio.h>
#include<string.h>
#include<pthread.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/ipc.h>
#include<sys/msg.h>
#include<signal.h>
#include<sys/stat.h>

#define MSGSZ     128

struct msgbuf {
    long mtype;       
    char mtext[200];    
};

char** receive_message(key_t key, char** ret)
{

    int msqid;
    msqid = msgget((key_t) key, 0600 | IPC_CREAT);
    struct msqid_ds buf;
    struct msgbuf m_buf;

    int rc = msgctl(msqid, IPC_STAT, &buf);
    int msg = (uint)(buf.msg_qnum);


    if (msg != 0){ 

        if ((msqid = msgget(key, 0644)) == -1) { /* connect to the queue */
            perror("msgget");
            return ret;
         }

        if (msgrcv(msqid, &m_buf, sizeof m_buf.mtext, 0, 0) == -1) {
            perror("msgrcv");
        return ret;
         }
    }

    strcpy(*ret, m_buf.mtext);
    return ret;

}

使用此标题，receive_message.h：

#ifndef RECEIVE_MESSAGE_H_INCLUDED
#define RECEIVE_MESSAGE_H_INCLUDED

struct msgbuf {
    long mtype;       /* message type, must be > 0 */
    char mtext[200];    /* message data */
};

char** receive_message(key_t key, char** ret)

#endif

现在当我尝试将其编译为gcc bank1.c receive_message.c -o bank1 -lpthread时，我得到了这些错误，我无法做出正面或反面：

bank1.c: In function ‘receive_message’:
bank1.c:15:1: error: parameter ‘desks’ is initialized
 int desks = 10;
 ^
bank1.c:16:1: error: parameter ‘N’ is initialized
 int N = 2;
 ^
bank1.c:17:1: error: parameter ‘running’ is initialized
 int running = 0;
 ^
bank1.c:20:1: error: parameter ‘balance’ is initialized
 int balance = 20;
 ^
bank1.c:24:1: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
 {
 ^
bank1.c:55:1: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
 {
 ^
In file included from bank1.c:11:0:
receive_message.h:9:8: error: old-style parameter declarations in prototyped function definition
 char** receive_message(key_t key, char** ret)
        ^
bank1.c:87:1: error: expected ‘{’ at end of input
 }
 ^

我认为错误是在头文件中，但我不确定。当receive_message.c中的代码位于bank1.c

时，文件按预期运行

Answer 1

不幸的是我不能评论所以这里是Michiel已经指出的补充：

请务必仅定义struct msgbuf一次。现在它在头文件和.c文件中定义。此外，您似乎还需要在.c文件中使用它，因此您可以在.c文件中将其声明为静态而不是在头文件中公开！

将函数移动到自己的文件时出现多个错误

1 个答案: