linux 消息队列类型

喜欢ヅ旅行 2022-08-26 01:14 174阅读 0赞

linux消息队列类型不能为0，否则将会报invalid argument错误。测试代码如下，如果发送端循环从0开始将出现错误。

send.cc

/*=============================================================================
    #      Filename : send.cc
    #   Description : 发送端实现
    #        Author : chenqingming chenqingming0710@163.com
    #        create : 2014-03-20 20:48
    # Last modified : 2014-03-20 20:48
    =============================================================================*/
    
    #include <stdio.h>
    #include <stdlib.h>
    #include <sys/ipc.h>
    #include <sys/msg.h>
    #include <errno.h>
    #include <string.h>
    
    #include "data_type.hpp"
    
    #define SEND_COUNT 1000
    
    int main()
    {
        int status = -1;
        int msg_id = -1;
        int i;
        key_t ipc_key = (key_t)-1;
    
        //获取键值
        ipc_key = get_ipc_key();
        if (ipc_key == (key_t)-1)
        {
            fputs("get ipc_id fail\n", stdout);
            exit(1);
        }
    
        //创建消息队列
        msg_id = msgget(ipc_key, 0777|IPC_CREAT);
        if (msg_id == -1)
        {
            fputs("create msg fail\n", stdout);
            exit(2);
        }
    
        //发送消息
        msg_struct msg_data;
        for (i = 0; i < SEND_COUNT; ++i)
        {
            msg_data.msg_type = i+1;
            int j;
            for (j = 0; j < i + 1; ++j)
            {
                msg_data.msg[j] = 'A';
            }
            msg_data.msg[j] = '\0';
    
            //send
            status = msgsnd(msg_id, (void*)&msg_data, MAX_MSG_LENGTH, 0);
            if (status == -1)
            {
                printf("%s\n", strerror(errno));
                fputs("send error\n", stdout);
                exit(1);
            }
        }
        fputs("send over\n", stdout);
        exit(EXIT_SUCCESS);
    }

get.cc

#include <stdio.h>
    #include <stdlib.h>
    #include <sys/msg.h>
    #include <sys/ipc.h>
    
    #include "data_type.hpp"
    #define GET_COUNT 1000
    
    int main()
    {
        key_t ipc_id = get_ipc_key();
        if (ipc_id == (key_t)-1)
          exit(1);
    
        int msg_id = msgget(ipc_id, 0777|IPC_CREAT);
        if (msg_id == -1)
          exit(2);
    
        msg_struct msg_data;
        fputs("start gen msg\n", stdout);
        while (1)
        {
            if (msgrcv(msg_id, &msg_data, MAX_MSG_LENGTH, 0, 0) == -1)
              exit(2);
    
            printf("%ld\n", msg_data.msg_type);
            //fputs(msg_data.msg, stdout);
            if (msg_data.msg_type == GET_COUNT - 1)
              break;
        }
        
        printf("get over :%ld\n", msg_data.msg_type);
        exit(EXIT_SUCCESS);
    }