QNC IPC---msg send receive example

Disclaimer: This article is a blogger original article, shall not be reproduced without the bloggers allowed. https://blog.csdn.net/yuewen2008/article/details/86375835

Sample Code qnx inter-process communication
msg_receive_server.c implements the server side data reception function, and returns the reply message to the client.
msg_send_client.c implements client-side functionality of data transmission, transmits the data to the server side and waits for a reply message server.

data server. 1 and data2 are transmitted to client, client to the data received replay message returned after data3 1, client receives a return message data. 4 replay after 2 data.

msg_send_client.c

#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/dispatch.h>

#define ATTACH_POINT "myname"

/* We specify the header as being at least a pulse */
typedef struct _pulse msg_header_t;

/* Our real data comes after the header */
typedef struct _my_data {
    msg_header_t hdr;
    int data;
} my_data_t;

/*** Client Side of the code ***/
int client() 
{
    my_data_t msg;
	int msg_reply;
    int server_coid;

    if ((server_coid = name_open(ATTACH_POINT, 0)) == -1) {
		printf("client name open failed\n");
        return EXIT_FAILURE;
    }

    /* We would have pre-defined data to stuff here */
    msg.hdr.type = 0x00;
    msg.hdr.subtype = 0x00;
	msg.data = 1;

    /* Do whatever work you wanted with server connection */
    printf("client name open success, Client sending msg %d \n", msg.data);
    if (MsgSend(server_coid, &msg, sizeof(msg), &msg_reply, sizeof(msg_reply)) == -1) {
		printf("client send msg 1 error\n");    
	}
	
    printf("client receive msg 1 reply: %d \n", msg_reply);
	
	msg.hdr.type = 0x00;
    msg.hdr.subtype = 0x01;
	msg.data = 2;
	printf("client name open success, Client sending msg %d \n", msg.data);
	if (MsgSend(server_coid, &msg, sizeof(msg), &msg_reply, sizeof(msg_reply)) == -1) {
		printf("client send msg 2 error\n");    
	}
	
    printf("client receive msg 2 reply: %d \n", msg_reply);
	
    /* Close the connection */
    name_close(server_coid);
    return EXIT_SUCCESS;
}

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

    if (argc < 2) {
        printf("Usage %s -s | -c \n", argv[0]);
        ret = EXIT_FAILURE;
    }
    else if (strcmp(argv[1], "-c") == 0) {
        printf("Running client ... \n");
        ret = client();
    }
	else {
        printf("Usage %s -s | -c \n", argv[0]);
        ret = EXIT_FAILURE;
    }
    return ret;


	
}

msg_receive_server.c

#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/dispatch.h>

#define ATTACH_POINT "myname"

/* We specify the header as being at least a pulse */
typedef struct _pulse msg_header_t;

/* Our real data comes after the header */
typedef struct _my_data {
    msg_header_t hdr;
    int data;
} my_data_t;

int msg_update_fail =3;
int msg_update_success =4;

/*** Server Side of the code ***/
int server() {
   name_attach_t *attach;
   my_data_t msg;

   
   my_data_t msg_reply;
   msg_reply.hdr.type = 0x00;
   msg_reply.hdr.subtype = 0x00;
   
  // my_data_t msg_replaydata;
   int rcvid;

   /* Create a local name (/dev/name/local/...) */
   if ((attach = name_attach(NULL, ATTACH_POINT, 0)) == NULL) {
   		printf("server name_attach error\n");
       return EXIT_FAILURE;
   }
   printf("server name_attach suceess,wait masg from client\n");

   /* Do your MsgReceive's here now with the chid */
   while (1) {
       rcvid = MsgReceive(attach->chid, &msg, sizeof(msg), NULL);

       if (rcvid == -1) {/* Error condition, exit */
           break;
       }
       /* A message (presumable ours) received, handle */
	   switch(msg.data){

			case 1:
				printf("Server receive msg data %d \n", msg.data);
				MsgReply(rcvid, EOK, &msg_update_fail, sizeof(msg_update_fail));
				//MsgReply(UpdateReceiveId, EOK, &msg_update_fail, 0);
				break;
			case 2:
				printf("Server receive msg data %d \n", msg.data);		
				MsgReply(rcvid, EOK, &msg_update_success, sizeof(msg_update_success));
				break;
			default:
				break;
	   }
	   
       MsgReply(rcvid, EOK, 0, 0);

   }

   /* Remove the name from the space */
   name_detach(attach, 0);

   return EXIT_SUCCESS;
}

int main(int argc, char **argv) {
    int ret;

    if (argc < 2) {
        printf("Usage %s -s | -c \n", argv[0]);
        ret = EXIT_FAILURE;
    }
    else if (strcmp(argv[1], "-s") == 0) {
        printf("Running Server ... \n");
        ret = server();
    }
	else {
        printf("Usage %s -s | -c \n", argv[0]);
        ret = EXIT_FAILURE;
    }
    return ret;
}