Linux訊息佇列實踐(3)

標籤：linux   ipc   訊息佇列   處理序間通訊   cc++   

API綜合使用

//父進程發送訊息,子進程接收訊息struct msgBuf{    long mtype;       /* message type, must be > 0 */    char mtext[104];    /* message data */};const int MSGNUMBER = 10;int main(){    //擷取一個鍵    key_t msgKey = ftok("/tmp/mySeedFile",‘f‘);    //擷取一個訊息佇列    int msgid = msgget(msgKey,IPC_CREAT|0666);    if (msgid == -1)    {        err_exit("msgget error");    }    struct msgBuf myBuffer;    pid_t pid = fork();    if (pid == -1)    {        err_exit("fork error");    }    //父進程,發送資料    if (pid > 0)    {        myBuffer.mtype = getpid();        //向訊息佇列中發送訊息,如果隊列full,則該進程一直阻塞        for (int i = 0; i < MSGNUMBER; ++i)        {            sprintf(myBuffer.mtext,"Hello, My Number is %d",i);            msgsnd(msgid,&myBuffer,strlen(myBuffer.mtext),0);        }　　//等待子進程結束        wait(NULL);    }    else if (pid == 0)  //子進程　　{　　//睡眠1秒,等待父進程發送結束        sleep(1);        memset(&myBuffer,0,sizeof(myBuffer));        //從隊首不斷的取資料        for (int i = 0; i < MSGNUMBER; ++i)        {            int recvBytes = 0;            if ((recvBytes = msgrcv(msgid,&myBuffer,sizeof(myBuffer.mtext),                                    getppid(),IPC_NOWAIT)) == -1)            {                err_exit("msgrcv error");            }            else            {                cout << "recvBytes = " << recvBytes << endl;                cout << "myBuffer.mtype = " << myBuffer.mtype << endl;                cout << "\t" << myBuffer.mtext << endl;            }        }        cout << "strlen(myBuffer.mtext) = " << strlen(myBuffer.mtext) << endl;    }    return 0;}

訊息佇列項目開發案例

訊息佇列實現回射客戶/伺服器

/**一個簡化實現->程式說明:　　1.用戶端發送資料格式:　　類型為:用戶端pid　　內容為鍵盤輸入的內容2.用戶端接收格式　　類型為自己的pid　　內容為伺服器發送過來的內容　　3.伺服器接收的資料　　類型為用戶端pid　　內容為各個用戶端的訊息內容　　4.伺服器發送的資料　　類型為用戶端id　　內容為用戶端訊息內容*/

//server.cpp#include "commen.h"void echo_server(int msgid){    struct msgBuf myMsgBuf;    while (true)    {        memset(&myMsgBuf,0,sizeof(myMsgBuf));        int recvBytes = msgrcv(msgid,&myMsgBuf,MAXMSGSIZE,0,0);        if (recvBytes == -1)        {            err_exit("msgrcv error");        }        fputs(myMsgBuf.mtext,stdout);        if (msgsnd(msgid,&myMsgBuf,strlen(myMsgBuf.mtext),0) < 0)        {            err_exit("msgsnd error");        }    }}int main(){    key_t key = ftok(FILESEED,‘f‘);    int msgid = msgget(key,0666|IPC_CREAT);    if (msgid == -1)    {        err_exit("msgget error");    }    echo_server(msgid);    return 0;}

//client.cpp#include "commen.h"void echo_client(int msgid){    struct msgBuf myMsgBuf,recvMsgBuf;    myMsgBuf.mtype = getpid();    while (fgets(myMsgBuf.mtext,MAXMSGSIZE,stdin) != NULL)    {        if (msgsnd(msgid,&myMsgBuf,strlen(myMsgBuf.mtext),0) == -1)        {            err_exit("msgsnd error");        }        memset(&recvMsgBuf,0,sizeof(recvMsgBuf));        if (msgrcv(msgid,&recvMsgBuf,sizeof(recvMsgBuf),getpid(),0) == -1)        {            err_exit("msgrcv error");        }        fputs(recvMsgBuf.mtext,stdout);        memset(&myMsgBuf+4,0,sizeof(myMsgBuf)-4);    }}int main(){    key_t key = ftok(FILESEED,‘f‘);    int msgid = msgget(key,0666);    if (msgid == -1)    {        err_exit("msgget error");    }    echo_client(msgid);    return 0;}

//commen.h#ifndef COMMEN_H_INCLUDED#define COMMEN_H_INCLUDED#include <string>#include <string.h>#include <errno.h>#include <stdlib.h>#include <stdio.h>const char FILESEED[] = "/tmp/mySeedFile";const int MAXMSGSIZE = 1024;struct msgBuf{    long mtype;             //Message Type: Client PID    char mtext[MAXMSGSIZE]; //message data};void err_exit(std::string str){    perror(str.c_str());    exit(EXIT_FAILURE);}#endif // COMMEN_H_INCLUDED

開拓眼界

附-Makefile

CC = g++ CPPFLAGS = -Wall -gBIN = client server SOURCES = $(BIN.=.cpp).PHONY: clean all all: $(BIN)$(BIN): $(SOURCES)clean:    -rm -rf $(BIN) bin/ obj/ core

Linux訊息佇列實踐(3)