进程间通讯之消息队列

#include<stdio.h>

#include<sys/msg.h>

#define MAX_MSG_BUF_LEN    512

int iKey = 6004;

struct ipcmsgbuf

{

long mtype;

char mtext[MAX_MSG_BUF_LEN];

};

int main( void )

{

int qid;

char sTmp[128], sTmp2[128], sTmp3[128];

struct ipcmsgbuf msgdata;

memset( sTmp, 0, sizeof(sTmp) );

memset( sTmp2, 0, sizeof(sTmp2) );

memset( sTmp3, 0, sizeof(sTmp3) );

if( (qid = msgget(iKey, 0000)) < 0 )

{

printf("0000\n");

qid = msgget( iKey, IPC_CREAT|0660 );

if( qid < 0 )

{

printf( "msgget error!\n" );

return -1;

}

}

/* 写消息队列 */

memset( &msgdata, 0, sizeof( struct ipcmsgbuf ) );

msgdata.mtype = 1;

memcpy( msgdata.mtext, "abcdefg", 7 );

msgsnd( qid, &msgdata, 7, 0 );

/* 写消息队列 */

memset( &msgdata, 0, sizeof( struct ipcmsgbuf ) );

msgdata.mtype = 2;

memcpy( msgdata.mtext, "1234567", 7 );

msgsnd( qid, &msgdata, 7, 0 );

/* 读消息队列 */

memset( &msgdata, 0, sizeof( struct ipcmsgbuf ) );

msgrcv( qid, &msgdata, 7, 1, 0 );

memcpy( sTmp, msgdata.mtext, 7 );

printf( "sTmp=%s\n", sTmp );

/* 读消息队列 */

memset( &msgdata, 0, sizeof( struct ipcmsgbuf ) );

msgrcv( qid, &msgdata, 7, 2, 0 );

memcpy( sTmp2, msgdata.mtext, 7 );

printf( "sTmp2=%s\n", sTmp2 );

/* 读消息队列 */

memset( &msgdata, 0, sizeof( struct ipcmsgbuf ) );

msgrcv( qid, &msgdata, 7, 2, IPC_NOWAIT );

memcpy( sTmp3, msgdata.mtext, 7 );

printf( "sTmp3=%s\n", sTmp3 );

/* 从系统中删除该消息队列以及仍在该队列上的所有数据 */

msgctl( qid, IPC_RMID, 0 );

return 0;

}

运行结果：

0000

sTmp=abcdefg

sTmp2=1234567

sTmp3=

进程间通讯之消息队列