blog/2015年10月18日/pthread - mffukui@Wiki

#blognavi

pthreadでスレッドを作って、メッセージを飛ばして、
応答を取得するサンプル

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

#define	BUFSIZE	32

struct mymsg {
	int id;
	char com[BUFSIZE];
};

/* message struct */
struct msgbuf {
      long int type;
      struct mymsg data;
};

/* global */
key_t msgkey;
int msgQID_com;
int msgQID_res;

void *test_thread(void *param)
{
	struct msgbuf message = {0};

	printf("pid=%d\n", getpid() );

	while(1){
		if( msgrcv(msgQID_com, &message, sizeof(message.data), 0, 0) == -1 ){
			printf("msgrcv err\n");
			exit(1);
		}
		printf("message rcv: id=%d data=%s\n", message.data.id, message.data.com);
		
		/* send reply */
		message.data.id = 2;
		strncpy( message.data.com, "resp1", BUFSIZE );
		if( msgsnd(msgQID_res, &message, sizeof(message.data), 0) == -1 ){
			printf("msgsnd err\n");
			exit(1);
		}
		break;
	}

	return param;
}

int main(void)
{
	int status;
	pthread_t test;

	struct msgbuf message;
	struct msgbuf reply;

	printf("parent pid=%d\n", getpid() );
	

	/* set message */
	message.type = getpid();
	message.data.id = 1;
	strncpy( message.data.com, "command1", BUFSIZE );

	/* get message queue */
	msgkey = 1111;
	if( (msgQID_com = msgget( msgkey, 0666|IPC_CREAT) ) == -1 ){
		printf("msgget err\n");
		exit(1);
	}
	msgkey = 2222;
	if( (msgQID_res = msgget( msgkey, 0666|IPC_CREAT) ) == -1 ){
		printf("msgget err\n");
		exit(1);
	}


	/* create thread */
	status = pthread_create( &test, NULL, test_thread, NULL );
	if( status != 0 ){
		printf("thread create err\n");
		exit(1);
	}

	/* message send */
	if( msgsnd(msgQID_com, &message, sizeof(message.data), 0) == -1 ){
		printf("msgsnd err\n");
		exit(1);
	}

	/* rcv resp */
	if( msgrcv(msgQID_res, &reply, sizeof(reply.data), 0, 0) == -1 ){
		printf("msgrcv err\n");
		exit(1);
	}
	printf("reply data: id=%d data=%s\n", reply.data.id, reply.data.com);


	/* join thread */
 	status = pthread_join( test, NULL );
	if( status != 0 ){
		printf("thread join err\n");
		exit(1);
	}

	return 0;
}

ビルドする際には、

gcc -Wall pthread_test.c -lpthread

カテゴリ: [日記] - &trackback() - 2015年10月18日 00:09:13

#blognavi