linux 进程间的各种通信机制

android

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linux

1、信号

signal()函数：

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <linux/sched.h>
/*
	signal() ---->
		//linux/kernel/signal.c
		SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler)---->
			do_sigaction();--->
	
*/


void signal_handler(int signum)
{
	printf("signum=%d\n",signum);
}

int main(void)
{
	signal(16, signal_handler);
	
	while(1)
		sleep(5);
		
	return 0;
}

发送信号：kill -s 16  pid

2、消息队列

（进程1）发送消息

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

#include "def.h"

int main(void)
{
	int qid;
	key_t key;
	int ret;
	struct msgmbuf msg;
	
	//利用ftok产生标准的key
	key = ftok(KEY_ID,PROJ_ID);
	if (key == -1){
		printf("ftok err!\n");
		return -1;
	}
	printf("key:%d\n",key);
	
	//创建打开一个消息队列
	qid = msgget(key,IPC_CREAT|0777);
	if (qid == -1){
		printf("msgget err!\n");
		return -1;
	}
	printf("qid:%d\n",qid);
	
	msg.msg_type = getpid();
	//memcpy(msg.msg_buf,"ni hao hhhhhhhhh",strlen("ni hao hhhhhhhhh"));
	printf("pid:%ld", msg.msg_type);
	
	while (1)
	{
		printf("send.....\n");
		
		//发送消息
		ret = msgsnd(qid, &msg, sizeof(struct msgmbuf), 0);
		if (ret < 0){
			printf("msgsnd err!\n");
			return -1;
		}
		sleep(1);
	}
	
	/*
	//删除消息队列
	ret = msgctl(qid, IPC_RMID,NULL);
	if (ret < 0){
		printf("msgctl err!\n");
		return -1;
	}
	*/
	return 0;
}

进程2（接收消息）

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

#include "def.h"

int main(void)
{
	int qid;
	key_t key;
	int ret;
	struct msgmbuf msg;
	
	//利用ftok产生标准的key
	key = ftok(KEY_ID,PROJ_ID);
	if (key == -1){
		printf("ftok err!\n");
		return -1;
	}
	printf("key:%d\n",key);
	
	//创建打开一个消息队列
	qid = msgget(key,IPC_CREAT|0777);
	if (qid == -1){
		printf("msgget err!\n");
		return -1;
	}
	printf("qid:%d\n",qid);
	
	while (1)
	{
		//接收消息
		ret = msgrcv(qid, &msg, sizeof(struct msgmbuf),0, 0);
		if (ret < 0){
			printf("msgrcv err!\n");
			return -1;
		}

		printf("msgrcv:ret:%d,pid:%ld\n", ret,msg.msg_type);
	}
	
	/*
	//删除消息队列
	ret = msgctl(qid, IPC_RMID,NULL);
	if (ret < 0){
		printf("msgctl err!\n");
		return -1;
	}
	*/
	return 0;
}

公共头文件

#ifndef __DEF_H__
#define __DEF_H__

#define KEY_ID "/home/"
#define PROJ_ID 'A'

struct msgmbuf{
	long msg_type;
	char msg_buf[512];
};

#endif