[C++知识库]C++多线程实例（信号量）

#include <list>
#include <cstdio>
#include<cstdlib>
#include<unistd.h>
#include <exception>
#include <pthread.h>
#include<iostream>
#include<string>
#define num 3

using namespace std;
pthread_mutex_t lock;
volatile int XHL;
struct info{
	int id;
	string  info;
};
void* fun(void* arg)
{
	while(1)
	{
	XHL--;
	if(XHL>0)
	{
//	pthread_mutex_lock(&lock);
	auto i=(struct info*)arg;
	sleep(3);
	cout<<"thread_id:"<<i->id<<i->info<<endl;
//	pthread_mutex_unlock(&lock);
	XHL++;
	
//	pthread_exit(nullptr);
	}
	}
}
int main(){
	pthread_mutex_init(&lock,nullptr);
	int a=2;
	XHL=1;
	pthread_t tid[num];
	info t[num];
	for(int i=0;i<num;i++)
	{
		cout<<"creat"<<endl;
		t[i].id=i;
		t[i].info="info";

		int flag=pthread_create(&tid[i],nullptr,fun,(void*)&t[i]);
		cout<<"pthread_self"<<pthread_self<<endl;
		if(flag==-1)
			cout<<"pthreat_creat error"<<endl;
	}
	for(int i=0;i<num;i++)
	{
		cout<<"main_thread"<<endl;
	}
	pthread_detach(tid[0]);
	pthread_detach(tid[1]);
	pthread_detach(tid[2]);

/*	void* status;
	for(int i=0;i<num;i++)
	{
		bool flag=pthread_join(tid[i],&status);
		if(flag==1)
			cout<<"join error"<<endl;
		cout<<"exit status:"<<status<<endl;
	}*/
	pthread_exit(nullptr);
	return -1;
}