get error pure virtual method called terminate called without an active exception when use I thread

[isan]

I want to use thread in my Client program to run functions together but I get this error pure virtual method called terminate called without an active exception and the program stops,why?

  bool setup::conn() {

	struct sockaddr_in serv_addr;
	struct hostent *server;

	sock = socket(AF_INET, SOCK_STREAM, 0);
	if (sock == -1){
		printf("ERROR opening socket");
		fflush(stdout);
	}

	server = gethostbyname("192.168.1.113");
	if (server <= 0) {
		fprintf(stderr, "ERROR, no such host\n");
		fflush(stdout);
	}
	bzero((char *) &serv_addr, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
	bcopy((char *) server->h_addr,
	(char *)&serv_addr.sin_addr.s_addr,
	server->h_length);
	serv_addr.sin_port = htons(MYPORT);

	while (true) {
		fflush(stdout);
		csock = (int*) malloc(sizeof(int));
		*csock = connect(sock, (struct sockaddr *) &serv_addr,
				sizeof(serv_addr));
		if (*csock == -1) {
			perror("error");
			if (errno == EISCONN  )
				break;
			

		}

		thread thread1;
		thread1 = thread(&setup::SocketHandler, this);
		 thread1.join();
     }
}
void setup::SocketHandler() {

	while (1) {

		if ((bytecount = recv(*csock, buffer, buffer_len, 0)) == -1)
			fprintf(stderr, "Error receiving data %d\n", errno);

		if (bytecount > 0) {
			printf("\n Received bytes: %d ", bytecount);
			
		}
                fflush(stdout);
		usleep(100);

	}
	pthread_exit(0);

}

[kbw]

You've not shown the declarations of the variables used. Without the types ...

Why are you allocating memory for the client socket? Why not just use an int?

[helios]

Is setup::conn() being called from setup's constructor? If setup::SocketHandler() is a virtual function then that's going to fail; you can't make virtual calls into this from the constructor.

[isan]

this is my setup.h

#include <time.h>
#include <fcntl.h>
#include <errno.h>
#include <resolv.h>
#include <thread>
....

#define MAXTIMINGS 85
#define MYPORT 3333
using namespace std;
class setup {
public:
	setup();
	void SocketHandler();
	void closeSocket();
	void set();
	bool conn();
	virtual ~setup();

	char buffer[1024];
	int buffer_len = 1024;
	int bytecount, bytecnt;
	int* csock;
        ....

};

#endif  

I do this but I get previous error again

setup s1;
std::thread t1 (&setup::SocketHandler, &s1);
 t1.join();

[kbw]

std::thread will takes a function and its arguments. But you're passing is a class method that takes no parameters.

When SocketHandler() runs, it's really doing this:

void setup::SocketHandler() {
	while (1) {
		if ((this->bytecount = recv(*this->csock, this->buffer, this->buffer_len, 0)) == -1)
			fprintf(stderr, "Error receiving data %d\n", errno);

		if (this->bytecount > 0) {
			printf("\n Received bytes: %d ", bytecount);
			
		}
                fflush(stdout);
		usleep(100);
	}
	pthread_exit(0);
}

And this is uninitialised.

Conceptually, you wouldn't run one member method in a different thread. You've have to specifically choose such a method and then design it to be run that way. You haven't done any of that. The whole thing's a mess

[helios]

std::thread will takes a function and its arguments. But you're passing is a class method that takes no parameters.

Doesn't the std::thread constructor understand member function pointers? I believe std::bind() will also accept binding this with the same syntax.

isan:

Is setup::conn() being called from setup's constructor? If setup::SocketHandler() is a virtual function then that's going to fail; you can't make virtual calls into this from the constructor.