examples/poll.cpp

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/*****************************************************************************
** Includes
*****************************************************************************/

#include <iostream>
#include <cstdlib>
#include <ecl/config/ecl.hpp>
#include <ecl/errors/handlers.hpp>
#include "../../include/ecl/io/poll.hpp"
#include "../../include/ecl/io/socketpair.hpp"
#ifndef ECL_IS_WIN32
  #include <unistd.h>
#endif

/*****************************************************************************
** Macros
*****************************************************************************/

#define DATA1 "In Xanadu, did Kublai Khan . . ."
#define DATA2 "A stately pleasure dome decree . . ."

/*****************************************************************************
** Globals
*****************************************************************************/

ecl::socket_descriptor socket_pair[2];

/*****************************************************************************
** Functions
*****************************************************************************/

int socket_error() {
#ifdef ECL_IS_WIN32
        return WSAGetLastError();
#else
        return errno;
#endif
}

void sleep_one_sec() {
#ifdef ECL_IS_WIN32
        Sleep(1000);
#else
        sleep(1);
#endif
}

/*****************************************************************************
** Main
*****************************************************************************/

int main(int argc, char **argv) {

        ecl::SocketError error = ecl::init_sockets();
        if ( error.flag() != ecl::NoError ) {
                std::cout << error.what() << std::endl;
                abort();
        }

        // non blocking mode - need it so the read's don't block below.
        error = ecl::socketpair(socket_pair,true);

        if ( error.flag() != ecl::NoError) {
                std::cout << error.what() << std::endl;
                std::cout << "SocketPair Error: " << socket_error() << std::endl;
                abort();
        }
        ecl::socket_pollfd pfd[2];
        pfd[0].fd = socket_pair[0];
        pfd[0].events = POLLIN;
        pfd[0].revents = 0;
        pfd[1].fd = socket_pair[1];
        pfd[1].events = POLLIN;
        pfd[1].revents = 0;

        int poll_timeout = 500; // ms
        int result = 0;
        unsigned int count = 0;
        while ( count < 10 ) {
                if((result = ecl::poll_sockets(pfd, 2, poll_timeout)) < 0) {
                        std::cout << socket_error();
                } else if ( result > 0 ) {
                        char receiving_buffer[256];
                        int n;
                        for ( unsigned int i = 0; i < 2; ++i ) {
                                if ( pfd[i].revents == POLLIN ) {
#ifdef ECL_IS_WIN32
                                        while ( ( n = ::recv(socket_pair[i], reinterpret_cast<char*>(receiving_buffer), 256, 0) ) > 0 ) {
#else
                                        while( (n = read(socket_pair[i], receiving_buffer, 256)) > 0) {
#endif
                                                std::cout << receiving_buffer << std::endl;
                                                if ( i == 0 ) {
#ifdef ECL_IS_WIN32
                                                        if( ::send(socket_pair[0], reinterpret_cast<const char*>(DATA1), sizeof(DATA1), 0) < 0 ) {
#else
                                                        if (write(socket_pair[0], DATA1, sizeof(DATA1)) < 0) {
#endif
                                                                std::cerr << "Failed to write to the socket." << std::endl;
                                                        }
                                                } else {
#ifdef ECL_IS_WIN32
                                                        if( ::send(socket_pair[1], reinterpret_cast<const char*>(DATA2), sizeof(DATA2), 0) < 0 ) {
#else
                                                        if (write(socket_pair[1], DATA2, sizeof(DATA2)) < 0) {
#endif
                                                                std::cerr << "Failed to write to the socket." << std::endl;
                                                        }
                                                }
                                        };
                                        pfd[i].revents = 0;
                                }
                        }
                        sleep_one_sec();
                } else {
                        // it will pass through here once to kickstart things
#ifdef ECL_IS_WIN32
                        if( ::send(socket_pair[0], reinterpret_cast<const char*>(DATA1), sizeof(DATA1), 0) < 0 ) {
#else
                        if (write(socket_pair[0], DATA1, sizeof(DATA1)) < 0) {
#endif
                                std::cerr << "Failed to write to the socket." << std::endl;
                        }
                        sleep_one_sec();
                }
                ++count;
        }


        ecl::close_socket(socket_pair[0]);
        ecl::close_socket(socket_pair[1]);

        return 0;
}