ardupilot/libraries/SITL/SIM_SerialDevice.cpp

/*
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
/*
  base class for serially-attached simulated devices
*/

#include "SIM_SerialDevice.h"
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>

using namespace SITL;

SerialDevice::SerialDevice()
{
    int tmp[2];
    if (pipe(tmp) == -1) {
        AP_HAL::panic("pipe() failed");
    }
    fd_my_end    = tmp[1];
    fd_their_end = tmp[0];

    // close file descriptors on exec:
    fcntl(fd_my_end, F_SETFD, FD_CLOEXEC);
    fcntl(fd_their_end, F_SETFD, FD_CLOEXEC);

    // make sure we don't screw the simulation up by blocking:
    fcntl(fd_my_end, F_SETFL, fcntl(fd_my_end, F_GETFL, 0) | O_NONBLOCK);
    fcntl(fd_their_end, F_SETFL, fcntl(fd_their_end, F_GETFL, 0) | O_NONBLOCK);
}

bool SerialDevice::init_sitl_pointer()
{
    if (_sitl == nullptr) {
        _sitl = AP::sitl();
        if (_sitl == nullptr) {
            return false;
        }
    }
    return true;
}