pink-0

/*
        ##########    Copyright (C) 2016 Vincenzo Pacella
        ##      ##    Distributed under MIT license, see file LICENSE
        ##      ##    or <http://opensource.org/licenses/MIT>
        ##      ##
##########      #############################################################
shaduzlabs.com #####*/

#include <memory>
#include <tuple>

#ifdef __linux__

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <syslog.h>
#include <unistd.h>

#endif // __linux__

#include "Audio.h"
#include "Pink.h"

#include "ui/UserInterfaceNone.h"
#ifdef UI_USE_WEBSOCKET
#include "ui/UserInterfaceWebSocket.h"
#endif
#ifdef UI_USE_RASPBERRY_PI_ZERO
#include "ui/UserInterfacePiZero.h"
#endif

#define DAEMON_NAME "pinkd"

//--------------------------------------------------------------------------------------------------

#ifdef __linux__

int pidFilehandle;

#endif // __linux__

//--------------------------------------------------------------------------------------------------

#ifdef __linux__

void daemonShutdown()
{
  close(pidFilehandle);
}

#endif // __linux__

//--------------------------------------------------------------------------------------------------

#ifdef __linux__

void signalHandler(int sig)
{
  switch (sig)
  {
    case SIGHUP:
      syslog(LOG_WARNING, "Received SIGHUP signal.");
      break;
    case SIGINT:
    case SIGTERM:
      syslog(LOG_INFO, "Daemon exiting");
      daemonShutdown();
      exit(EXIT_SUCCESS);
      break;
    default:
      syslog(LOG_WARNING, "Unhandled signal %s", strsignal(sig));
      break;
  }
}

#endif // __linux__

//--------------------------------------------------------------------------------------------------

static void daemonize(const char* runDir_, const char* pidFile_)
{
#ifndef __linux__
  std::ignore = runDir_;
  std::ignore = pidFile_;
#else
  /* Our process ID and Session ID */
  pid_t pid, sid;
  int i;
  char str[10];
  struct sigaction newSigAction;
  sigset_t newSigSet;

  /* Check if parent process id is set */
  if (getppid() == 1)
  {
    /* PPID exists, therefore we are already a daemon */
    return;
  }

  sigemptyset(&newSigSet);
  sigaddset(&newSigSet, SIGCHLD);           /* ignore child - i.e. we don't need to wait for it */
  sigaddset(&newSigSet, SIGTSTP);           /* ignore Tty stop signals */
  sigaddset(&newSigSet, SIGTTOU);           /* ignore Tty background writes */
  sigaddset(&newSigSet, SIGTTIN);           /* ignore Tty background reads */
  sigprocmask(SIG_BLOCK, &newSigSet, NULL); /* Block the above specified signals */

  /* Set up a signal handler */
  newSigAction.sa_handler = signalHandler;
  sigemptyset(&newSigAction.sa_mask);
  newSigAction.sa_flags = 0;

  /* Signals to handle */
  sigaction(SIGHUP, &newSigAction, NULL);  /* catch hangup signal */
  sigaction(SIGTERM, &newSigAction, NULL); /* catch term signal */
  sigaction(SIGINT, &newSigAction, NULL);  /* catch interrupt signal */

  /* Fork off the parent process */
  pid = fork();
  if (pid < 0)
  {
    exit(EXIT_FAILURE);
  }
  /* If we got a good PID, then we can exit the parent process. */
  if (pid > 0)
  {
    exit(EXIT_SUCCESS);
  }

  /* Change the file mode mask */
  umask(027);

  /* Create a new SID for the child process */
  sid = setsid();
  if (sid < 0)
  {
    /* Log the failure */
    syslog(LOG_ERR, "ERROR: Failed to create a new session");
    exit(EXIT_FAILURE);
  }

  /* Close out the open file descriptors */
  for (int fd = sysconf(_SC_OPEN_MAX); fd > 0; fd--)
  {
    close(fd);
  }

  /* Route I/O connections */

  /* Open STDIN */
  i = open("/dev/null", O_RDWR);

  /* STDOUT */
  dup(i);

  /* STDERR */
  dup(i);

  if ((chdir(runDir_)) < 0)
  {
    syslog(LOG_ERR, "ERROR: Failed to change the working directory to %s", runDir_);
    exit(EXIT_FAILURE);
  }

  /* Ensure only one copy */
  pidFilehandle = open(pidFile_, O_RDWR | O_CREAT, 0600);

  if (pidFilehandle == -1)
  {
    /* Couldn't open lock file */
    syslog(LOG_INFO, "Could not open PID lock file %s, exiting", pidFile_);
    exit(EXIT_FAILURE);
  }

  /* Try to lock file */
  if (lockf(pidFilehandle, F_TLOCK, 0) == -1)
  {
    /* Couldn't get lock on lock file */
    syslog(LOG_INFO, "Could not lock PID lock file %s, exiting", pidFile_);
    exit(EXIT_FAILURE);
  }

  /* Get and format PID */
  sprintf(str, "%d\n", getpid());

  /* write pid to lockfile */
  write(pidFilehandle, str, strlen(str));
#endif
}

//--------------------------------------------------------------------------------------------------

class ScopedLog
{
public:
  ScopedLog()
  {
#ifdef __linux__
    setlogmask(LOG_UPTO(LOG_INFO));
    openlog(DAEMON_NAME, LOG_CONS | LOG_PERROR, LOG_USER);
#endif // __linux__
  }
  ~ScopedLog()
  {
#ifdef __linux__
    closelog();
#endif // __linux__
  }

  void info(const char* message_)
  {
#ifdef __linux__
    syslog(LOG_INFO, message_);
#else
    std::cout << DAEMON_NAME << ": " << message_ << std::endl;
#endif
  }

  void exception(const std::exception& e_)
  {
#ifdef __linux__
    syslog(LOG_ERR, "ERROR: An exception occurred  (%s)", e_.what());
#else
    std::cerr << "An exception occurred: " << e_.what() << std::endl;
#endif
  }
};

//--------------------------------------------------------------------------------------------------

using namespace sl;
using namespace sl::pi;

int main(int argc_, char* argv_[])
{
  ScopedLog log;

  log.info("daemon starting");
  if (argc_ != 2 || std::string(argv_[1]) != "no-daemon")
  {
    daemonize("/tmp/", "/var/run/pinkd.pid");
  }

  std::shared_ptr<Pink> pink(new Pink(120., 4., 1.0));

#ifdef UI_USE_WEBSOCKET
  UserInterfaceWebSocket webSocket(pink);
#endif
#ifdef UI_USE_RASPBERRY_PI_ZERO
  UserInterfacePiZero zero(pink);
#endif
#if !defined(UI_USE_RASPBERRY_PI_ZERO) && !defined(UI_USE_WEBSOCKET)
  UserInterfaceNone zero(pink);
#endif

  log.info("daemon running");

  try
  {
    while (true)
    {
      std::this_thread::sleep_for(std::chrono::milliseconds(10));
    }
  }
  catch (const std::exception& e)
  {
    log.exception(e);
  }

  log.info("daemon terminated");

  return 0;
}

//--------------------------------------------------------------------------------------------------