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#include <QSocketNotifier>
#include <signal.h>
#include <sys/socket.h>
#include <unistd.h>
#include "unixsignalhandler.h"

int UnixSignalHandler::sigintFd[2] = {0};
int UnixSignalHandler::sighupFd[2] = {0};
int UnixSignalHandler::sigtermFd[2] = {0};

UnixSignalHandler::UnixSignalHandler(QObject *parent)
    : QObject(parent)
{
    if (::socketpair(AF_UNIX, SOCK_STREAM, 0, sigintFd))
       qFatal("Couldn't create INT socketpair");

    if (::socketpair(AF_UNIX, SOCK_STREAM, 0, sighupFd))
       qFatal("Couldn't create HUP socketpair");

    if (::socketpair(AF_UNIX, SOCK_STREAM, 0, sigtermFd))
       qFatal("Couldn't create TERM socketpair");

    m_sigintNotifier = new QSocketNotifier(sigintFd[1], QSocketNotifier::Read, this);
    connect(m_sigintNotifier, &QSocketNotifier::activated,
            this, &UnixSignalHandler::handleSigInt);
    m_sighupNotifier = new QSocketNotifier(sighupFd[1], QSocketNotifier::Read, this);
    connect(m_sighupNotifier, &QSocketNotifier::activated,
            this, &UnixSignalHandler::handleSigHup);
    m_sigtermNotifier = new QSocketNotifier(sigtermFd[1], QSocketNotifier::Read, this);
    connect(m_sigtermNotifier, &QSocketNotifier::activated,
            this, &UnixSignalHandler::handleSigTerm);
}

int UnixSignalHandler::setupSignalHandlers()
{
    struct sigaction sig_int, sig_hup, sig_term;

    sig_int.sa_handler = UnixSignalHandler::sigIntHandler;
    sigemptyset(&sig_int.sa_mask);
    sig_int.sa_flags = 0;
    sig_int.sa_flags |= SA_RESTART;

    if (sigaction(SIGINT, &sig_int, 0))
       return 1;

    sig_hup.sa_handler = UnixSignalHandler::sigHupHandler;
    sigemptyset(&sig_hup.sa_mask);
    sig_hup.sa_flags = 0;
    sig_hup.sa_flags |= SA_RESTART;

    if (sigaction(SIGHUP, &sig_hup, 0))
       return 2;

    sig_term.sa_handler = UnixSignalHandler::sigTermHandler;
    sigemptyset(&sig_term.sa_mask);
    sig_term.sa_flags |= SA_RESTART;

    if (sigaction(SIGTERM, &sig_term, 0))
       return 3;

    return 0;
}

void UnixSignalHandler::sigIntHandler(int)
{
    char a = 1;
    ::write(sigintFd[0], &a, sizeof(a));
}

void UnixSignalHandler::sigHupHandler(int)
{
    char a = 1;
    ::write(sighupFd[0], &a, sizeof(a));
}

void UnixSignalHandler::sigTermHandler(int)
{
    char a = 1;
    ::write(sigtermFd[0], &a, sizeof(a));
}

void UnixSignalHandler::handleSigInt()
{
    m_sigintNotifier->setEnabled(false);
    char tmp;
    ::read(sigintFd[1], &tmp, sizeof(tmp));

    emit sigInt();

    m_sigintNotifier->setEnabled(true);
}

void UnixSignalHandler::handleSigHup()
{
    m_sighupNotifier->setEnabled(false);
    char tmp;
    ::read(sighupFd[1], &tmp, sizeof(tmp));

    emit sigHup();

    m_sighupNotifier->setEnabled(true);
}

void UnixSignalHandler::handleSigTerm()
{
    m_sigtermNotifier->setEnabled(false);
    char tmp;
    ::read(sigtermFd[1], &tmp, sizeof(tmp));

    emit sigTerm();

    m_sigtermNotifier->setEnabled(true);
}