// Copyright 2010 Google Inc.
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#include "utils/signals/misc.hpp"

#if defined(HAVE_CONFIG_H)
#   include "config.h"
#endif

extern "C" {
#include <signal.h>
}

#include <cerrno>
#include <cstddef>

#include "utils/format/macros.hpp"
#include "utils/signals/exceptions.hpp"

namespace signals = utils::signals;


/// Number of the last valid signal.
const int utils::signals::last_signo = LAST_SIGNO;


/// Resets a signal handler to its default behavior.
///
/// \param signo The number of the signal handler to reset.
///
/// \throw signals::system_error If there is a problem trying to reset the
///     signal handler to its default behavior.
void
signals::reset(const int signo)
{
    struct ::sigaction sa;
    sa.sa_handler = SIG_DFL;
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = 0;

    if (::sigaction(signo, &sa, NULL) == -1) {
        const int original_errno = errno;
        throw system_error(F("Failed to reset signal %s") % signo,
                           original_errno);
    }
}