#if defined(OS_LINUX) #include #include #include #include #include #include namespace DB { namespace ErrorCodes { extern const int CANNOT_CREATE_TIMER; extern const int CANNOT_SET_TIMER_PERIOD; extern const int CANNOT_FCNTL; extern const int CANNOT_READ_FROM_SOCKET; } TimerDescriptor::TimerDescriptor(int clockid, int flags) { timer_fd = timerfd_create(clockid, flags); if (timer_fd == -1) throw Exception(ErrorCodes::CANNOT_CREATE_TIMER, "Cannot create timer_fd descriptor"); if (-1 == fcntl(timer_fd, F_SETFL, O_NONBLOCK)) throwFromErrno("Cannot set O_NONBLOCK for timer_fd", ErrorCodes::CANNOT_FCNTL); } TimerDescriptor::TimerDescriptor(TimerDescriptor && other) noexcept : timer_fd(other.timer_fd) { other.timer_fd = -1; } TimerDescriptor::~TimerDescriptor() { /// Do not check for result cause cannot throw exception. if (timer_fd != -1) { int err = close(timer_fd); chassert(!err || errno == EINTR); } } void TimerDescriptor::reset() const { itimerspec spec; spec.it_interval.tv_nsec = 0; spec.it_interval.tv_sec = 0; spec.it_value.tv_sec = 0; spec.it_value.tv_nsec = 0; if (-1 == timerfd_settime(timer_fd, 0 /*relative timer */, &spec, nullptr)) throwFromErrno("Cannot reset timer_fd", ErrorCodes::CANNOT_SET_TIMER_PERIOD); /// Drain socket. /// It may be possible that alarm happened and socket is readable. drain(); } void TimerDescriptor::drain() const { /// It is expected that socket returns 8 bytes when readable. /// Read in loop anyway cause signal may interrupt read call. uint64_t buf; while (true) { ssize_t res = ::read(timer_fd, &buf, sizeof(buf)); if (res < 0) { if (errno == EAGAIN) break; if (errno != EINTR) throwFromErrno("Cannot drain timer_fd", ErrorCodes::CANNOT_READ_FROM_SOCKET); } } } void TimerDescriptor::setRelative(uint64_t usec) const { static constexpr uint32_t TIMER_PRECISION = 1e6; itimerspec spec; spec.it_interval.tv_nsec = 0; spec.it_interval.tv_sec = 0; spec.it_value.tv_sec = usec / TIMER_PRECISION; spec.it_value.tv_nsec = (usec % TIMER_PRECISION) * 1'000; if (-1 == timerfd_settime(timer_fd, 0 /*relative timer */, &spec, nullptr)) throwFromErrno("Cannot set time for timer_fd", ErrorCodes::CANNOT_SET_TIMER_PERIOD); } void TimerDescriptor::setRelative(Poco::Timespan timespan) const { setRelative(timespan.totalMicroseconds()); } } #endif