text: /* select - Module containing unix select(2) call.
     Under Unix, the file descriptors are small integers.
     Under Win32, select only exists for sockets, and sockets may
     have any value except INVALID_SOCKET.
  */
  
  #include "Python.h"
  #include <structmember.h>
  
  #ifdef HAVE_SYS_DEVPOLL_H
  #include <sys/resource.h>
  #include <sys/devpoll.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #endif
  
  #ifdef __APPLE__
      /* Perform runtime testing for a broken poll on OSX to make it easier
       * to use the same binary on multiple releases of the OS.
       */
  #undef HAVE_BROKEN_POLL
  #endif
  
  /* Windows #defines FD_SETSIZE to 64 if FD_SETSIZE isn't already defined.
     64 is too small (too many people have bumped into that limit).
     Here we boost it.
     Users who want even more than the boosted limit should #define
     FD_SETSIZE higher before this; e.g., via compiler /D switch.
  */
  #if defined(MS_WINDOWS) && !defined(FD_SETSIZE)
  #define FD_SETSIZE 512
  #endif
  
  #if defined(HAVE_POLL_H)
  #include <poll.h>
  #elif defined(HAVE_SYS_POLL_H)
  #include <sys/poll.h>
  #endif
  
  #ifdef __sgi
  /* This is missing from unistd.h */
  extern void bzero(void *, int);
  #endif
  
  #ifdef HAVE_SYS_TYPES_H
  #include <sys/types.h>
  #endif
  
  #ifdef MS_WINDOWS
  #  define WIN32_LEAN_AND_MEAN
  #  include <winsock.h>
  #else
  #  define SOCKET int
  #endif
  
  /* list of Python objects and their file descriptor */
  typedef struct {
      PyObject *obj;                           /* owned reference */
      SOCKET fd;
      int sentinel;                            /* -1 == sentinel */
  } pylist;
  
  static void
  reap_obj(pylist fd2obj[FD_SETSIZE + 1])
  {
      int i;
      for (i = 0; i < FD_SETSIZE + 1 && fd2obj[i].sentinel >= 0; i++) {
          Py_CLEAR(fd2obj[i].obj);
      }
      fd2obj[0].sentinel = -1;
  }
  
  
  /* returns -1 and sets the Python exception if an error occurred, otherwise
     returns a number >= 0
  */
  static int
  seq2set(PyObject *seq, fd_set *set, pylist fd2obj[FD_SETSIZE + 1])
  {
      int max = -1;
      int index = 0;
      Py_ssize_t i;
      PyObject* fast_seq = NULL;
      PyObject* o = NULL;
  
      fd2obj[0].obj = (PyObject*)0;            /* set list to zero size */
      FD_ZERO(set);
  
      fast_seq = PySequence_Fast(seq, "arguments 1-3 must be sequences");
      if (!fast_seq)
          return -1;
  
      for (i = 0; i < PySequence_Fast_GET_SIZE(fast_seq); i++)  {
          SOCKET v;
  
          /* any intervening fileno() calls could decr this refcnt */
          if (!(o = PySequence_Fast_GET_ITEM(fast_seq, i)))
              goto finally;
  
          Py_INCREF(o);
          v = PyObject_AsFileDescriptor( o );
          if (v == -1) goto finally;
  
  #if defined(_MSC_VER)
          max = 0;                             /* not used for Win32 */
  #else  /* !_MSC_VER */
          if (!_PyIsSelectable_fd(v)) {
              PyErr_SetString(PyExc_ValueError,
                          "filedescriptor out of range in select()");
              goto finally;
          }
          if (v > max)
              max = v;
  #endif /* _MSC_VER */
          FD_SET(v, set);
  
          /* add object and its file descriptor to the list */
          if (index >= FD_SETSIZE) {
              PyErr_SetString(PyExc_ValueError,
                            "too many file descriptors in select()");
              goto finally;
          }
          fd2obj[index].obj = o;
          fd2obj[index].fd = v;
          fd2obj[index].sentinel = 0;
          fd2obj[++index].sentinel = -1;
      }
      Py_DECREF(fast_seq);
      return max+1;
  
    finally:
      Py_XDECREF(o);
      Py_DECREF(fast_seq);
      return -1;
  }
  
  /* returns NULL and sets the Python exception if an error occurred */
  static PyObject *
  set2list(fd_set *set, pylist fd2obj[FD_SETSIZE + 1])
  {
      int i, j, count=0;
      PyObject *list, *o;
      SOCKET fd;
  
      for (j = 0; fd2obj[j].sentinel >= 0; j++) {
          if (FD_ISSET(fd2obj[j].fd, set))
              count++;
      }
      list = PyList_New(count);
      if (!list)
          return NULL;
  
      i = 0;
      for (j = 0; fd2obj[j].sentinel >= 0; j++) {
          fd = fd2obj[j].fd;
          if (FD_ISSET(fd, set)) {
              o = fd2obj[j].obj;
              fd2obj[j].obj = NULL;
              /* transfer ownership */
              if (PyList_SetItem(list, i, o) < 0)
                  goto finally;
  
              i++;
          }
      }
      return list;
    finally:
      Py_DECREF(list);
      return NULL;
  }
  
  #undef SELECT_USES_HEAP
  #if FD_SETSIZE > 1024
  #define SELECT_USES_HEAP
  #endif /* FD_SETSIZE > 1024 */
  
  static PyObject *
  select_select(PyObject *self, PyObject *args)
  {
  #ifdef SELECT_USES_HEAP
      pylist *rfd2obj, *wfd2obj, *efd2obj;
  #else  /* !SELECT_USES_HEAP */
      /* XXX: All this should probably be implemented as follows:
       * - find the highest descriptor we're interested in
       * - add one
       * - that's the size
       * See: Stevens, APitUE, $12.5.1
       */
      pylist rfd2obj[FD_SETSIZE + 1];
      pylist wfd2obj[FD_SETSIZE + 1];
      pylist efd2obj[FD_SETSIZE + 1];
  #endif /* SELECT_USES_HEAP */
      PyObject *ifdlist, *ofdlist, *efdlist;
      PyObject *ret = NULL;
      PyObject *timeout_obj = Py_None;
      fd_set ifdset, ofdset, efdset;
      struct timeval tv, *tvp;
      int imax, omax, emax, max;
      int n;
      _PyTime_t timeout, deadline = 0;
  
      /* convert arguments */
      if (!PyArg_UnpackTuple(args, "select", 3, 4,
                            &ifdlist, &ofdlist, &efdlist, &timeout_obj))
          return NULL;
  
      if (timeout_obj == Py_None)
          tvp = (struct timeval *)NULL;
      else {
          if (_PyTime_FromSecondsObject(&timeout, timeout_obj,
                                        _PyTime_ROUND_CEILING) < 0) {
              if (PyErr_ExceptionMatches(PyExc_TypeError)) {
                  PyErr_SetString(PyExc_TypeError,
                                  "timeout must be a float or None");
              }
              return NULL;
          }
  
          if (_PyTime_AsTimeval(timeout, &tv, _PyTime_ROUND_CEILING) == -1)
              return NULL;
          if (tv.tv_sec < 0) {
              PyErr_SetString(PyExc_ValueError, "timeout must be non-negative");
              return NULL;
          }
          tvp = &tv;
      }
  
  #ifdef SELECT_USES_HEAP
      /* Allocate memory for the lists */
      rfd2obj = PyMem_NEW(pylist, FD_SETSIZE + 1);
      wfd2obj = PyMem_NEW(pylist, FD_SETSIZE + 1);
      efd2obj = PyMem_NEW(pylist, FD_SETSIZE + 1);
      if (rfd2obj == NULL || wfd2obj == NULL || efd2obj == NULL) {
          if (rfd2obj) PyMem_DEL(rfd2obj);
          if (wfd2obj) PyMem_DEL(wfd2obj);
          if (efd2obj) PyMem_DEL(efd2obj);
          return PyErr_NoMemory();
      }
  #endif /* SELECT_USES_HEAP */
  
      /* Convert sequences to fd_sets, and get maximum fd number
       * propagates the Python exception set in seq2set()
       */
      rfd2obj[0].sentinel = -1;
      wfd2obj[0].sentinel = -1;
      efd2obj[0].sentinel = -1;
      if ((imax=seq2set(ifdlist, &ifdset, rfd2obj)) < 0)
          goto finally;
      if ((omax=seq2set(ofdlist, &ofdset, wfd2obj)) < 0)
          goto finally;
      if ((emax=seq2set(efdlist, &efdset, efd2obj)) < 0)
          goto finally;
  
      max = imax;
      if (omax > max) max = omax;
      if (emax > max) max = emax;
  
      if (tvp)
          deadline = _PyTime_GetMonotonicClock() + timeout;
  
      do {
          Py_BEGIN_ALLOW_THREADS
          errno = 0;
          n = select(max, &ifdset, &ofdset, &efdset, tvp);
          Py_END_ALLOW_THREADS
  
          if (errno != EINTR)
              break;
  
          /* select() was interrupted by a signal */
          if (PyErr_CheckSignals())
              goto finally;
  
          if (tvp) {
              timeout = deadline - _PyTime_GetMonotonicClock();
              if (timeout < 0) {
                  n = 0;
                  break;
              }
              _PyTime_AsTimeval_noraise(timeout, &tv, _PyTime_ROUND_CEILING);
              /* retry select() with the recomputed timeout */
          }
      } while (1);
  
  #ifdef MS_WINDOWS
      if (n == SOCKET_ERROR) {
          PyErr_SetExcFromWindowsErr(PyExc_OSError, WSAGetLastError());
      }
  #else
      if (n < 0) {
          PyErr_SetFromErrno(PyExc_OSError);
      }
  #endif
      else {
          /* any of these three calls can raise an exception.  it's more
             convenient to test for this after all three calls... but
             is that acceptable?
          */
          ifdlist = set2list(&ifdset, rfd2obj);
          ofdlist = set2list(&ofdset, wfd2obj);
          efdlist = set2list(&efdset, efd2obj);
          if (PyErr_Occurred())
              ret = NULL;
          else
              ret = PyTuple_Pack(3, ifdlist, ofdlist, efdlist);
  
          Py_XDECREF(ifdlist);
          Py_XDECREF(ofdlist);
          Py_XDECREF(efdlist);
      }
  
    finally:
      reap_obj(rfd2obj);
      reap_obj(wfd2obj);
      reap_obj(efd2obj);
  #ifdef SELECT_USES_HEAP
      PyMem_DEL(rfd2obj);
      PyMem_DEL(wfd2obj);
      PyMem_DEL(efd2obj);
  #endif /* SELECT_USES_HEAP */
      return ret;
  }
  
  #if defined(HAVE_POLL) && !defined(HAVE_BROKEN_POLL)
  /*
   * poll() support
   */
  
  typedef struct {
      PyObject_HEAD
      PyObject *dict;
      int ufd_uptodate;
      int ufd_len;
      struct pollfd *ufds;
      int poll_running;
  } pollObject;
  
  static PyTypeObject poll_Type;
  
  /* Update the malloc'ed array of pollfds to match the dictionary
     contained within a pollObject.  Return 1 on success, 0 on an error.
  */
  
  static int
  update_ufd_array(pollObject *self)
  {
      Py_ssize_t i, pos;
      PyObject *key, *value;
      struct pollfd *old_ufds = self->ufds;
  
      self->ufd_len = PyDict_Size(self->dict);
      PyMem_RESIZE(self->ufds, struct pollfd, self->ufd_len);
      if (self->ufds == NULL) {
          self->ufds = old_ufds;
          PyErr_NoMemory();
          return 0;
      }
  
      i = pos = 0;
      while (PyDict_Next(self->dict, &pos, &key, &value)) {
          assert(i < self->ufd_len);
          /* Never overflow */
          self->ufds[i].fd = (int)PyLong_AsLong(key);
          self->ufds[i].events = (short)(unsigned short)PyLong_AsLong(value);
          i++;
      }
      assert(i == self->ufd_len);
      self->ufd_uptodate = 1;
      return 1;
  }
  
  static int
  ushort_converter(PyObject *obj, void *ptr)
  {
      unsigned long uval;
  
      uval = PyLong_AsUnsignedLong(obj);
      if (uval == (unsigned long)-1 && PyErr_Occurred())
          return 0;
      if (uval > USHRT_MAX) {
          PyErr_SetString(PyExc_OverflowError,
                          "Python int too large for C unsigned short");
          return 0;
      }
  
      *(unsigned short *)ptr = Py_SAFE_DOWNCAST(uval, unsigned long, unsigned short);
      return 1;
  }
  
  PyDoc_STRVAR(poll_register_doc,
  "register(fd [, eventmask] ) -> None\n\n\
  Register a file descriptor with the polling object.\n\
  fd -- either an integer, or an object with a fileno() method returning an\n\
        int.\n\
  events -- an optional bitmask describing the type of events to check for");
  
  static PyObject *
  poll_register(pollObject *self, PyObject *args)
  {
      PyObject *o, *key, *value;
      int fd;
      unsigned short events = POLLIN | POLLPRI | POLLOUT;
      int err;
  
      if (!PyArg_ParseTuple(args, "O|O&:register", &o, ushort_converter, &events))
          return NULL;
  
      fd = PyObject_AsFileDescriptor(o);
      if (fd == -1) return NULL;
  
      /* Add entry to the internal dictionary: the key is the
         file descriptor, and the value is the event mask. */
      key = PyLong_FromLong(fd);
      if (key == NULL)
          return NULL;
      value = PyLong_FromLong(events);
      if (value == NULL) {
          Py_DECREF(key);
          return NULL;
      }
      err = PyDict_SetItem(self->dict, key, value);
      Py_DECREF(key);
      Py_DECREF(value);
      if (err < 0)
          return NULL;
  
      self->ufd_uptodate = 0;
  
      Py_INCREF(Py_None);
      return Py_None;
  }
  
  PyDoc_STRVAR(poll_modify_doc,
  "modify(fd, eventmask) -> None\n\n\
  Modify an already registered file descriptor.\n\
  fd -- either an integer, or an object with a fileno() method returning an\n\
        int.\n\
  events -- an optional bitmask describing the type of events to check for");
  
  static PyObject *
  poll_modify(pollObject *self, PyObject *args)
  {
      PyObject *o, *key, *value;
      int fd;
      unsigned short events;
      int err;
  
      if (!PyArg_ParseTuple(args, "OO&:modify", &o, ushort_converter, &events))
          return NULL;
  
      fd = PyObject_AsFileDescriptor(o);
      if (fd == -1) return NULL;
  
      /* Modify registered fd */
      key = PyLong_FromLong(fd);
      if (key == NULL)
          return NULL;
      if (PyDict_GetItem(self->dict, key) == NULL) {
          errno = ENOENT;
          PyErr_SetFromErrno(PyExc_OSError);
          Py_DECREF(key);
          return NULL;
      }
      value = PyLong_FromLong(events);
      if (value == NULL) {
          Py_DECREF(key);
          return NULL;
      }
      err = PyDict_SetItem(self->dict, key, value);
      Py_DECREF(key);
      Py_DECREF(value);
      if (err < 0)
          return NULL;
  
      self->ufd_uptodate = 0;
  
      Py_INCREF(Py_None);
      return Py_None;
  }
  
  
  PyDoc_STRVAR(poll_unregister_doc,
  "unregister(fd) -> None\n\n\
  Remove a file descriptor being tracked by the polling object.");
  
  static PyObject *
  poll_unregister(pollObject *self, PyObject *o)
  {
      PyObject *key;
      int fd;
  
      fd = PyObject_AsFileDescriptor( o );
      if (fd == -1)
          return NULL;
  
      /* Check whether the fd is already in the array */
      key = PyLong_FromLong(fd);
      if (key == NULL)
          return NULL;
  
      if (PyDict_DelItem(self->dict, key) == -1) {
          Py_DECREF(key);
          /* This will simply raise the KeyError set by PyDict_DelItem
             if the file descriptor isn't registered. */
          return NULL;
      }
  
      Py_DECREF(key);
      self->ufd_uptodate = 0;
  
      Py_INCREF(Py_None);
      return Py_None;
  }
  
  PyDoc_STRVAR(poll_poll_doc,
  "poll( [timeout] ) -> list of (fd, event) 2-tuples\n\n\
  Polls the set of registered file descriptors, returning a list containing \n\
  any descriptors that have events or errors to report.");
  
  static PyObject *
  poll_poll(pollObject *self, PyObject *args)
  {
      PyObject *result_list = NULL, *timeout_obj = NULL;
      int poll_result, i, j;
      PyObject *value = NULL, *num = NULL;
      _PyTime_t timeout, ms, deadline;
      int async_err = 0;
  
      if (!PyArg_ParseTuple(args, "|O:poll", &timeout_obj)) {
          return NULL;
      }
  
      /* Check values for timeout */
      if (timeout_obj == NULL || timeout_obj == Py_None) {
          timeout = -1;
          ms = -1;
          deadline = 0;   /* initialize to prevent gcc warning */
      }
      else {
          if (_PyTime_FromMillisecondsObject(&timeout, timeout_obj,
                                             _PyTime_ROUND_CEILING) < 0) {
              if (PyErr_ExceptionMatches(PyExc_TypeError)) {
                  PyErr_SetString(PyExc_TypeError,
                                  "timeout must be an integer or None");
              }
              return NULL;
          }
  
          ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
          if (ms < INT_MIN || ms > INT_MAX) {
              PyErr_SetString(PyExc_OverflowError, "timeout is too large");
              return NULL;
          }
  
          deadline = _PyTime_GetMonotonicClock() + timeout;
      }
  
      /* Avoid concurrent poll() invocation, issue 8865 */
      if (self->poll_running) {
          PyErr_SetString(PyExc_RuntimeError,
                          "concurrent poll() invocation");
          return NULL;
      }
  
      /* Ensure the ufd array is up to date */
      if (!self->ufd_uptodate)
          if (update_ufd_array(self) == 0)
              return NULL;
  
      self->poll_running = 1;
  
      /* call poll() */
      async_err = 0;
      do {
          Py_BEGIN_ALLOW_THREADS
          errno = 0;
          poll_result = poll(self->ufds, self->ufd_len, (int)ms);
          Py_END_ALLOW_THREADS
  
          if (errno != EINTR)
              break;
  
          /* poll() was interrupted by a signal */
          if (PyErr_CheckSignals()) {
              async_err = 1;
              break;
          }
  
          if (timeout >= 0) {
              timeout = deadline - _PyTime_GetMonotonicClock();
              if (timeout < 0) {
                  poll_result = 0;
                  break;
              }
              ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
              /* retry poll() with the recomputed timeout */
          }
      } while (1);
  
      self->poll_running = 0;
  
      if (poll_result < 0) {
          if (!async_err)
              PyErr_SetFromErrno(PyExc_OSError);
          return NULL;
      }
  
      /* build the result list */
  
      result_list = PyList_New(poll_result);
      if (!result_list)
          return NULL;
  
      for (i = 0, j = 0; j < poll_result; j++) {
          /* skip to the next fired descriptor */
          while (!self->ufds[i].revents) {
              i++;
          }
          /* if we hit a NULL return, set value to NULL
             and break out of loop; code at end will
             clean up result_list */
          value = PyTuple_New(2);
          if (value == NULL)
              goto error;
          num = PyLong_FromLong(self->ufds[i].fd);
          if (num == NULL) {
              Py_DECREF(value);
              goto error;
          }
          PyTuple_SET_ITEM(value, 0, num);
  
          /* The &0xffff is a workaround for AIX.  'revents'
             is a 16-bit short, and IBM assigned POLLNVAL
             to be 0x8000, so the conversion to int results
             in a negative number. See SF bug #923315. */
          num = PyLong_FromLong(self->ufds[i].revents & 0xffff);
          if (num == NULL) {
              Py_DECREF(value);
              goto error;
          }
          PyTuple_SET_ITEM(value, 1, num);
          if ((PyList_SetItem(result_list, j, value)) == -1) {
              Py_DECREF(value);
              goto error;
          }
          i++;
      }
      return result_list;
  
    error:
      Py_DECREF(result_list);
      return NULL;
  }
  
  static PyMethodDef poll_methods[] = {
      {"register",        (PyCFunction)poll_register,
       METH_VARARGS,  poll_register_doc},
      {"modify",          (PyCFunction)poll_modify,
       METH_VARARGS,  poll_modify_doc},
      {"unregister",      (PyCFunction)poll_unregister,
       METH_O,        poll_unregister_doc},
      {"poll",            (PyCFunction)poll_poll,
       METH_VARARGS,  poll_poll_doc},
      {NULL,              NULL}           /* sentinel */
  };
  
  static pollObject *
  newPollObject(void)
  {
      pollObject *self;
      self = PyObject_New(pollObject, &poll_Type);
      if (self == NULL)
          return NULL;
      /* ufd_uptodate is a Boolean, denoting whether the
         array pointed to by ufds matches the contents of the dictionary. */
      self->ufd_uptodate = 0;
      self->ufds = NULL;
      self->poll_running = 0;
      self->dict = PyDict_New();
      if (self->dict == NULL) {
          Py_DECREF(self);
          return NULL;
      }
      return self;
  }
  
  static void
  poll_dealloc(pollObject *self)
  {
      if (self->ufds != NULL)
          PyMem_DEL(self->ufds);
      Py_XDECREF(self->dict);
      PyObject_Del(self);
  }
  
  static PyTypeObject poll_Type = {
      /* The ob_type field must be initialized in the module init function
       * to be portable to Windows without using C++. */
      PyVarObject_HEAD_INIT(NULL, 0)
      "select.poll",              /*tp_name*/
      sizeof(pollObject),         /*tp_basicsize*/
      0,                          /*tp_itemsize*/
      /* methods */
      (destructor)poll_dealloc, /*tp_dealloc*/
      0,                          /*tp_print*/
      0,                          /*tp_getattr*/
      0,                      /*tp_setattr*/
      0,                          /*tp_reserved*/
      0,                          /*tp_repr*/
      0,                          /*tp_as_number*/
      0,                          /*tp_as_sequence*/
      0,                          /*tp_as_mapping*/
      0,                          /*tp_hash*/
      0,                          /*tp_call*/
      0,                          /*tp_str*/
      0,                          /*tp_getattro*/
      0,                          /*tp_setattro*/
      0,                          /*tp_as_buffer*/
      Py_TPFLAGS_DEFAULT,         /*tp_flags*/
      0,                          /*tp_doc*/
      0,                          /*tp_traverse*/
      0,                          /*tp_clear*/
      0,                          /*tp_richcompare*/
      0,                          /*tp_weaklistoffset*/
      0,                          /*tp_iter*/
      0,                          /*tp_iternext*/
      poll_methods,               /*tp_methods*/
  };
  
  #ifdef HAVE_SYS_DEVPOLL_H
  typedef struct {
      PyObject_HEAD
      int fd_devpoll;
      int max_n_fds;
      int n_fds;
      struct pollfd *fds;
  } devpollObject;
  
  static PyTypeObject devpoll_Type;
  
  static PyObject *
  devpoll_err_closed(void)
  {
      PyErr_SetString(PyExc_ValueError, "I/O operation on closed devpoll object");
      return NULL;
  }
  
  static int devpoll_flush(devpollObject *self)
  {
      int size, n;
  
      if (!self->n_fds) return 0;
  
      size = sizeof(struct pollfd)*self->n_fds;
      self->n_fds = 0;
  
      n = _Py_write(self->fd_devpoll, self->fds, size);
      if (n == -1)
          return -1;
  
      if (n < size) {
          /*
          ** Data writed to /dev/poll is a binary data structure. It is not
          ** clear what to do if a partial write occurred. For now, raise
          ** an exception and see if we actually found this problem in
          ** the wild.
          ** See http://bugs.python.org/issue6397.
          */
          PyErr_Format(PyExc_IOError, "failed to write all pollfds. "
                  "Please, report at http://bugs.python.org/. "
                  "Data to report: Size tried: %d, actual size written: %d.",
                  size, n);
          return -1;
      }
      return 0;
  }
  
  static PyObject *
  internal_devpoll_register(devpollObject *self, PyObject *args, int remove)
  {
      PyObject *o;
      int fd;
      unsigned short events = POLLIN | POLLPRI | POLLOUT;
  
      if (self->fd_devpoll < 0)
          return devpoll_err_closed();
  
      if (!PyArg_ParseTuple(args, "O|O&:register", &o, ushort_converter, &events))
          return NULL;
  
      fd = PyObject_AsFileDescriptor(o);
      if (fd == -1) return NULL;
  
      if (remove) {
          self->fds[self->n_fds].fd = fd;
          self->fds[self->n_fds].events = POLLREMOVE;
  
          if (++self->n_fds == self->max_n_fds) {
              if (devpoll_flush(self))
                  return NULL;
          }
      }
  
      self->fds[self->n_fds].fd = fd;
      self->fds[self->n_fds].events = (signed short)events;
  
      if (++self->n_fds == self->max_n_fds) {
          if (devpoll_flush(self))
              return NULL;
      }
  
      Py_RETURN_NONE;
  }
  
  PyDoc_STRVAR(devpoll_register_doc,
  "register(fd [, eventmask] ) -> None\n\n\
  Register a file descriptor with the polling object.\n\
  fd -- either an integer, or an object with a fileno() method returning an\n\
        int.\n\
  events -- an optional bitmask describing the type of events to check for");
  
  static PyObject *
  devpoll_register(devpollObject *self, PyObject *args)
  {
      return internal_devpoll_register(self, args, 0);
  }
  
  PyDoc_STRVAR(devpoll_modify_doc,
  "modify(fd[, eventmask]) -> None\n\n\
  Modify a possible already registered file descriptor.\n\
  fd -- either an integer, or an object with a fileno() method returning an\n\
        int.\n\
  events -- an optional bitmask describing the type of events to check for");
  
  static PyObject *
  devpoll_modify(devpollObject *self, PyObject *args)
  {
      return internal_devpoll_register(self, args, 1);
  }
  
  
  PyDoc_STRVAR(devpoll_unregister_doc,
  "unregister(fd) -> None\n\n\
  Remove a file descriptor being tracked by the polling object.");
  
  static PyObject *
  devpoll_unregister(devpollObject *self, PyObject *o)
  {
      int fd;
  
      if (self->fd_devpoll < 0)
          return devpoll_err_closed();
  
      fd = PyObject_AsFileDescriptor( o );
      if (fd == -1)
          return NULL;
  
      self->fds[self->n_fds].fd = fd;
      self->fds[self->n_fds].events = POLLREMOVE;
  
      if (++self->n_fds == self->max_n_fds) {
          if (devpoll_flush(self))
              return NULL;
      }
  
      Py_RETURN_NONE;
  }
  
  PyDoc_STRVAR(devpoll_poll_doc,
  "poll( [timeout] ) -> list of (fd, event) 2-tuples\n\n\
  Polls the set of registered file descriptors, returning a list containing \n\
  any descriptors that have events or errors to report.");
  
  static PyObject *
  devpoll_poll(devpollObject *self, PyObject *args)
  {
      struct dvpoll dvp;
      PyObject *result_list = NULL, *timeout_obj = NULL;
      int poll_result, i;
      PyObject *value, *num1, *num2;
      _PyTime_t timeout, ms, deadline = 0;
  
      if (self->fd_devpoll < 0)
          return devpoll_err_closed();
  
      if (!PyArg_ParseTuple(args, "|O:poll", &timeout_obj)) {
          return NULL;
      }
  
      /* Check values for timeout */
      if (timeout_obj == NULL || timeout_obj == Py_None) {
          timeout = -1;
          ms = -1;
      }
      else {
          if (_PyTime_FromMillisecondsObject(&timeout, timeout_obj,
                                             _PyTime_ROUND_CEILING) < 0) {
              if (PyErr_ExceptionMatches(PyExc_TypeError)) {
                  PyErr_SetString(PyExc_TypeError,
                                  "timeout must be an integer or None");
              }
              return NULL;
          }
  
          ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
          if (ms < -1 || ms > INT_MAX) {
              PyErr_SetString(PyExc_OverflowError, "timeout is too large");
              return NULL;
          }
      }
  
      if (devpoll_flush(self))
          return NULL;
  
      dvp.dp_fds = self->fds;
      dvp.dp_nfds = self->max_n_fds;
      dvp.dp_timeout = (int)ms;
  
      if (timeout >= 0)
          deadline = _PyTime_GetMonotonicClock() + timeout;
  
      do {
          /* call devpoll() */
          Py_BEGIN_ALLOW_THREADS
          errno = 0;
          poll_result = ioctl(self->fd_devpoll, DP_POLL, &dvp);
          Py_END_ALLOW_THREADS
  
          if (errno != EINTR)
              break;
  
          /* devpoll() was interrupted by a signal */
          if (PyErr_CheckSignals())
              return NULL;
  
          if (timeout >= 0) {
              timeout = deadline - _PyTime_GetMonotonicClock();
              if (timeout < 0) {
                  poll_result = 0;
                  break;
              }
              ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
              dvp.dp_timeout = (int)ms;
              /* retry devpoll() with the recomputed timeout */
          }
      } while (1);
  
      if (poll_result < 0) {
          PyErr_SetFromErrno(PyExc_IOError);
          return NULL;
      }
  
      /* build the result list */
      result_list = PyList_New(poll_result);
      if (!result_list)
          return NULL;
  
      for (i = 0; i < poll_result; i++) {
          num1 = PyLong_FromLong(self->fds[i].fd);
          num2 = PyLong_FromLong(self->fds[i].revents);
          if ((num1 == NULL) || (num2 == NULL)) {
              Py_XDECREF(num1);
              Py_XDECREF(num2);
              goto error;
          }
          value = PyTuple_Pack(2, num1, num2);
          Py_DECREF(num1);
          Py_DECREF(num2);
          if (value == NULL)
              goto error;
          if ((PyList_SetItem(result_list, i, value)) == -1) {
              Py_DECREF(value);
              goto error;
          }
      }
  
      return result_list;
  
    error:
      Py_DECREF(result_list);
      return NULL;
  }
  
  static int
  devpoll_internal_close(devpollObject *self)
  {
      int save_errno = 0;
      if (self->fd_devpoll >= 0) {
          int fd = self->fd_devpoll;
          self->fd_devpoll = -1;
          Py_BEGIN_ALLOW_THREADS
          if (close(fd) < 0)
              save_errno = errno;
          Py_END_ALLOW_THREADS
      }
      return save_errno;
  }
  
  static PyObject*
  devpoll_close(devpollObject *self)
  {
      errno = devpoll_internal_close(self);
      if (errno < 0) {
          PyErr_SetFromErrno(PyExc_OSError);
          return NULL;
      }
      Py_RETURN_NONE;
  }
  
  PyDoc_STRVAR(devpoll_close_doc,
  "close() -> None\n\
  \n\
  Close the devpoll file descriptor. Further operations on the devpoll\n\
  object will raise an exception.");
  
  static PyObject*
  devpoll_get_closed(devpollObject *self)
  {
      if (self->fd_devpoll < 0)
          Py_RETURN_TRUE;
      else
          Py_RETURN_FALSE;
  }
  
  static PyObject*
  devpoll_fileno(devpollObject *self)
  {
      if (self->fd_devpoll < 0)
          return devpoll_err_closed();
      return PyLong_FromLong(self->fd_devpoll);
  }
  
  PyDoc_STRVAR(devpoll_fileno_doc,
  "fileno() -> int\n\
  \n\
  Return the file descriptor.");
  
  static PyMethodDef devpoll_methods[] = {
      {"register",        (PyCFunction)devpoll_register,
       METH_VARARGS,  devpoll_register_doc},
      {"modify",          (PyCFunction)devpoll_modify,
       METH_VARARGS,  devpoll_modify_doc},
      {"unregister",      (PyCFunction)devpoll_unregister,
       METH_O,        devpoll_unregister_doc},
      {"poll",            (PyCFunction)devpoll_poll,
       METH_VARARGS,  devpoll_poll_doc},
      {"close",           (PyCFunction)devpoll_close,    METH_NOARGS,
       devpoll_close_doc},
      {"fileno",          (PyCFunction)devpoll_fileno,    METH_NOARGS,
       devpoll_fileno_doc},
      {NULL,              NULL}           /* sentinel */
  };
  
  static PyGetSetDef devpoll_getsetlist[] = {
      {"closed", (getter)devpoll_get_closed, NULL,
       "True if the devpoll object is closed"},
      {0},
  };
  
  static devpollObject *
  newDevPollObject(void)
  {
      devpollObject *self;
      int fd_devpoll, limit_result;
      struct pollfd *fds;
      struct rlimit limit;
  
      /*
      ** If we try to process more that getrlimit()
      ** fds, the kernel will give an error, so
      ** we set the limit here. It is a dynamic
      ** value, because we can change rlimit() anytime.
      */
      limit_result = getrlimit(RLIMIT_NOFILE, &limit);
      if (limit_result == -1) {
          PyErr_SetFromErrno(PyExc_OSError);
          return NULL;
      }
  
      fd_devpoll = _Py_open("/dev/poll", O_RDWR);
      if (fd_devpoll == -1)
          return NULL;
  
      fds = PyMem_NEW(struct pollfd, limit.rlim_cur);
      if (fds == NULL) {
          close(fd_devpoll);
          PyErr_NoMemory();
          return NULL;
      }
  
      self = PyObject_New(devpollObject, &devpoll_Type);
      if (self == NULL) {
          close(fd_devpoll);
          PyMem_DEL(fds);
          return NULL;
      }
      self->fd_devpoll = fd_devpoll;
      self->max_n_fds = limit.rlim_cur;
      self->n_fds = 0;
      self->fds = fds;
  
      return self;
  }
  
  static void
  devpoll_dealloc(devpollObject *self)
  {
      (void)devpoll_internal_close(self);
      PyMem_DEL(self->fds);
      PyObject_Del(self);
  }
  
  static PyTypeObject devpoll_Type = {
      /* The ob_type field must be initialized in the module init function
       * to be portable to Windows without using C++. */
      PyVarObject_HEAD_INIT(NULL, 0)
      "select.devpoll",           /*tp_name*/
      sizeof(devpollObject),      /*tp_basicsize*/
      0,                          /*tp_itemsize*/
      /* methods */
      (destructor)devpoll_dealloc, /*tp_dealloc*/
      0,                          /*tp_print*/
      0,                          /*tp_getattr*/
      0,                          /*tp_setattr*/
      0,                          /*tp_reserved*/
      0,                          /*tp_repr*/
      0,                          /*tp_as_number*/
      0,                          /*tp_as_sequence*/
      0,                          /*tp_as_mapping*/
      0,                          /*tp_hash*/
      0,                          /*tp_call*/
      0,                          /*tp_str*/
      0,                          /*tp_getattro*/
      0,                          /*tp_setattro*/
      0,                          /*tp_as_buffer*/
      Py_TPFLAGS_DEFAULT,         /*tp_flags*/
      0,                          /*tp_doc*/
      0,                          /*tp_traverse*/
      0,                          /*tp_clear*/
      0,                          /*tp_richcompare*/
      0,                          /*tp_weaklistoffset*/
      0,                          /*tp_iter*/
      0,                          /*tp_iternext*/
      devpoll_methods,            /*tp_methods*/
      0,                          /* tp_members */
      devpoll_getsetlist,         /* tp_getset */
  };
  #endif  /* HAVE_SYS_DEVPOLL_H */
  
  
  
  PyDoc_STRVAR(poll_doc,
  "Returns a polling object, which supports registering and\n\
  unregistering file descriptors, and then polling them for I/O events.");
  
  static PyObject *
  select_poll(PyObject *self, PyObject *unused)
  {
      return (PyObject *)newPollObject();
  }
  
  #ifdef HAVE_SYS_DEVPOLL_H
  PyDoc_STRVAR(devpoll_doc,
  "Returns a polling object, which supports registering and\n\
  unregistering file descriptors, and then polling them for I/O events.");
  
  static PyObject *
  select_devpoll(PyObject *self, PyObject *unused)
  {
      return (PyObject *)newDevPollObject();
  }
  #endif
  
  
  #ifdef __APPLE__
  /*
   * On some systems poll() sets errno on invalid file descriptors. We test
   * for this at runtime because this bug may be fixed or introduced between
   * OS releases.
   */
  static int select_have_broken_poll(void)
  {
      int poll_test;
      int filedes[2];
  
      struct pollfd poll_struct = { 0, POLLIN|POLLPRI|POLLOUT, 0 };
  
      /* Create a file descriptor to make invalid */
      if (pipe(filedes) < 0) {
          return 1;
      }
      poll_struct.fd = filedes[0];
      close(filedes[0]);
      close(filedes[1]);
      poll_test = poll(&poll_struct, 1, 0);
      if (poll_test < 0) {
          return 1;
      } else if (poll_test == 0 && poll_struct.revents != POLLNVAL) {
          return 1;
      }
      return 0;
  }
  #endif /* __APPLE__ */
  
  #endif /* HAVE_POLL */
  
  #ifdef HAVE_EPOLL
  /* **************************************************************************
   *                      epoll interface for Linux 2.6
   *
   * Written by Christian Heimes
   * Inspired by Twisted's _epoll.pyx and select.poll()
   */
  
  #ifdef HAVE_SYS_EPOLL_H
  #include <sys/epoll.h>
  #endif
  
  typedef struct {
      PyObject_HEAD
      SOCKET epfd;                        /* epoll control file descriptor */
  } pyEpoll_Object;
  
  static PyTypeObject pyEpoll_Type;
  #define pyepoll_CHECK(op) (PyObject_TypeCheck((op), &pyEpoll_Type))
  
  static PyObject *
  pyepoll_err_closed(void)
  {
      PyErr_SetString(PyExc_ValueError, "I/O operation on closed epoll object");
      return NULL;
  }
  
  static int
  pyepoll_internal_close(pyEpoll_Object *self)
  {
      int save_errno = 0;
      if (self->epfd >= 0) {
          int epfd = self->epfd;
          self->epfd = -1;
          Py_BEGIN_ALLOW_THREADS
          if (close(epfd) < 0)
              save_errno = errno;
          Py_END_ALLOW_THREADS
      }
      return save_errno;
  }
  
  static PyObject *
  newPyEpoll_Object(PyTypeObject *type, int sizehint, int flags, SOCKET fd)
  {
      pyEpoll_Object *self;
  
      assert(type != NULL && type->tp_alloc != NULL);
      self = (pyEpoll_Object *) type->tp_alloc(type, 0);
      if (self == NULL)
          return NULL;
  
      if (fd == -1) {
          Py_BEGIN_ALLOW_THREADS
  #ifdef HAVE_EPOLL_CREATE1
          flags |= EPOLL_CLOEXEC;
          if (flags)
              self->epfd = epoll_create1(flags);
          else
  #endif
          self->epfd = epoll_create(sizehint);
          Py_END_ALLOW_THREADS
      }
      else {
          self->epfd = fd;
      }
      if (self->epfd < 0) {
          Py_DECREF(self);
          PyErr_SetFromErrno(PyExc_OSError);
          return NULL;
      }
  
  #ifndef HAVE_EPOLL_CREATE1
      if (fd == -1 && _Py_set_inheritable(self->epfd, 0, NULL) < 0) {
          Py_DECREF(self);
          return NULL;
      }
  #endif
  
      return (PyObject *)self;
  }
  
  
  static PyObject *
  pyepoll_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
  {
      int flags = 0, sizehint = FD_SETSIZE - 1;
      static char *kwlist[] = {"sizehint", "flags", NULL};
  
      if (!PyArg_ParseTupleAndKeywords(args, kwds, "|ii:epoll", kwlist,
                                       &sizehint, &flags))
          return NULL;
      if (sizehint < 0) {
          PyErr_SetString(PyExc_ValueError, "negative sizehint");
          return NULL;
      }
  
      return newPyEpoll_Object(type, sizehint, flags, -1);
  }
  
  
  static void
  pyepoll_dealloc(pyEpoll_Object *self)
  {
      (void)pyepoll_internal_close(self);
      Py_TYPE(self)->tp_free(self);
  }
  
  static PyObject*
  pyepoll_close(pyEpoll_Object *self)
  {
      errno = pyepoll_internal_close(self);
      if (errno < 0) {
          PyErr_SetFromErrno(PyExc_OSError);
          return NULL;
      }
      Py_RETURN_NONE;
  }
  
  PyDoc_STRVAR(pyepoll_close_doc,
  "close() -> None\n\
  \n\
  Close the epoll control file descriptor. Further operations on the epoll\n\
  object will raise an exception.");
  
  static PyObject*
  pyepoll_get_closed(pyEpoll_Object *self)
  {
      if (self->epfd < 0)
          Py_RETURN_TRUE;
      else
          Py_RETURN_FALSE;
  }
  
  static PyObject*
  pyepoll_fileno(pyEpoll_Object *self)
  {
      if (self->epfd < 0)
          return pyepoll_err_closed();
      return PyLong_FromLong(self->epfd);
  }
  
  PyDoc_STRVAR(pyepoll_fileno_doc,
  "fileno() -> int\n\
  \n\
  Return the epoll control file descriptor.");
  
  static PyObject*
  pyepoll_fromfd(PyObject *cls, PyObject *args)
  {
      SOCKET fd;
  
      if (!PyArg_ParseTuple(args, "i:fromfd", &fd))
          return NULL;
  
      return newPyEpoll_Object((PyTypeObject*)cls, FD_SETSIZE - 1, 0, fd);
  }
  
  PyDoc_STRVAR(pyepoll_fromfd_doc,
  "fromfd(fd) -> epoll\n\
  \n\
  Create an epoll object from a given control fd.");
  
  static PyObject *
  pyepoll_internal_ctl(int epfd, int op, PyObject *pfd, unsigned int events)
  {
      struct epoll_event ev;
      int result;
      int fd;
  
      if (epfd < 0)
          return pyepoll_err_closed();
  
      fd = PyObject_AsFileDescriptor(pfd);
      if (fd == -1) {
          return NULL;
      }
  
      switch (op) {
      case EPOLL_CTL_ADD:
      case EPOLL_CTL_MOD:
          ev.events = events;
          ev.data.fd = fd;
          Py_BEGIN_ALLOW_THREADS
          result = epoll_ctl(epfd, op, fd, &ev);
          Py_END_ALLOW_THREADS
          break;
      case EPOLL_CTL_DEL:
          /* In kernel versions before 2.6.9, the EPOLL_CTL_DEL
           * operation required a non-NULL pointer in event, even
           * though this argument is ignored. */
          Py_BEGIN_ALLOW_THREADS
          result = epoll_ctl(epfd, op, fd, &ev);
          if (errno == EBADF) {
              /* fd already closed */
              result = 0;
              errno = 0;
          }
          Py_END_ALLOW_THREADS
          break;
      default:
          result = -1;
          errno = EINVAL;
      }
  
      if (result < 0) {
          PyErr_SetFromErrno(PyExc_OSError);
          return NULL;
      }
      Py_RETURN_NONE;
  }
  
  static PyObject *
  pyepoll_register(pyEpoll_Object *self, PyObject *args, PyObject *kwds)
  {
      PyObject *pfd;
      unsigned int events = EPOLLIN | EPOLLOUT | EPOLLPRI;
      static char *kwlist[] = {"fd", "eventmask", NULL};
  
      if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|I:register", kwlist,
                                       &pfd, &events)) {
          return NULL;
      }
  
      return pyepoll_internal_ctl(self->epfd, EPOLL_CTL_ADD, pfd, events);
  }
  
  PyDoc_STRVAR(pyepoll_register_doc,
  "register(fd[, eventmask]) -> None\n\
  \n\
  Registers a new fd or raises an OSError if the fd is already registered.\n\
  fd is the target file descriptor of the operation.\n\
  events is a bit set composed of the various EPOLL constants; the default\n\
  is EPOLL_IN | EPOLL_OUT | EPOLL_PRI.\n\
  \n\
  The epoll interface supports all file descriptors that support poll.");
  
  static PyObject *
  pyepoll_modify(pyEpoll_Object *self, PyObject *args, PyObject *kwds)
  {
      PyObject *pfd;
      unsigned int events;
      static char *kwlist[] = {"fd", "eventmask", NULL};
  
      if (!PyArg_ParseTupleAndKeywords(args, kwds, "OI:modify", kwlist,
                                       &pfd, &events)) {
          return NULL;
      }
  
      return pyepoll_internal_ctl(self->epfd, EPOLL_CTL_MOD, pfd, events);
  }
  
  PyDoc_STRVAR(pyepoll_modify_doc,
  "modify(fd, eventmask) -> None\n\
  \n\
  fd is the target file descriptor of the operation\n\
  events is a bit set composed of the various EPOLL constants");
  
  static PyObject *
  pyepoll_unregister(pyEpoll_Object *self, PyObject *args, PyObject *kwds)
  {
      PyObject *pfd;
      static char *kwlist[] = {"fd", NULL};
  
      if (!PyArg_ParseTupleAndKeywords(args, kwds, "O:unregister", kwlist,
                                       &pfd)) {
          return NULL;
      }
  
      return pyepoll_internal_ctl(self->epfd, EPOLL_CTL_DEL, pfd, 0);
  }
  
  PyDoc_STRVAR(pyepoll_unregister_doc,
  "unregister(fd) -> None\n\
  \n\
  fd is the target file descriptor of the operation.");
  
  static PyObject *
  pyepoll_poll(pyEpoll_Object *self, PyObject *args, PyObject *kwds)
  {
      static char *kwlist[] = {"timeout", "maxevents", NULL};
      PyObject *timeout_obj = NULL;
      int maxevents = -1;
      int nfds, i;
      PyObject *elist = NULL, *etuple = NULL;
      struct epoll_event *evs = NULL;
      _PyTime_t timeout, ms, deadline;
  
      if (self->epfd < 0)
          return pyepoll_err_closed();
  
      if (!PyArg_ParseTupleAndKeywords(args, kwds, "|Oi:poll", kwlist,
                                       &timeout_obj, &maxevents)) {
          return NULL;
      }
  
      if (timeout_obj == NULL || timeout_obj == Py_None) {
          timeout = -1;
          ms = -1;
          deadline = 0;   /* initialize to prevent gcc warning */
      }
      else {
          /* epoll_wait() has a resolution of 1 millisecond, round towards
             infinity to wait at least timeout seconds. */
          if (_PyTime_FromSecondsObject(&timeout, timeout_obj,
                                        _PyTime_ROUND_CEILING) < 0) {
              if (PyErr_ExceptionMatches(PyExc_TypeError)) {
                  PyErr_SetString(PyExc_TypeError,
                                  "timeout must be an integer or None");
              }
              return NULL;
          }
  
          ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
          if (ms < INT_MIN || ms > INT_MAX) {
              PyErr_SetString(PyExc_OverflowError, "timeout is too large");
              return NULL;
          }
  
          deadline = _PyTime_GetMonotonicClock() + timeout;
      }
  
      if (maxevents == -1) {
          maxevents = FD_SETSIZE-1;
      }
      else if (maxevents < 1) {
          PyErr_Format(PyExc_ValueError,
                       "maxevents must be greater than 0, got %d",
                       maxevents);
          return NULL;
      }
  
      evs = PyMem_New(struct epoll_event, maxevents);
      if (evs == NULL) {
          PyErr_NoMemory();
          return NULL;
      }
  
      do {
          Py_BEGIN_ALLOW_THREADS
          errno = 0;
          nfds = epoll_wait(self->epfd, evs, maxevents, (int)ms);
          Py_END_ALLOW_THREADS
  
          if (errno != EINTR)
              break;
  
          /* poll() was interrupted by a signal */
          if (PyErr_CheckSignals())
              goto error;
  
          if (timeout >= 0) {
              timeout = deadline - _PyTime_GetMonotonicClock();
              if (timeout < 0) {
                  nfds = 0;
                  break;
              }
              ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
              /* retry epoll_wait() with the recomputed timeout */
          }
      } while(1);
  
      if (nfds < 0) {
          PyErr_SetFromErrno(PyExc_OSError);
          goto error;
      }
  
      elist = PyList_New(nfds);
      if (elist == NULL) {
          goto error;
      }
  
      for (i = 0; i < nfds; i++) {
          etuple = Py_BuildValue("iI", evs[i].data.fd, evs[i].events);
          if (etuple == NULL) {
              Py_CLEAR(elist);
              goto error;
          }
          PyList_SET_ITEM(elist, i, etuple);
      }
  
      error:
      PyMem_Free(evs);
      return elist;
  }
  
  PyDoc_STRVAR(pyepoll_poll_doc,
  "poll([timeout=-1[, maxevents=-1]]) -> [(fd, events), (...)]\n\
  \n\
  Wait for events on the epoll file descriptor for a maximum time of timeout\n\
  in seconds (as float). -1 makes poll wait indefinitely.\n\
  Up to maxevents are returned to the caller.");
  
  static PyObject *
  pyepoll_enter(pyEpoll_Object *self, PyObject *args)
  {
      if (self->epfd < 0)
          return pyepoll_err_closed();
  
      Py_INCREF(self);
      return (PyObject *)self;
  }
  
  static PyObject *
  pyepoll_exit(PyObject *self, PyObject *args)
  {
      _Py_IDENTIFIER(close);
  
      return _PyObject_CallMethodId(self, &PyId_close, NULL);
  }
  
  static PyMethodDef pyepoll_methods[] = {
      {"fromfd",          (PyCFunction)pyepoll_fromfd,
       METH_VARARGS | METH_CLASS, pyepoll_fromfd_doc},
      {"close",           (PyCFunction)pyepoll_close,     METH_NOARGS,
       pyepoll_close_doc},
      {"fileno",          (PyCFunction)pyepoll_fileno,    METH_NOARGS,
       pyepoll_fileno_doc},
      {"modify",          (PyCFunction)pyepoll_modify,
       METH_VARARGS | METH_KEYWORDS,      pyepoll_modify_doc},
      {"register",        (PyCFunction)pyepoll_register,
       METH_VARARGS | METH_KEYWORDS,      pyepoll_register_doc},
      {"unregister",      (PyCFunction)pyepoll_unregister,
       METH_VARARGS | METH_KEYWORDS,      pyepoll_unregister_doc},
      {"poll",            (PyCFunction)pyepoll_poll,
       METH_VARARGS | METH_KEYWORDS,      pyepoll_poll_doc},
      {"__enter__",           (PyCFunction)pyepoll_enter,     METH_NOARGS,
       NULL},
      {"__exit__",           (PyCFunction)pyepoll_exit,     METH_VARARGS,
       NULL},
      {NULL,      NULL},
  };
  
  static PyGetSetDef pyepoll_getsetlist[] = {
      {"closed", (getter)pyepoll_get_closed, NULL,
       "True if the epoll handler is closed"},
      {0},
  };
  
  PyDoc_STRVAR(pyepoll_doc,
  "select.epoll(sizehint=-1, flags=0)\n\
  \n\
  Returns an epolling object\n\
  \n\
  sizehint must be a positive integer or -1 for the default size. The\n\
  sizehint is used to optimize internal data structures. It doesn't limit\n\
  the maximum number of monitored events.");
  
  static PyTypeObject pyEpoll_Type = {
      PyVarObject_HEAD_INIT(NULL, 0)
      "select.epoll",                                     /* tp_name */
      sizeof(pyEpoll_Object),                             /* tp_basicsize */
      0,                                                  /* tp_itemsize */
      (destructor)pyepoll_dealloc,                        /* tp_dealloc */
      0,                                                  /* tp_print */
      0,                                                  /* tp_getattr */
      0,                                                  /* tp_setattr */
      0,                                                  /* tp_reserved */
      0,                                                  /* tp_repr */
      0,                                                  /* tp_as_number */
      0,                                                  /* tp_as_sequence */
      0,                                                  /* tp_as_mapping */
      0,                                                  /* tp_hash */
      0,                                                  /* tp_call */
      0,                                                  /* tp_str */
      PyObject_GenericGetAttr,                            /* tp_getattro */
      0,                                                  /* tp_setattro */
      0,                                                  /* tp_as_buffer */
      Py_TPFLAGS_DEFAULT,                                 /* tp_flags */
      pyepoll_doc,                                        /* tp_doc */
      0,                                                  /* tp_traverse */
      0,                                                  /* tp_clear */
      0,                                                  /* tp_richcompare */
      0,                                                  /* tp_weaklistoffset */
      0,                                                  /* tp_iter */
      0,                                                  /* tp_iternext */
      pyepoll_methods,                                    /* tp_methods */
      0,                                                  /* tp_members */
      pyepoll_getsetlist,                                 /* tp_getset */
      0,                                                  /* tp_base */
      0,                                                  /* tp_dict */
      0,                                                  /* tp_descr_get */
      0,                                                  /* tp_descr_set */
      0,                                                  /* tp_dictoffset */
      0,                                                  /* tp_init */
      0,                                                  /* tp_alloc */
      pyepoll_new,                                        /* tp_new */
      0,                                                  /* tp_free */
  };
  
  #endif /* HAVE_EPOLL */
  
  #ifdef HAVE_KQUEUE
  /* **************************************************************************
   *                      kqueue interface for BSD
   *
   * Copyright (c) 2000 Doug White, 2006 James Knight, 2007 Christian Heimes
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #ifdef HAVE_SYS_EVENT_H
  #include <sys/event.h>
  #endif
  
  PyDoc_STRVAR(kqueue_event_doc,
  "kevent(ident, filter=KQ_FILTER_READ, flags=KQ_EV_ADD, fflags=0, data=0, udata=0)\n\
  \n\
  This object is the equivalent of the struct kevent for the C API.\n\
  \n\
  See the kqueue manpage for more detailed information about the meaning\n\
  of the arguments.\n\
  \n\
  One minor note: while you might hope that udata could store a\n\
  reference to a python object, it cannot, because it is impossible to\n\
  keep a proper reference count of the object once it's passed into the\n\
  kernel. Therefore, I have restricted it to only storing an integer.  I\n\
  recommend ignoring it and simply using the 'ident' field to key off\n\
  of. You could also set up a dictionary on the python side to store a\n\
  udata->object mapping.");
  
  typedef struct {
      PyObject_HEAD
      struct kevent e;
  } kqueue_event_Object;
  
  static PyTypeObject kqueue_event_Type;
  
  #define kqueue_event_Check(op) (PyObject_TypeCheck((op), &kqueue_event_Type))
  
  typedef struct {
      PyObject_HEAD
      SOCKET kqfd;                /* kqueue control fd */
  } kqueue_queue_Object;
  
  static PyTypeObject kqueue_queue_Type;
  
  #define kqueue_queue_Check(op) (PyObject_TypeCheck((op), &kqueue_queue_Type))
  
  #if (SIZEOF_UINTPTR_T != SIZEOF_VOID_P)
  #   error uintptr_t does not match void *!
  #elif (SIZEOF_UINTPTR_T == SIZEOF_LONG_LONG)
  #   define T_UINTPTRT         T_ULONGLONG
  #   define T_INTPTRT          T_LONGLONG
  #   define PyLong_AsUintptr_t PyLong_AsUnsignedLongLong
  #   define UINTPTRT_FMT_UNIT  "K"
  #   define INTPTRT_FMT_UNIT   "L"
  #elif (SIZEOF_UINTPTR_T == SIZEOF_LONG)
  #   define T_UINTPTRT         T_ULONG
  #   define T_INTPTRT          T_LONG
  #   define PyLong_AsUintptr_t PyLong_AsUnsignedLong
  #   define UINTPTRT_FMT_UNIT  "k"
  #   define INTPTRT_FMT_UNIT   "l"
  #elif (SIZEOF_UINTPTR_T == SIZEOF_INT)
  #   define T_UINTPTRT         T_UINT
  #   define T_INTPTRT          T_INT
  #   define PyLong_AsUintptr_t PyLong_AsUnsignedLong
  #   define UINTPTRT_FMT_UNIT  "I"
  #   define INTPTRT_FMT_UNIT   "i"
  #else
  #   error uintptr_t does not match int, long, or long long!
  #endif
  
  /*
   * kevent is not standard and its members vary across BSDs.
   */
  #if !defined(__OpenBSD__)
  #   define IDENT_TYPE  T_UINTPTRT
  #   define IDENT_CAST  Py_intptr_t
  #   define DATA_TYPE   T_INTPTRT
  #   define DATA_FMT_UNIT INTPTRT_FMT_UNIT
  #   define IDENT_AsType PyLong_AsUintptr_t
  #else
  #   define IDENT_TYPE  T_UINT
  #   define IDENT_CAST  int
  #   define DATA_TYPE   T_INT
  #   define DATA_FMT_UNIT "i"
  #   define IDENT_AsType PyLong_AsUnsignedLong
  #endif
  
  /* Unfortunately, we can't store python objects in udata, because
   * kevents in the kernel can be removed without warning, which would
   * forever lose the refcount on the object stored with it.
   */
  
  #define KQ_OFF(x) offsetof(kqueue_event_Object, x)
  static struct PyMemberDef kqueue_event_members[] = {
      {"ident",           IDENT_TYPE,     KQ_OFF(e.ident)},
      {"filter",          T_SHORT,        KQ_OFF(e.filter)},
      {"flags",           T_USHORT,       KQ_OFF(e.flags)},
      {"fflags",          T_UINT,         KQ_OFF(e.fflags)},
      {"data",            DATA_TYPE,      KQ_OFF(e.data)},
      {"udata",           T_UINTPTRT,     KQ_OFF(e.udata)},
      {NULL} /* Sentinel */
  };
  #undef KQ_OFF
  
  static PyObject *
  
  kqueue_event_repr(kqueue_event_Object *s)
  {
      char buf[1024];
      PyOS_snprintf(
          buf, sizeof(buf),
          "<select.kevent ident=%zu filter=%d flags=0x%x fflags=0x%x "
          "data=0x%zd udata=%p>",
          (size_t)(s->e.ident), s->e.filter, s->e.flags,
          s->e.fflags, (Py_ssize_t)(s->e.data), s->e.udata);
      return PyUnicode_FromString(buf);
  }
  
  static int
  kqueue_event_init(kqueue_event_Object *self, PyObject *args, PyObject *kwds)
  {
      PyObject *pfd;
      static char *kwlist[] = {"ident", "filter", "flags", "fflags",
                               "data", "udata", NULL};
      static char *fmt = "O|hHI" DATA_FMT_UNIT UINTPTRT_FMT_UNIT ":kevent";
  
      EV_SET(&(self->e), 0, EVFILT_READ, EV_ADD, 0, 0, 0); /* defaults */
  
      if (!PyArg_ParseTupleAndKeywords(args, kwds, fmt, kwlist,
          &pfd, &(self->e.filter), &(self->e.flags),
          &(self->e.fflags), &(self->e.data), &(self->e.udata))) {
          return -1;
      }
  
      if (PyLong_Check(pfd)
  #if IDENT_TYPE == T_UINT
          && PyLong_AsUnsignedLong(pfd) <= UINT_MAX
  #endif
      ) {
          self->e.ident = IDENT_AsType(pfd);
      }
      else {
          self->e.ident = PyObject_AsFileDescriptor(pfd);
      }
      if (PyErr_Occurred()) {
          return -1;
      }
      return 0;
  }
  
  static PyObject *
  kqueue_event_richcompare(kqueue_event_Object *s, kqueue_event_Object *o,
                           int op)
  {
      Py_intptr_t result = 0;
  
      if (!kqueue_event_Check(o)) {
          if (op == Py_EQ || op == Py_NE) {
              PyObject *res = op == Py_EQ ? Py_False : Py_True;
              Py_INCREF(res);
              return res;
          }
          PyErr_Format(PyExc_TypeError,
              "can't compare %.200s to %.200s",
              Py_TYPE(s)->tp_name, Py_TYPE(o)->tp_name);
          return NULL;
      }
      if (((result = (IDENT_CAST)(s->e.ident - o->e.ident)) == 0) &&
          ((result = s->e.filter - o->e.filter) == 0) &&
          ((result = s->e.flags - o->e.flags) == 0) &&
          ((result = (int)(s->e.fflags - o->e.fflags)) == 0) &&
          ((result = s->e.data - o->e.data) == 0) &&
          ((result = s->e.udata - o->e.udata) == 0)
         ) {
          result = 0;
      }
  
      switch (op) {
      case Py_EQ:
          result = (result == 0);
          break;
      case Py_NE:
          result = (result != 0);
          break;
      case Py_LE:
          result = (result <= 0);
          break;
      case Py_GE:
          result = (result >= 0);
          break;
      case Py_LT:
          result = (result < 0);
          break;
      case Py_GT:
          result = (result > 0);
          break;
      }
      return PyBool_FromLong((long)result);
  }
  
  static PyTypeObject kqueue_event_Type = {
      PyVarObject_HEAD_INIT(NULL, 0)
      "select.kevent",                                    /* tp_name */
      sizeof(kqueue_event_Object),                        /* tp_basicsize */
      0,                                                  /* tp_itemsize */
      0,                                                  /* tp_dealloc */
      0,                                                  /* tp_print */
      0,                                                  /* tp_getattr */
      0,                                                  /* tp_setattr */
      0,                                                  /* tp_reserved */
      (reprfunc)kqueue_event_repr,                        /* tp_repr */
      0,                                                  /* tp_as_number */
      0,                                                  /* tp_as_sequence */
      0,                                                  /* tp_as_mapping */
      0,                                                  /* tp_hash */
      0,                                                  /* tp_call */
      0,                                                  /* tp_str */
      0,                                                  /* tp_getattro */
      0,                                                  /* tp_setattro */
      0,                                                  /* tp_as_buffer */
      Py_TPFLAGS_DEFAULT,                                 /* tp_flags */
      kqueue_event_doc,                                   /* tp_doc */
      0,                                                  /* tp_traverse */
      0,                                                  /* tp_clear */
      (richcmpfunc)kqueue_event_richcompare,              /* tp_richcompare */
      0,                                                  /* tp_weaklistoffset */
      0,                                                  /* tp_iter */
      0,                                                  /* tp_iternext */
      0,                                                  /* tp_methods */
      kqueue_event_members,                               /* tp_members */
      0,                                                  /* tp_getset */
      0,                                                  /* tp_base */
      0,                                                  /* tp_dict */
      0,                                                  /* tp_descr_get */
      0,                                                  /* tp_descr_set */
      0,                                                  /* tp_dictoffset */
      (initproc)kqueue_event_init,                        /* tp_init */
      0,                                                  /* tp_alloc */
      0,                                                  /* tp_new */
      0,                                                  /* tp_free */
  };
  
  static PyObject *
  kqueue_queue_err_closed(void)
  {
      PyErr_SetString(PyExc_ValueError, "I/O operation on closed kqueue object");
      return NULL;
  }
  
  static int
  kqueue_queue_internal_close(kqueue_queue_Object *self)
  {
      int save_errno = 0;
      if (self->kqfd >= 0) {
          int kqfd = self->kqfd;
          self->kqfd = -1;
          Py_BEGIN_ALLOW_THREADS
          if (close(kqfd) < 0)
              save_errno = errno;
          Py_END_ALLOW_THREADS
      }
      return save_errno;
  }
  
  static PyObject *
  newKqueue_Object(PyTypeObject *type, SOCKET fd)
  {
      kqueue_queue_Object *self;
      assert(type != NULL && type->tp_alloc != NULL);
      self = (kqueue_queue_Object *) type->tp_alloc(type, 0);
      if (self == NULL) {
          return NULL;
      }
  
      if (fd == -1) {
          Py_BEGIN_ALLOW_THREADS
          self->kqfd = kqueue();
          Py_END_ALLOW_THREADS
      }
      else {
          self->kqfd = fd;
      }
      if (self->kqfd < 0) {
          Py_DECREF(self);
          PyErr_SetFromErrno(PyExc_OSError);
          return NULL;
      }
  
      if (fd == -1) {
          if (_Py_set_inheritable(self->kqfd, 0, NULL) < 0) {
              Py_DECREF(self);
              return NULL;
          }
      }
      return (PyObject *)self;
  }
  
  static PyObject *
  kqueue_queue_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
  {
      if ((args != NULL && PyObject_Size(args)) ||
                      (kwds != NULL && PyObject_Size(kwds))) {
          PyErr_SetString(PyExc_ValueError,
                          "select.kqueue doesn't accept arguments");
          return NULL;
      }
  
      return newKqueue_Object(type, -1);
  }
  
  static void
  kqueue_queue_dealloc(kqueue_queue_Object *self)
  {
      kqueue_queue_internal_close(self);
      Py_TYPE(self)->tp_free(self);
  }
  
  static PyObject*
  kqueue_queue_close(kqueue_queue_Object *self)
  {
      errno = kqueue_queue_internal_close(self);
      if (errno < 0) {
          PyErr_SetFromErrno(PyExc_OSError);
          return NULL;
      }
      Py_RETURN_NONE;
  }
  
  PyDoc_STRVAR(kqueue_queue_close_doc,
  "close() -> None\n\
  \n\
  Close the kqueue control file descriptor. Further operations on the kqueue\n\
  object will raise an exception.");
  
  static PyObject*
  kqueue_queue_get_closed(kqueue_queue_Object *self)
  {
      if (self->kqfd < 0)
          Py_RETURN_TRUE;
      else
          Py_RETURN_FALSE;
  }
  
  static PyObject*
  kqueue_queue_fileno(kqueue_queue_Object *self)
  {
      if (self->kqfd < 0)
          return kqueue_queue_err_closed();
      return PyLong_FromLong(self->kqfd);
  }
  
  PyDoc_STRVAR(kqueue_queue_fileno_doc,
  "fileno() -> int\n\
  \n\
  Return the kqueue control file descriptor.");
  
  static PyObject*
  kqueue_queue_fromfd(PyObject *cls, PyObject *args)
  {
      SOCKET fd;
  
      if (!PyArg_ParseTuple(args, "i:fromfd", &fd))
          return NULL;
  
      return newKqueue_Object((PyTypeObject*)cls, fd);
  }
  
  PyDoc_STRVAR(kqueue_queue_fromfd_doc,
  "fromfd(fd) -> kqueue\n\
  \n\
  Create a kqueue object from a given control fd.");
  
  static PyObject *
  kqueue_queue_control(kqueue_queue_Object *self, PyObject *args)
  {
      int nevents = 0;
      int gotevents = 0;
      int nchanges = 0;
      int i = 0;
      PyObject *otimeout = NULL;
      PyObject *ch = NULL;
      PyObject *it = NULL, *ei = NULL;
      PyObject *result = NULL;
      struct kevent *evl = NULL;
      struct kevent *chl = NULL;
      struct timespec timeoutspec;
      struct timespec *ptimeoutspec;
      _PyTime_t timeout, deadline = 0;
  
      if (self->kqfd < 0)
          return kqueue_queue_err_closed();
  
      if (!PyArg_ParseTuple(args, "Oi|O:control", &ch, &nevents, &otimeout))
          return NULL;
  
      if (nevents < 0) {
          PyErr_Format(PyExc_ValueError,
              "Length of eventlist must be 0 or positive, got %d",
              nevents);
          return NULL;
      }
  
      if (otimeout == Py_None || otimeout == NULL) {
          ptimeoutspec = NULL;
      }
      else {
          if (_PyTime_FromSecondsObject(&timeout,
                                        otimeout, _PyTime_ROUND_CEILING) < 0) {
              PyErr_Format(PyExc_TypeError,
                  "timeout argument must be an number "
                  "or None, got %.200s",
                  Py_TYPE(otimeout)->tp_name);
              return NULL;
          }
  
          if (_PyTime_AsTimespec(timeout, &timeoutspec) == -1)
              return NULL;
  
          if (timeoutspec.tv_sec < 0) {
              PyErr_SetString(PyExc_ValueError,
                              "timeout must be positive or None");
              return NULL;
          }
          ptimeoutspec = &timeoutspec;
      }
  
      if (ch != NULL && ch != Py_None) {
          it = PyObject_GetIter(ch);
          if (it == NULL) {
              PyErr_SetString(PyExc_TypeError,
                              "changelist is not iterable");
              return NULL;
          }
          nchanges = PyObject_Size(ch);
          if (nchanges < 0) {
              goto error;
          }
  
          chl = PyMem_New(struct kevent, nchanges);
          if (chl == NULL) {
              PyErr_NoMemory();
              goto error;
          }
          i = 0;
          while ((ei = PyIter_Next(it)) != NULL) {
              if (!kqueue_event_Check(ei)) {
                  Py_DECREF(ei);
                  PyErr_SetString(PyExc_TypeError,
                      "changelist must be an iterable of "
                      "select.kevent objects");
                  goto error;
              } else {
                  chl[i++] = ((kqueue_event_Object *)ei)->e;
              }
              Py_DECREF(ei);
          }
      }
      Py_CLEAR(it);
  
      /* event list */
      if (nevents) {
          evl = PyMem_New(struct kevent, nevents);
          if (evl == NULL) {
              PyErr_NoMemory();
              goto error;
          }
      }
  
      if (ptimeoutspec)
          deadline = _PyTime_GetMonotonicClock() + timeout;
  
      do {
          Py_BEGIN_ALLOW_THREADS
          errno = 0;
          gotevents = kevent(self->kqfd, chl, nchanges,
                             evl, nevents, ptimeoutspec);
          Py_END_ALLOW_THREADS
  
          if (errno != EINTR)
              break;
  
          /* kevent() was interrupted by a signal */
          if (PyErr_CheckSignals())
              goto error;
  
          if (ptimeoutspec) {
              timeout = deadline - _PyTime_GetMonotonicClock();
              if (timeout < 0) {
                  gotevents = 0;
                  break;
              }
              if (_PyTime_AsTimespec(timeout, &timeoutspec) == -1)
                  goto error;
              /* retry kevent() with the recomputed timeout */
          }
      } while (1);
  
      if (gotevents == -1) {
          PyErr_SetFromErrno(PyExc_OSError);
          goto error;
      }
  
      result = PyList_New(gotevents);
      if (result == NULL) {
          goto error;
      }
  
      for (i = 0; i < gotevents; i++) {
          kqueue_event_Object *ch;
  
          ch = PyObject_New(kqueue_event_Object, &kqueue_event_Type);
          if (ch == NULL) {
              goto error;
          }
          ch->e = evl[i];
          PyList_SET_ITEM(result, i, (PyObject *)ch);
      }
      PyMem_Free(chl);
      PyMem_Free(evl);
      return result;
  
      error:
      PyMem_Free(chl);
      PyMem_Free(evl);
      Py_XDECREF(result);
      Py_XDECREF(it);
      return NULL;
  }
  
  PyDoc_STRVAR(kqueue_queue_control_doc,
  "control(changelist, max_events[, timeout=None]) -> eventlist\n\
  \n\
  Calls the kernel kevent function.\n\
  - changelist must be a list of kevent objects describing the changes\n\
    to be made to the kernel's watch list or None.\n\
  - max_events lets you specify the maximum number of events that the\n\
    kernel will return.\n\
  - timeout is the maximum time to wait in seconds, or else None,\n\
    to wait forever. timeout accepts floats for smaller timeouts, too.");
  
  
  static PyMethodDef kqueue_queue_methods[] = {
      {"fromfd",          (PyCFunction)kqueue_queue_fromfd,
       METH_VARARGS | METH_CLASS, kqueue_queue_fromfd_doc},
      {"close",           (PyCFunction)kqueue_queue_close,        METH_NOARGS,
       kqueue_queue_close_doc},
      {"fileno",          (PyCFunction)kqueue_queue_fileno,       METH_NOARGS,
       kqueue_queue_fileno_doc},
      {"control",         (PyCFunction)kqueue_queue_control,
       METH_VARARGS ,     kqueue_queue_control_doc},
      {NULL,      NULL},
  };
  
  static PyGetSetDef kqueue_queue_getsetlist[] = {
      {"closed", (getter)kqueue_queue_get_closed, NULL,
       "True if the kqueue handler is closed"},
      {0},
  };
  
  PyDoc_STRVAR(kqueue_queue_doc,
  "Kqueue syscall wrapper.\n\
  \n\
  For example, to start watching a socket for input:\n\
  >>> kq = kqueue()\n\
  >>> sock = socket()\n\
  >>> sock.connect((host, port))\n\
  >>> kq.control([kevent(sock, KQ_FILTER_WRITE, KQ_EV_ADD)], 0)\n\
  \n\
  To wait one second for it to become writeable:\n\
  >>> kq.control(None, 1, 1000)\n\
  \n\
  To stop listening:\n\
  >>> kq.control([kevent(sock, KQ_FILTER_WRITE, KQ_EV_DELETE)], 0)");
  
  static PyTypeObject kqueue_queue_Type = {
      PyVarObject_HEAD_INIT(NULL, 0)
      "select.kqueue",                                    /* tp_name */
      sizeof(kqueue_queue_Object),                        /* tp_basicsize */
      0,                                                  /* tp_itemsize */
      (destructor)kqueue_queue_dealloc,                   /* tp_dealloc */
      0,                                                  /* tp_print */
      0,                                                  /* tp_getattr */
      0,                                                  /* tp_setattr */
      0,                                                  /* tp_reserved */
      0,                                                  /* tp_repr */
      0,                                                  /* tp_as_number */
      0,                                                  /* tp_as_sequence */
      0,                                                  /* tp_as_mapping */
      0,                                                  /* tp_hash */
      0,                                                  /* tp_call */
      0,                                                  /* tp_str */
      0,                                                  /* tp_getattro */
      0,                                                  /* tp_setattro */
      0,                                                  /* tp_as_buffer */
      Py_TPFLAGS_DEFAULT,                                 /* tp_flags */
      kqueue_queue_doc,                                   /* tp_doc */
      0,                                                  /* tp_traverse */
      0,                                                  /* tp_clear */
      0,                                                  /* tp_richcompare */
      0,                                                  /* tp_weaklistoffset */
      0,                                                  /* tp_iter */
      0,                                                  /* tp_iternext */
      kqueue_queue_methods,                               /* tp_methods */
      0,                                                  /* tp_members */
      kqueue_queue_getsetlist,                            /* tp_getset */
      0,                                                  /* tp_base */
      0,                                                  /* tp_dict */
      0,                                                  /* tp_descr_get */
      0,                                                  /* tp_descr_set */
      0,                                                  /* tp_dictoffset */
      0,                                                  /* tp_init */
      0,                                                  /* tp_alloc */
      kqueue_queue_new,                                   /* tp_new */
      0,                                                  /* tp_free */
  };
  
  #endif /* HAVE_KQUEUE */
  
  
  
  
  
  /* ************************************************************************ */
  
  PyDoc_STRVAR(select_doc,
  "select(rlist, wlist, xlist[, timeout]) -> (rlist, wlist, xlist)\n\
  \n\
  Wait until one or more file descriptors are ready for some kind of I/O.\n\
  The first three arguments are sequences of file descriptors to be waited for:\n\
  rlist -- wait until ready for reading\n\
  wlist -- wait until ready for writing\n\
  xlist -- wait for an ``exceptional condition''\n\
  If only one kind of condition is required, pass [] for the other lists.\n\
  A file descriptor is either a socket or file object, or a small integer\n\
  gotten from a fileno() method call on one of those.\n\
  \n\
  The optional 4th argument specifies a timeout in seconds; it may be\n\
  a floating point number to specify fractions of seconds.  If it is absent\n\
  or None, the call will never time out.\n\
  \n\
  The return value is a tuple of three lists corresponding to the first three\n\
  arguments; each contains the subset of the corresponding file descriptors\n\
  that are ready.\n\
  \n\
  *** IMPORTANT NOTICE ***\n\
  On Windows only sockets are supported; on Unix, all file\n\
  descriptors can be used.");
  
  static PyMethodDef select_methods[] = {
      {"select",          select_select,  METH_VARARGS,   select_doc},
  #if defined(HAVE_POLL) && !defined(HAVE_BROKEN_POLL)
      {"poll",            select_poll,    METH_NOARGS,    poll_doc},
  #endif /* HAVE_POLL */
  #ifdef HAVE_SYS_DEVPOLL_H
      {"devpoll",         select_devpoll, METH_NOARGS,    devpoll_doc},
  #endif
      {0,         0},     /* sentinel */
  };
  
  PyDoc_STRVAR(module_doc,
  "This module supports asynchronous I/O on multiple file descriptors.\n\
  \n\
  *** IMPORTANT NOTICE ***\n\
  On Windows only sockets are supported; on Unix, all file descriptors.");
  
  
  static struct PyModuleDef selectmodule = {
      PyModuleDef_HEAD_INIT,
      "select",
      module_doc,
      -1,
      select_methods,
      NULL,
      NULL,
      NULL,
      NULL
  };
  
  
  
  
  PyMODINIT_FUNC
  PyInit_select(void)
  {
      PyObject *m;
      m = PyModule_Create(&selectmodule);
      if (m == NULL)
          return NULL;
  
      Py_INCREF(PyExc_OSError);
      PyModule_AddObject(m, "error", PyExc_OSError);
  
  #ifdef PIPE_BUF
  #ifdef HAVE_BROKEN_PIPE_BUF
  #undef PIPE_BUF
  #define PIPE_BUF 512
  #endif
      PyModule_AddIntMacro(m, PIPE_BUF);
  #endif
  
  #if defined(HAVE_POLL) && !defined(HAVE_BROKEN_POLL)
  #ifdef __APPLE__
      if (select_have_broken_poll()) {
          if (PyObject_DelAttrString(m, "poll") == -1) {
              PyErr_Clear();
          }
      } else {
  #else
      {
  #endif
          if (PyType_Ready(&poll_Type) < 0)
              return NULL;
          PyModule_AddIntMacro(m, POLLIN);
          PyModule_AddIntMacro(m, POLLPRI);
          PyModule_AddIntMacro(m, POLLOUT);
          PyModule_AddIntMacro(m, POLLERR);
          PyModule_AddIntMacro(m, POLLHUP);
          PyModule_AddIntMacro(m, POLLNVAL);
  
  #ifdef POLLRDNORM
          PyModule_AddIntMacro(m, POLLRDNORM);
  #endif
  #ifdef POLLRDBAND
          PyModule_AddIntMacro(m, POLLRDBAND);
  #endif
  #ifdef POLLWRNORM
          PyModule_AddIntMacro(m, POLLWRNORM);
  #endif
  #ifdef POLLWRBAND
          PyModule_AddIntMacro(m, POLLWRBAND);
  #endif
  #ifdef POLLMSG
          PyModule_AddIntMacro(m, POLLMSG);
  #endif
      }
  #endif /* HAVE_POLL */
  
  #ifdef HAVE_SYS_DEVPOLL_H
      if (PyType_Ready(&devpoll_Type) < 0)
          return NULL;
  #endif
  
  #ifdef HAVE_EPOLL
      Py_TYPE(&pyEpoll_Type) = &PyType_Type;
      if (PyType_Ready(&pyEpoll_Type) < 0)
          return NULL;
  
      Py_INCREF(&pyEpoll_Type);
      PyModule_AddObject(m, "epoll", (PyObject *) &pyEpoll_Type);
  
      PyModule_AddIntMacro(m, EPOLLIN);
      PyModule_AddIntMacro(m, EPOLLOUT);
      PyModule_AddIntMacro(m, EPOLLPRI);
      PyModule_AddIntMacro(m, EPOLLERR);
      PyModule_AddIntMacro(m, EPOLLHUP);
      PyModule_AddIntMacro(m, EPOLLET);
  #ifdef EPOLLONESHOT
      /* Kernel 2.6.2+ */
      PyModule_AddIntMacro(m, EPOLLONESHOT);
  #endif
      /* PyModule_AddIntConstant(m, "EPOLL_RDHUP", EPOLLRDHUP); */
  
  #ifdef EPOLLRDNORM
      PyModule_AddIntMacro(m, EPOLLRDNORM);
  #endif
  #ifdef EPOLLRDBAND
      PyModule_AddIntMacro(m, EPOLLRDBAND);
  #endif
  #ifdef EPOLLWRNORM
      PyModule_AddIntMacro(m, EPOLLWRNORM);
  #endif
  #ifdef EPOLLWRBAND
      PyModule_AddIntMacro(m, EPOLLWRBAND);
  #endif
  #ifdef EPOLLMSG
      PyModule_AddIntMacro(m, EPOLLMSG);
  #endif
  
  #ifdef EPOLL_CLOEXEC
      PyModule_AddIntMacro(m, EPOLL_CLOEXEC);
  #endif
  #endif /* HAVE_EPOLL */
  
  #ifdef HAVE_KQUEUE
      kqueue_event_Type.tp_new = PyType_GenericNew;
      Py_TYPE(&kqueue_event_Type) = &PyType_Type;
      if(PyType_Ready(&kqueue_event_Type) < 0)
          return NULL;
  
      Py_INCREF(&kqueue_event_Type);
      PyModule_AddObject(m, "kevent", (PyObject *)&kqueue_event_Type);
  
      Py_TYPE(&kqueue_queue_Type) = &PyType_Type;
      if(PyType_Ready(&kqueue_queue_Type) < 0)
          return NULL;
      Py_INCREF(&kqueue_queue_Type);
      PyModule_AddObject(m, "kqueue", (PyObject *)&kqueue_queue_Type);
  
      /* event filters */
      PyModule_AddIntConstant(m, "KQ_FILTER_READ", EVFILT_READ);
      PyModule_AddIntConstant(m, "KQ_FILTER_WRITE", EVFILT_WRITE);
      PyModule_AddIntConstant(m, "KQ_FILTER_AIO", EVFILT_AIO);
      PyModule_AddIntConstant(m, "KQ_FILTER_VNODE", EVFILT_VNODE);
      PyModule_AddIntConstant(m, "KQ_FILTER_PROC", EVFILT_PROC);
  #ifdef EVFILT_NETDEV
      PyModule_AddIntConstant(m, "KQ_FILTER_NETDEV", EVFILT_NETDEV);
  #endif
      PyModule_AddIntConstant(m, "KQ_FILTER_SIGNAL", EVFILT_SIGNAL);
      PyModule_AddIntConstant(m, "KQ_FILTER_TIMER", EVFILT_TIMER);
  
      /* event flags */
      PyModule_AddIntConstant(m, "KQ_EV_ADD", EV_ADD);
      PyModule_AddIntConstant(m, "KQ_EV_DELETE", EV_DELETE);
      PyModule_AddIntConstant(m, "KQ_EV_ENABLE", EV_ENABLE);
      PyModule_AddIntConstant(m, "KQ_EV_DISABLE", EV_DISABLE);
      PyModule_AddIntConstant(m, "KQ_EV_ONESHOT", EV_ONESHOT);
      PyModule_AddIntConstant(m, "KQ_EV_CLEAR", EV_CLEAR);
  
      PyModule_AddIntConstant(m, "KQ_EV_SYSFLAGS", EV_SYSFLAGS);
      PyModule_AddIntConstant(m, "KQ_EV_FLAG1", EV_FLAG1);
  
      PyModule_AddIntConstant(m, "KQ_EV_EOF", EV_EOF);
      PyModule_AddIntConstant(m, "KQ_EV_ERROR", EV_ERROR);
  
      /* READ WRITE filter flag */
      PyModule_AddIntConstant(m, "KQ_NOTE_LOWAT", NOTE_LOWAT);
  
      /* VNODE filter flags  */
      PyModule_AddIntConstant(m, "KQ_NOTE_DELETE", NOTE_DELETE);
      PyModule_AddIntConstant(m, "KQ_NOTE_WRITE", NOTE_WRITE);
      PyModule_AddIntConstant(m, "KQ_NOTE_EXTEND", NOTE_EXTEND);
      PyModule_AddIntConstant(m, "KQ_NOTE_ATTRIB", NOTE_ATTRIB);
      PyModule_AddIntConstant(m, "KQ_NOTE_LINK", NOTE_LINK);
      PyModule_AddIntConstant(m, "KQ_NOTE_RENAME", NOTE_RENAME);
      PyModule_AddIntConstant(m, "KQ_NOTE_REVOKE", NOTE_REVOKE);
  
      /* PROC filter flags  */
      PyModule_AddIntConstant(m, "KQ_NOTE_EXIT", NOTE_EXIT);
      PyModule_AddIntConstant(m, "KQ_NOTE_FORK", NOTE_FORK);
      PyModule_AddIntConstant(m, "KQ_NOTE_EXEC", NOTE_EXEC);
      PyModule_AddIntConstant(m, "KQ_NOTE_PCTRLMASK", NOTE_PCTRLMASK);
      PyModule_AddIntConstant(m, "KQ_NOTE_PDATAMASK", NOTE_PDATAMASK);
  
      PyModule_AddIntConstant(m, "KQ_NOTE_TRACK", NOTE_TRACK);
      PyModule_AddIntConstant(m, "KQ_NOTE_CHILD", NOTE_CHILD);
      PyModule_AddIntConstant(m, "KQ_NOTE_TRACKERR", NOTE_TRACKERR);
  
      /* NETDEV filter flags */
  #ifdef EVFILT_NETDEV
      PyModule_AddIntConstant(m, "KQ_NOTE_LINKUP", NOTE_LINKUP);
      PyModule_AddIntConstant(m, "KQ_NOTE_LINKDOWN", NOTE_LINKDOWN);
      PyModule_AddIntConstant(m, "KQ_NOTE_LINKINV", NOTE_LINKINV);
  #endif
  
  #endif /* HAVE_KQUEUE */
      return m;
  }
  