cpython/Modules/selectmodule.c at 3.5 · python/cpython · GitHub

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/* 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\

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\

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*

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cpython/Modules/selectmodule.c at 3.5 · python/cpython · GitHub

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