/* 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.

*/

#ifndef Py_BUILD_CORE_BUILTIN

# define Py_BUILD_CORE_MODULE 1

#endif

#if defined(HAVE_POLL_H) && !defined(_GNU_SOURCE)

# define _GNU_SOURCE

#endif

#include "Python.h"

#include "pycore_fileutils.h" // _Py_set_inheritable()

#include "pycore_time.h" // _PyTime_FromSecondsObject()

#include <stdbool.h>

#include <stddef.h> // offsetof()

#ifndef MS_WINDOWS

# include <unistd.h> // close()

#endif

#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

# ifndef WIN32_LEAN_AND_MEAN

# define WIN32_LEAN_AND_MEAN

# endif

# include <winsock2.h>

#else

# define SOCKET int

#endif

// WASI SDK 16 does not have POLLPRIO, define as no-op

#if defined(__wasi__) && !defined(POLLPRI)

# define POLLPRI 0

#endif

#ifdef HAVE_KQUEUE

// Linked list to track kqueue objects with an open fd, so

// that we can invalidate them at fork;

typedef struct _kqueue_list_item {

struct kqueue_queue_Object *obj;

struct _kqueue_list_item *next;

} _kqueue_list_item, *_kqueue_list;

#endif

typedef struct {

PyObject *close;

PyTypeObject *poll_Type;

PyTypeObject *devpoll_Type;

PyTypeObject *pyEpoll_Type;

#ifdef HAVE_KQUEUE

PyTypeObject *kqueue_event_Type;

PyTypeObject *kqueue_queue_Type;

_kqueue_list kqueue_open_list;

bool kqueue_tracking_initialized;

#endif

} _selectstate;

static struct PyModuleDef selectmodule;

static inline _selectstate*

get_select_state(PyObject *module)

{

void *state = PyModule_GetState(module);

assert(state != NULL);

return (_selectstate *)state;

}

#define _selectstate_by_type(type) get_select_state(PyType_GetModule(type))

/*[clinic input]

module select

class select.poll "pollObject *" "_selectstate_by_type(type)->poll_Type"

class select.devpoll "devpollObject *" "_selectstate_by_type(type)->devpoll_Type"

class select.epoll "pyEpoll_Object *" "_selectstate_by_type(type)->pyEpoll_Type"

class select.kqueue "kqueue_queue_Object *" "_selectstate_by_type(type)->kqueue_queue_Type"

[clinic start generated code]*/

/*[clinic end generated code: output=da39a3ee5e6b4b0d input=8072de35824aa327]*/

/* 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])

{

unsigned int i;

for (i = 0; i < (unsigned int)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;

unsigned 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 >= (unsigned int)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 */

/*[clinic input]

select.select

rlist: object

wlist: object

xlist: object

timeout as timeout_obj: object = None

/

Wait until one or more file descriptors are ready for some kind of I/O.

The first three arguments are iterables of file descriptors to be waited

for:

rlist -- wait until ready for reading

wlist -- wait until ready for writing

xlist -- wait for an "exceptional condition"

If only one kind of condition is required, pass [] for the other lists.

A file descriptor is either a socket or file object, or a small integer

gotten from a fileno() method call on one of those.

The optional 4th argument specifies a timeout in seconds; it may be

a floating-point number to specify fractions of seconds. If it is absent

or None, the call will never time out.

The return value is a tuple of three lists corresponding to the first

three arguments; each contains the subset of the corresponding file

descriptors that are ready.

*** IMPORTANT NOTICE ***

On Windows, only sockets are supported; on Unix, all file

descriptors can be used.

[clinic start generated code]*/

static PyObject *

select_select_impl(PyObject *module, PyObject *rlist, PyObject *wlist,

PyObject *xlist, PyObject *timeout_obj)

/*[clinic end generated code: output=2b3cfa824f7ae4cf input=34a2c2075ca9830e]*/

{

#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 *ret = NULL;

fd_set ifdset, ofdset, efdset;

struct timeval tv, *tvp;

int imax, omax, emax, max;

int n;

PyTime_t timeout, deadline = 0;

if (timeout_obj == Py_None)

tvp = (struct timeval *)NULL;

else {

if (_PyTime_FromSecondsObject(&timeout, timeout_obj,

_PyTime_ROUND_TIMEOUT) < 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_TIMEOUT) == -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_Free(rfd2obj);

if (wfd2obj) PyMem_Free(wfd2obj);

if (efd2obj) PyMem_Free(efd2obj);

return PyErr_NoMemory();

}

#endif /* SELECT_USES_HEAP */

/* Convert iterables 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(rlist, &ifdset, rfd2obj)) < 0)

goto finally;

if ((omax = seq2set(wlist, &ofdset, wfd2obj)) < 0)

goto finally;

if ((emax = seq2set(xlist, &efdset, efd2obj)) < 0)

goto finally;

max = imax;

if (omax > max) max = omax;

if (emax > max) max = emax;

if (tvp) {

deadline = _PyDeadline_Init(timeout);

}

do {

Py_BEGIN_ALLOW_THREADS

errno = 0;

n = select(

max,

imax ? &ifdset : NULL,

omax ? &ofdset : NULL,

emax ? &efdset : NULL,

tvp);

Py_END_ALLOW_THREADS

if (errno != EINTR)

break;

/* select() was interrupted by a signal */

if (PyErr_CheckSignals())

goto finally;

if (tvp) {

timeout = _PyDeadline_Get(deadline);

if (timeout < 0) {

/* bpo-35310: lists were unmodified -- clear them explicitly */

FD_ZERO(&ifdset);

FD_ZERO(&ofdset);

FD_ZERO(&efdset);

n = 0;

break;

}

_PyTime_AsTimeval_clamp(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?

*/

rlist = set2list(&ifdset, rfd2obj);

wlist = set2list(&ofdset, wfd2obj);

xlist = set2list(&efdset, efd2obj);

if (PyErr_Occurred())

ret = NULL;

else

ret = PyTuple_Pack(3, rlist, wlist, xlist);

Py_XDECREF(rlist);

Py_XDECREF(wlist);

Py_XDECREF(xlist);

}

finally:

reap_obj(rfd2obj);

reap_obj(wfd2obj);

reap_obj(efd2obj);

#ifdef SELECT_USES_HEAP

PyMem_Free(rfd2obj);

PyMem_Free(wfd2obj);

PyMem_Free(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;

#define pollObject_CAST(op) ((pollObject *)(op))

/* 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_GET_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;

}

/*[clinic input]

@critical_section

select.poll.register

fd: fildes

either an integer, or an object with a fileno() method returning an int

eventmask: unsigned_short(c_default="POLLIN | POLLPRI | POLLOUT") = select.POLLIN | select.POLLPRI | select.POLLOUT

an optional bitmask describing the type of events to check for

/

Register a file descriptor with the polling object.

[clinic start generated code]*/

static PyObject *

select_poll_register_impl(pollObject *self, int fd, unsigned short eventmask)

/*[clinic end generated code: output=0dc7173c800a4a65 input=c475e029ce6c2830]*/

{

PyObject *key, *value;

int err;

/* 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(eventmask);

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_RETURN_NONE;

}

/*[clinic input]

@critical_section

select.poll.modify

fd: fildes

either an integer, or an object with a fileno() method returning

an int

eventmask: unsigned_short

a bitmask describing the type of events to check for

/

Modify an already registered file descriptor.

[clinic start generated code]*/

static PyObject *

select_poll_modify_impl(pollObject *self, int fd, unsigned short eventmask)

/*[clinic end generated code: output=1a7b88bf079eff17 input=38c9db5346711872]*/

{

PyObject *key, *value;

int err;

/* Modify registered fd */

key = PyLong_FromLong(fd);

if (key == NULL)

return NULL;

err = PyDict_Contains(self->dict, key);

if (err < 0) {

Py_DECREF(key);

return NULL;

}

if (err == 0) {

errno = ENOENT;

PyErr_SetFromErrno(PyExc_OSError);

Py_DECREF(key);

return NULL;

}

value = PyLong_FromLong(eventmask);

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_RETURN_NONE;

}

/*[clinic input]

@critical_section

select.poll.unregister

fd: fildes

/

Remove a file descriptor being tracked by the polling object.

[clinic start generated code]*/

static PyObject *

select_poll_unregister_impl(pollObject *self, int fd)

/*[clinic end generated code: output=8c9f42e75e7d291b input=ae6315d7f5243704]*/

{

PyObject *key;

/* 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_RETURN_NONE;

}

/*[clinic input]

@critical_section

select.poll.poll

timeout as timeout_obj: object = None

The maximum time to wait in milliseconds, or else None (or a negative

value) to wait indefinitely.

/

Polls the set of registered file descriptors.

Returns a list containing any descriptors that have events or errors

to report, as a list of (fd, event) 2-tuples.

[clinic start generated code]*/

static PyObject *

select_poll_poll_impl(pollObject *self, PyObject *timeout_obj)

/*[clinic end generated code: output=876e837d193ed7e4 input=e0a9c0aa283de8c8]*/

{

PyObject *result_list = NULL;

int poll_result, i, j;

PyObject *value = NULL, *num = NULL;

PyTime_t timeout = -1, ms = -1, deadline = 0;

int async_err = 0;

if (timeout_obj != Py_None) {

if (_PyTime_FromMillisecondsObject(&timeout, timeout_obj,

_PyTime_ROUND_TIMEOUT) < 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_TIMEOUT);

if (ms < INT_MIN || ms > INT_MAX) {

PyErr_SetString(PyExc_OverflowError, "timeout is too large");

return NULL;

}

if (timeout >= 0) {

deadline = _PyDeadline_Init(timeout);

}

}

/* On some OSes, typically BSD-based ones, the timeout parameter of the

poll() syscall, when negative, must be exactly INFTIM, where defined,

or -1. See issue 31334. */

if (ms < 0) {

#ifdef INFTIM

ms = INFTIM;

#else

ms = -1;

#endif

}

/* 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 = _PyDeadline_Get(deadline);

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);

PyList_SET_ITEM(result_list, j, value);

i++;

}

return result_list;

error:

Py_DECREF(result_list);

return NULL;

}

static pollObject *

newPollObject(PyObject *module)

{

pollObject *self;

self = PyObject_New(pollObject, get_select_state(module)->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(PyObject *op)

{

pollObject *self = pollObject_CAST(op);

PyTypeObject *type = Py_TYPE(self);

if (self->ufds != NULL) {

PyMem_Free(self->ufds);

}

Py_XDECREF(self->dict);

PyObject_Free(self);

Py_DECREF(type);

}

#ifdef HAVE_SYS_DEVPOLL_H

static PyMethodDef devpoll_methods[];

typedef struct {

PyObject_HEAD

int fd_devpoll;

int max_n_fds;

int n_fds;

struct pollfd *fds;

} devpollObject;

#define devpollObject_CAST(op) ((devpollObject *)(op))

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 written 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 https://github.com/python/cpython/issues/50646.

*/

PyErr_Format(PyExc_OSError, "failed to write all pollfds. "

"Please, report at https://github.com/python/cpython/issues/. "

"Data to report: Size tried: %d, actual size written: %d.",

size, n);

return -1;

}

return 0;

}

static PyObject *

internal_devpoll_register(devpollObject *self, int fd,

unsigned short events, int remove)

{

if (self->fd_devpoll < 0)

return devpoll_err_closed();

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;

}

/*[clinic input]

@critical_section

select.devpoll.register

fd: fildes

either an integer, or an object with a fileno() method returning

an int

eventmask: unsigned_short(c_default="POLLIN | POLLPRI | POLLOUT") = select.POLLIN | select.POLLPRI | select.POLLOUT

an optional bitmask describing the type of events to check for

/

Register a file descriptor with the polling object.

[clinic start generated code]*/

static PyObject *

select_devpoll_register_impl(devpollObject *self, int fd,

unsigned short eventmask)

/*[clinic end generated code: output=6e07fe8b74abba0c input=8d48bd2653a61c42]*/

{

return internal_devpoll_register(self, fd, eventmask, 0);

}

/*[clinic input]

@critical_section

select.devpoll.modify

fd: fildes

either an integer, or an object with a fileno() method returning

an int

eventmask: unsigned_short(c_default="POLLIN | POLLPRI | POLLOUT") = select.POLLIN | select.POLLPRI | select.POLLOUT

an optional bitmask describing the type of events to check for

/

Modify a possible already registered file descriptor.

[clinic start generated code]*/

static PyObject *

select_devpoll_modify_impl(devpollObject *self, int fd,

unsigned short eventmask)

/*[clinic end generated code: output=bc2e6d23aaff98b4 input=773b37e9abca2460]*/

{

return internal_devpoll_register(self, fd, eventmask, 1);

}

/*[clinic input]

@critical_section

select.devpoll.unregister

fd: fildes

/

Remove a file descriptor being tracked by the polling object.

[clinic start generated code]*/

static PyObject *

select_devpoll_unregister_impl(devpollObject *self, int fd)

/*[clinic end generated code: output=95519ffa0c7d43fe input=6052d368368d4d05]*/

{

if (self->fd_devpoll < 0)

return devpoll_err_closed();

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;

}

/*[clinic input]

@critical_section

select.devpoll.poll

timeout as timeout_obj: object = None

The maximum time to wait in milliseconds, or else None (or

a negative value) to wait indefinitely.

/

Polls the set of registered file descriptors.

Returns a list containing any descriptors that have events or errors

to report, as a list of (fd, event) 2-tuples.

[clinic start generated code]*/

static PyObject *

select_devpoll_poll_impl(devpollObject *self, PyObject *timeout_obj)

/*[clinic end generated code: output=2654e5457cca0b3c input=9e1672658d728539]*/

{

struct dvpoll dvp;

PyObject *result_list = NULL;

int poll_result, i;

PyObject *value, *num1, *num2;

PyTime_t timeout, ms, deadline = 0;

if (self->fd_devpoll < 0)

return devpoll_err_closed();

/* Check values for timeout */

if (timeout_obj == Py_None) {

timeout = -1;

ms = -1;

}

else {

if (_PyTime_FromMillisecondsObject(&timeout, timeout_obj,

_PyTime_ROUND_TIMEOUT) < 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_TIMEOUT);

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 = _PyDeadline_Init(timeout);

}