Issue #6397: Support '/dev/poll' polling objects in select module, under Solaris & derivatives.
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index 6071144..5d5e772 100644
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -7,6 +7,14 @@
#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.
@@ -648,6 +656,339 @@
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 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;
+
+ Py_BEGIN_ALLOW_THREADS
+ n = write(self->fd_devpoll, self->fds, size);
+ Py_END_ALLOW_THREADS
+
+ if (n == -1 ) {
+ PyErr_SetFromErrno(PyExc_IOError);
+ 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, events = POLLIN | POLLPRI | POLLOUT;
+
+ if (!PyArg_ParseTuple(args, "O|i:register", &o, &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 = 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;
+
+ 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, *tout = NULL;
+ int poll_result, i;
+ long timeout;
+ PyObject *value, *num1, *num2;
+
+ if (!PyArg_UnpackTuple(args, "poll", 0, 1, &tout)) {
+ return NULL;
+ }
+
+ /* Check values for timeout */
+ if (tout == NULL || tout == Py_None)
+ timeout = -1;
+ else if (!PyNumber_Check(tout)) {
+ PyErr_SetString(PyExc_TypeError,
+ "timeout must be an integer or None");
+ return NULL;
+ }
+ else {
+ tout = PyNumber_Long(tout);
+ if (!tout)
+ return NULL;
+ timeout = PyLong_AsLong(tout);
+ Py_DECREF(tout);
+ if (timeout == -1 && PyErr_Occurred())
+ return NULL;
+ }
+
+ if ((timeout < -1) || (timeout > INT_MAX)) {
+ PyErr_SetString(PyExc_OverflowError,
+ "timeout is out of range");
+ return NULL;
+ }
+
+ if (devpoll_flush(self))
+ return NULL;
+
+ dvp.dp_fds = self->fds;
+ dvp.dp_nfds = self->max_n_fds;
+ dvp.dp_timeout = timeout;
+
+ /* call devpoll() */
+ Py_BEGIN_ALLOW_THREADS
+ poll_result = ioctl(self->fd_devpoll, DP_POLL, &dvp);
+ Py_END_ALLOW_THREADS
+
+ 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;
+ else {
+ 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 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},
+ {NULL, NULL} /* sentinel */
+};
+
+static devpollObject *
+newDevPollObject(void)
+{
+ devpollObject *self;
+ int fd_devpoll, limit_result;
+ struct pollfd *fds;
+ struct rlimit limit;
+
+ Py_BEGIN_ALLOW_THREADS
+ /*
+ ** 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)
+ fd_devpoll = open("/dev/poll", O_RDWR);
+ Py_END_ALLOW_THREADS
+
+ if (limit_result == -1) {
+ PyErr_SetFromErrno(PyExc_OSError);
+ return NULL;
+ }
+ if (fd_devpoll == -1) {
+ PyErr_SetFromErrnoWithFilename(PyExc_IOError, "/dev/poll");
+ 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)
+{
+ Py_BEGIN_ALLOW_THREADS
+ close(self->fd_devpoll);
+ Py_END_ALLOW_THREADS
+
+ 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*/
+};
+#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.");
@@ -658,6 +999,19 @@
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
@@ -1715,6 +2069,11 @@
};
#endif /* HAVE_KQUEUE */
+
+
+
+
+
/* ************************************************************************ */
PyDoc_STRVAR(select_doc,
@@ -1746,6 +2105,9 @@
#ifdef HAVE_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 */
};
@@ -1768,6 +2130,9 @@
NULL
};
+
+
+
PyMODINIT_FUNC
PyInit_select(void)
{
@@ -1824,6 +2189,11 @@
}
#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)