Modules/selectmodule.c - platform/external/python/cpython3 - Gitiles

 /***********************************************************
 Copyright (c) 2000, BeOpen.com.
 Copyright (c) 1995-2000, Corporation for National Research Initiatives.
 Copyright (c) 1990-1995, Stichting Mathematisch Centrum.
 All rights reserved.

 See the file "Misc/COPYRIGHT" for information on usage and
 redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 ******************************************************************/

 /* 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.
    Under BeOS, we suffer the same dichotomy as Win32; sockets can be anything
    >= 0.
 */

 #include "Python.h"

 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif

 #ifdef __sgi
 /* This is missing from unistd.h */
 extern void bzero();
 #endif

 #ifndef DONT_HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif

 #if defined(PYOS_OS2)
 #include <sys/time.h>
 #include <utils.h>
 #endif

 #ifdef MS_WINDOWS
 #include <winsock.h>
 #else
 #ifdef __BEOS__
 #include <net/socket.h>
 #define SOCKET int
 #else
 #include "myselect.h" /* Also includes mytime.h */
 #define SOCKET int
 #endif
 #endif

 static PyObject *SelectError;

 /* 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(fd2obj)
 	pylist fd2obj[FD_SETSIZE + 3];
 {
 	int i;
 	for (i = 0; i < FD_SETSIZE + 3 && fd2obj[i].sentinel >= 0; i++) {
 		Py_XDECREF(fd2obj[i].obj);
 		fd2obj[i].obj = NULL;
 	}
 	fd2obj[0].sentinel = -1;
 }


 /* returns -1 and sets the Python exception if an error occurred, otherwise
    returns a number >= 0
 */
 static int
 list2set(list, set, fd2obj)
 	PyObject *list;
 	fd_set *set;
 	pylist fd2obj[FD_SETSIZE + 3];
 {
 	int i;
 	int max = -1;
 	int index = 0;
 	int len = PyList_Size(list);
 	PyObject* o = NULL;

 	fd2obj[0].obj = (PyObject*)0;	     /* set list to zero size */
 	FD_ZERO(set);

 	for (i = 0; i < len; i++)  {
 		PyObject *meth;
 		SOCKET v;

 		/* any intervening fileno() calls could decr this refcnt */
 		if (!(o = PyList_GetItem(list, i)))
                     return -1;

 		Py_INCREF(o);

 		if (PyInt_Check(o)) {
 			v = PyInt_AsLong(o);
 		}
 		else if ((meth = PyObject_GetAttrString(o, "fileno")) != NULL)
 		{
 			PyObject *fno = PyEval_CallObject(meth, NULL);
 			Py_DECREF(meth);
 			if (fno == NULL)
 				goto finally;

                         if (!PyInt_Check(fno)) {
 				PyErr_SetString(PyExc_TypeError,
                                        "fileno method returned a non-integer");
 				Py_DECREF(fno);
 				goto finally;
                         }
                         v = PyInt_AsLong(fno);
 			Py_DECREF(fno);
 		}
 		else {
 			PyErr_SetString(PyExc_TypeError,
 			"argument must be an int, or have a fileno() method.");
 			goto finally;
 		}
 #if defined(_MSC_VER)
 		max = 0;		     /* not used for Win32 */
 #else  /* !_MSC_VER */
 		if (v < 0 || v >= FD_SETSIZE) {
 			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;
 	}
 	return max+1;

   finally:
 	Py_XDECREF(o);
 	return -1;
 }

 /* returns NULL and sets the Python exception if an error occurred */
 static PyObject *
 set2list(set, fd2obj)
 	fd_set *set;
 	pylist fd2obj[FD_SETSIZE + 3];
 {
 	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)) {
 #ifndef _MSC_VER
 			if (fd > FD_SETSIZE) {
 				PyErr_SetString(PyExc_SystemError,
 			   "filedescriptor out of range returned in select()");
 				goto finally;
 			}
 #endif
 			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;
 }


 static PyObject *
 select_select(self, args)
 	PyObject *self;
 	PyObject *args;
 {
 #ifdef MS_WINDOWS
 	/* This would be an awful lot of stack space on Windows! */
 	pylist *rfd2obj, *wfd2obj, *efd2obj;
 #else
 	pylist rfd2obj[FD_SETSIZE + 3];
 	pylist wfd2obj[FD_SETSIZE + 3];
 	pylist efd2obj[FD_SETSIZE + 3];
 #endif
 	PyObject *ifdlist, *ofdlist, *efdlist;
 	PyObject *ret = NULL;
 	PyObject *tout = Py_None;
 	fd_set ifdset, ofdset, efdset;
 	double timeout;
 	struct timeval tv, *tvp;
 	long seconds;
 	int imax, omax, emax, max;
 	int n;

 	/* convert arguments */
 	if (!PyArg_ParseTuple(args, "OOO|O:select",
 			      &ifdlist, &ofdlist, &efdlist, &tout))
 		return NULL;

 	if (tout == Py_None)
 		tvp = (struct timeval *)0;
 	else if (!PyArg_Parse(tout, "d", &timeout)) {
 		PyErr_SetString(PyExc_TypeError,
 				"timeout must be a float or None");
 		return NULL;
 	}
 	else {
 		if (timeout > (double)LONG_MAX) {
 			PyErr_SetString(PyExc_OverflowError, "timeout period too long");
 			return NULL;
 		}
 		seconds = (long)timeout;
 		timeout = timeout - (double)seconds;
 		tv.tv_sec = seconds;
 		tv.tv_usec = (long)(timeout*1000000.0);
 		tvp = &tv;
 	}

 	/* sanity check first three arguments */
 	if (!PyList_Check(ifdlist) ||
 	    !PyList_Check(ofdlist) ||
 	    !PyList_Check(efdlist))
 	{
 		PyErr_SetString(PyExc_TypeError,
 				"arguments 1-3 must be lists");
 		return NULL;
 	}

 #ifdef MS_WINDOWS
 	/* Allocate memory for the lists */
 	rfd2obj = PyMem_NEW(pylist, FD_SETSIZE + 3);
 	wfd2obj = PyMem_NEW(pylist, FD_SETSIZE + 3);
 	efd2obj = PyMem_NEW(pylist, FD_SETSIZE + 3);
 	if (rfd2obj == NULL || wfd2obj == NULL || efd2obj == NULL) {
 		if (rfd2obj) PyMem_DEL(rfd2obj);
 		if (wfd2obj) PyMem_DEL(wfd2obj);
 		if (efd2obj) PyMem_DEL(efd2obj);
 		return NULL;
 	}
 #endif
 	/* Convert lists to fd_sets, and get maximum fd number
 	 * propagates the Python exception set in list2set()
 	 */
 	rfd2obj[0].sentinel = -1;
 	wfd2obj[0].sentinel = -1;
 	efd2obj[0].sentinel = -1;
 	if ((imax=list2set(ifdlist, &ifdset, rfd2obj)) < 0)
 		goto finally;
 	if ((omax=list2set(ofdlist, &ofdset, wfd2obj)) < 0)
 		goto finally;
 	if ((emax=list2set(efdlist, &efdset, efd2obj)) < 0)
 		goto finally;
 	max = imax;
 	if (omax > max) max = omax;
 	if (emax > max) max = emax;

 	Py_BEGIN_ALLOW_THREADS
 	n = select(max, &ifdset, &ofdset, &efdset, tvp);
 	Py_END_ALLOW_THREADS

 	if (n < 0) {
 		PyErr_SetFromErrno(SelectError);
 	}
 	else if (n == 0) {
                 /* optimization */
 		ifdlist = PyList_New(0);
 		if (ifdlist) {
 			ret = Py_BuildValue("OOO", ifdlist, ifdlist, ifdlist);
 			Py_DECREF(ifdlist);
 		}
 	}
 	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 = Py_BuildValue("OOO", ifdlist, ofdlist, efdlist);

 		Py_DECREF(ifdlist);
 		Py_DECREF(ofdlist);
 		Py_DECREF(efdlist);
 	}

   finally:
 	reap_obj(rfd2obj);
 	reap_obj(wfd2obj);
 	reap_obj(efd2obj);
 #ifdef MS_WINDOWS
 	PyMem_DEL(rfd2obj);
 	PyMem_DEL(wfd2obj);
 	PyMem_DEL(efd2obj);
 #endif
 	return ret;
 }

 static char 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 lists 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 descriptors.";


 static PyMethodDef select_methods[] = {
     {"select",	select_select, 1, select_doc},
     {0,  	0},			     /* sentinel */
 };

 static char 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.";

 DL_EXPORT(void)
 initselect()
 {
 	PyObject *m, *d;
 	m = Py_InitModule3("select", select_methods, module_doc);
 	d = PyModule_GetDict(m);
 	SelectError = PyErr_NewException("select.error", NULL, NULL);
 	PyDict_SetItemString(d, "error", SelectError);
 }
	/***********************************************************
	Copyright (c) 2000, BeOpen.com.
	Copyright (c) 1995-2000, Corporation for National Research Initiatives.
	Copyright (c) 1990-1995, Stichting Mathematisch Centrum.
	All rights reserved.

	See the file "Misc/COPYRIGHT" for information on usage and
	redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
	******************************************************************/

	/* 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.
	Under BeOS, we suffer the same dichotomy as Win32; sockets can be anything
	>= 0.
	*/

	#include "Python.h"

	#ifdef HAVE_UNISTD_H
	#include <unistd.h>
	#endif

	#ifdef __sgi
	/* This is missing from unistd.h */
	extern void bzero();
	#endif

	#ifndef DONT_HAVE_SYS_TYPES_H
	#include <sys/types.h>
	#endif

	#if defined(PYOS_OS2)
	#include <sys/time.h>
	#include <utils.h>
	#endif

	#ifdef MS_WINDOWS
	#include <winsock.h>
	#else
	#ifdef __BEOS__
	#include <net/socket.h>
	#define SOCKET int
	#else
	#include "myselect.h" /* Also includes mytime.h */
	#define SOCKET int
	#endif
	#endif

	static PyObject *SelectError;

	/* 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(fd2obj)
	pylist fd2obj[FD_SETSIZE + 3];
	{
	int i;
	for (i = 0; i < FD_SETSIZE + 3 && fd2obj[i].sentinel >= 0; i++) {
	Py_XDECREF(fd2obj[i].obj);
	fd2obj[i].obj = NULL;
	}
	fd2obj[0].sentinel = -1;
	}


	/* returns -1 and sets the Python exception if an error occurred, otherwise
	returns a number >= 0
	*/
	static int
	list2set(list, set, fd2obj)
	PyObject *list;
	fd_set *set;
	pylist fd2obj[FD_SETSIZE + 3];
	{
	int i;
	int max = -1;
	int index = 0;
	int len = PyList_Size(list);
	PyObject* o = NULL;

	fd2obj[0].obj = (PyObject)0; / set list to zero size */
	FD_ZERO(set);

	for (i = 0; i < len; i++) {
	PyObject *meth;
	SOCKET v;

	/* any intervening fileno() calls could decr this refcnt */
	if (!(o = PyList_GetItem(list, i)))
	return -1;

	Py_INCREF(o);

	if (PyInt_Check(o)) {
	v = PyInt_AsLong(o);
	}
	else if ((meth = PyObject_GetAttrString(o, "fileno")) != NULL)
	{
	PyObject *fno = PyEval_CallObject(meth, NULL);
	Py_DECREF(meth);
	if (fno == NULL)
	goto finally;

	if (!PyInt_Check(fno)) {
	PyErr_SetString(PyExc_TypeError,
	"fileno method returned a non-integer");
	Py_DECREF(fno);
	goto finally;
	}
	v = PyInt_AsLong(fno);
	Py_DECREF(fno);
	}
	else {
	PyErr_SetString(PyExc_TypeError,
	"argument must be an int, or have a fileno() method.");
	goto finally;
	}
	#if defined(_MSC_VER)
	max = 0; /* not used for Win32 */
	#else /* !_MSC_VER */
	if (v < 0 \|\| v >= FD_SETSIZE) {
	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;
	}
	return max+1;

	finally:
	Py_XDECREF(o);
	return -1;
	}

	/* returns NULL and sets the Python exception if an error occurred */
	static PyObject *
	set2list(set, fd2obj)
	fd_set *set;
	pylist fd2obj[FD_SETSIZE + 3];
	{
	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)) {
	#ifndef _MSC_VER
	if (fd > FD_SETSIZE) {
	PyErr_SetString(PyExc_SystemError,
	"filedescriptor out of range returned in select()");
	goto finally;
	}
	#endif
	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;
	}


	static PyObject *
	select_select(self, args)
	PyObject *self;
	PyObject *args;
	{
	#ifdef MS_WINDOWS
	/* This would be an awful lot of stack space on Windows! */
	pylist rfd2obj, wfd2obj, *efd2obj;
	#else
	pylist rfd2obj[FD_SETSIZE + 3];
	pylist wfd2obj[FD_SETSIZE + 3];
	pylist efd2obj[FD_SETSIZE + 3];
	#endif
	PyObject ifdlist, ofdlist, *efdlist;
	PyObject *ret = NULL;
	PyObject *tout = Py_None;
	fd_set ifdset, ofdset, efdset;
	double timeout;
	struct timeval tv, *tvp;
	long seconds;
	int imax, omax, emax, max;
	int n;

	/* convert arguments */
	if (!PyArg_ParseTuple(args, "OOO\|O:select",
	&ifdlist, &ofdlist, &efdlist, &tout))
	return NULL;

	if (tout == Py_None)
	tvp = (struct timeval *)0;
	else if (!PyArg_Parse(tout, "d", &timeout)) {
	PyErr_SetString(PyExc_TypeError,
	"timeout must be a float or None");
	return NULL;
	}
	else {
	if (timeout > (double)LONG_MAX) {
	PyErr_SetString(PyExc_OverflowError, "timeout period too long");
	return NULL;
	}
	seconds = (long)timeout;
	timeout = timeout - (double)seconds;
	tv.tv_sec = seconds;
	tv.tv_usec = (long)(timeout*1000000.0);
	tvp = &tv;
	}

	/* sanity check first three arguments */
	if (!PyList_Check(ifdlist) \|\|
	!PyList_Check(ofdlist) \|\|
	!PyList_Check(efdlist))
	{
	PyErr_SetString(PyExc_TypeError,
	"arguments 1-3 must be lists");
	return NULL;
	}

	#ifdef MS_WINDOWS
	/* Allocate memory for the lists */
	rfd2obj = PyMem_NEW(pylist, FD_SETSIZE + 3);
	wfd2obj = PyMem_NEW(pylist, FD_SETSIZE + 3);
	efd2obj = PyMem_NEW(pylist, FD_SETSIZE + 3);
	if (rfd2obj == NULL \|\| wfd2obj == NULL \|\| efd2obj == NULL) {
	if (rfd2obj) PyMem_DEL(rfd2obj);
	if (wfd2obj) PyMem_DEL(wfd2obj);
	if (efd2obj) PyMem_DEL(efd2obj);
	return NULL;
	}
	#endif
	/* Convert lists to fd_sets, and get maximum fd number
	* propagates the Python exception set in list2set()
	*/
	rfd2obj[0].sentinel = -1;
	wfd2obj[0].sentinel = -1;
	efd2obj[0].sentinel = -1;
	if ((imax=list2set(ifdlist, &ifdset, rfd2obj)) < 0)
	goto finally;
	if ((omax=list2set(ofdlist, &ofdset, wfd2obj)) < 0)
	goto finally;
	if ((emax=list2set(efdlist, &efdset, efd2obj)) < 0)
	goto finally;
	max = imax;
	if (omax > max) max = omax;
	if (emax > max) max = emax;

	Py_BEGIN_ALLOW_THREADS
	n = select(max, &ifdset, &ofdset, &efdset, tvp);
	Py_END_ALLOW_THREADS

	if (n < 0) {
	PyErr_SetFromErrno(SelectError);
	}
	else if (n == 0) {
	/* optimization */
	ifdlist = PyList_New(0);
	if (ifdlist) {
	ret = Py_BuildValue("OOO", ifdlist, ifdlist, ifdlist);
	Py_DECREF(ifdlist);
	}
	}
	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 = Py_BuildValue("OOO", ifdlist, ofdlist, efdlist);

	Py_DECREF(ifdlist);
	Py_DECREF(ofdlist);
	Py_DECREF(efdlist);
	}

	finally:
	reap_obj(rfd2obj);
	reap_obj(wfd2obj);
	reap_obj(efd2obj);
	#ifdef MS_WINDOWS
	PyMem_DEL(rfd2obj);
	PyMem_DEL(wfd2obj);
	PyMem_DEL(efd2obj);
	#endif
	return ret;
	}

	static char 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 lists 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 descriptors.";


	static PyMethodDef select_methods[] = {
	{"select", select_select, 1, select_doc},
	{0, 0}, /* sentinel */
	};

	static char 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.";

	DL_EXPORT(void)
	initselect()
	{
	PyObject m, d;
	m = Py_InitModule3("select", select_methods, module_doc);
	d = PyModule_GetDict(m);
	SelectError = PyErr_NewException("select.error", NULL, NULL);
	PyDict_SetItemString(d, "error", SelectError);
	}