mirror of
				https://github.com/python/cpython.git
				synced 2025-11-04 11:49:12 +00:00 
			
		
		
		
	
		
			
				
	
	
		
			391 lines
		
	
	
	
		
			9.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			391 lines
		
	
	
	
		
			9.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/***********************************************************
 | 
						|
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
 | 
						|
The Netherlands.
 | 
						|
 | 
						|
                        All Rights Reserved
 | 
						|
 | 
						|
Permission to use, copy, modify, and distribute this software and its
 | 
						|
documentation for any purpose and without fee is hereby granted,
 | 
						|
provided that the above copyright notice appear in all copies and that
 | 
						|
both that copyright notice and this permission notice appear in
 | 
						|
supporting documentation, and that the names of Stichting Mathematisch
 | 
						|
Centrum or CWI or Corporation for National Research Initiatives or
 | 
						|
CNRI not be used in advertising or publicity pertaining to
 | 
						|
distribution of the software without specific, written prior
 | 
						|
permission.
 | 
						|
 | 
						|
While CWI is the initial source for this software, a modified version
 | 
						|
is made available by the Corporation for National Research Initiatives
 | 
						|
(CNRI) at the Internet address ftp://ftp.python.org.
 | 
						|
 | 
						|
STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
 | 
						|
REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
 | 
						|
MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
 | 
						|
CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
 | 
						|
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 | 
						|
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 | 
						|
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 | 
						|
PERFORMANCE OF THIS SOFTWARE.
 | 
						|
 | 
						|
******************************************************************/
 | 
						|
 | 
						|
/* 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;
 | 
						|
	int 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 {
 | 
						|
		seconds = (int)timeout;
 | 
						|
		timeout = timeout - (double)seconds;
 | 
						|
		tv.tv_sec = seconds;
 | 
						|
		tv.tv_usec = (int)(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) {
 | 
						|
		PyMem_XDEL(rfd2obj);
 | 
						|
		PyMem_XDEL(wfd2obj);
 | 
						|
		PyMem_XDEL(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);
 | 
						|
}
 |