mirror of
https://github.com/python/cpython.git
synced 2025-09-26 18:29:57 +00:00
Reworked to eliminate all potential memory problems, including
deletion of object from list argument during callout to fileno().
This commit is contained in:
Barry Warsaw
parent
32616fbee6
commit
c1cb360683
1 changed files with 110 additions and 73 deletions
|
|
@ -57,11 +57,26 @@ extern void bzero();
|
|||
|
||||
static PyObject *SelectError;
|
||||
|
||||
typedef struct { /* list of Python objects and their file descriptor */
|
||||
PyObject *obj;
|
||||
/* 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
|
||||
*/
|
||||
|
|
@ -71,67 +86,76 @@ list2set(list, set, fd2obj)
|
|||
fd_set *set;
|
||||
pylist fd2obj[FD_SETSIZE + 3];
|
||||
{
|
||||
int i, len, index, max = -1;
|
||||
PyObject *o, *fno;
|
||||
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;
|
||||
|
||||
index = 0;
|
||||
fd2obj[0].obj = (PyObject*)0; /* set list to zero size */
|
||||
|
||||
FD_ZERO(set);
|
||||
len = PyList_Size(list);
|
||||
for (i=0; i<len; i++) {
|
||||
/* any intervening fileno() calls could decr this refcnt */
|
||||
o = PyList_GetItem(list, i);
|
||||
Py_INCREF(o);
|
||||
|
||||
if (PyInt_Check(o)) {
|
||||
v = PyInt_AsLong(o);
|
||||
}
|
||||
else if ((meth = PyObject_GetAttrString(o, "fileno")) != NULL)
|
||||
{
|
||||
fno = PyEval_CallObject(meth, NULL);
|
||||
PyObject *fno = PyEval_CallObject(meth, NULL);
|
||||
Py_DECREF(meth);
|
||||
if (fno == NULL)
|
||||
return -1;
|
||||
goto finally;
|
||||
|
||||
if (!PyInt_Check(fno)) {
|
||||
PyErr_SetString(PyExc_TypeError,
|
||||
"fileno method returned a non-integer");
|
||||
Py_DECREF(fno);
|
||||
return -1;
|
||||
goto finally;
|
||||
}
|
||||
v = PyInt_AsLong(fno);
|
||||
Py_DECREF(fno);
|
||||
}
|
||||
else {
|
||||
PyErr_SetString(PyExc_TypeError,
|
||||
"argument must be an int, or have a fileno() method."
|
||||
);
|
||||
return -1;
|
||||
"argument must be an int, or have a fileno() method.");
|
||||
goto finally;
|
||||
}
|
||||
#ifdef _MSC_VER
|
||||
max = 0; /* not used for Win32 */
|
||||
#else
|
||||
#else /* !_MSC_VER */
|
||||
if (v < 0 || v >= FD_SETSIZE) {
|
||||
PyErr_SetString(
|
||||
PyExc_ValueError,
|
||||
PyErr_SetString(PyExc_ValueError,
|
||||
"filedescriptor out of range in select()");
|
||||
return -1;
|
||||
goto finally;
|
||||
}
|
||||
if (v > max)
|
||||
max = v;
|
||||
#endif
|
||||
#endif /* _MSC_VER */
|
||||
FD_SET(v, set);
|
||||
|
||||
/* add object and its file descriptor to the list */
|
||||
if (index >= FD_SETSIZE) {
|
||||
PyErr_SetString(
|
||||
PyExc_ValueError,
|
||||
PyErr_SetString(PyExc_ValueError,
|
||||
"too many file descriptors in select()");
|
||||
return -1;
|
||||
goto finally;
|
||||
}
|
||||
fd2obj[index].obj = o;
|
||||
fd2obj[index].fd = v;
|
||||
fd2obj[++index].obj = (PyObject *)0; /* sentinel */
|
||||
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 */
|
||||
|
|
@ -140,41 +164,45 @@ set2list(set, fd2obj)
|
|||
fd_set *set;
|
||||
pylist fd2obj[FD_SETSIZE + 3];
|
||||
{
|
||||
int j, num=0;
|
||||
int i, j, count=0;
|
||||
PyObject *list, *o;
|
||||
SOCKET fd;
|
||||
|
||||
for (j=0; fd2obj[j].obj; j++)
|
||||
for (j = 0; fd2obj[j].sentinel >= 0; j++) {
|
||||
if (FD_ISSET(fd2obj[j].fd, set))
|
||||
num++;
|
||||
|
||||
list = PyList_New(num);
|
||||
count++;
|
||||
}
|
||||
list = PyList_New(count);
|
||||
if (!list)
|
||||
return NULL;
|
||||
|
||||
num = 0;
|
||||
for (j=0; fd2obj[j].obj; j++) {
|
||||
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()");
|
||||
return NULL;
|
||||
goto finally;
|
||||
}
|
||||
#endif
|
||||
o = fd2obj[j].obj;
|
||||
Py_INCREF(o);
|
||||
if (PyList_SetItem(list, num, o) < 0) {
|
||||
Py_DECREF(list);
|
||||
return NULL;
|
||||
}
|
||||
num++;
|
||||
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;
|
||||
|
|
@ -184,7 +212,7 @@ select_select(self, args)
|
|||
pylist wfd2obj[FD_SETSIZE + 3];
|
||||
pylist efd2obj[FD_SETSIZE + 3];
|
||||
PyObject *ifdlist, *ofdlist, *efdlist;
|
||||
PyObject *ret;
|
||||
PyObject *ret = NULL;
|
||||
PyObject *tout = Py_None;
|
||||
fd_set ifdset, ofdset, efdset;
|
||||
double timeout;
|
||||
|
|
@ -200,9 +228,11 @@ select_select(self, args)
|
|||
|
||||
if (tout == Py_None)
|
||||
tvp = (struct timeval *)0;
|
||||
else if (!PyArg_Parse(tout, "d;timeout must be float or None",
|
||||
&timeout))
|
||||
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;
|
||||
|
|
@ -224,12 +254,15 @@ select_select(self, args)
|
|||
/* 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)
|
||||
return NULL;
|
||||
goto finally;
|
||||
if ((omax=list2set(ofdlist, &ofdset, wfd2obj)) < 0)
|
||||
return NULL;
|
||||
goto finally;
|
||||
if ((emax=list2set(efdlist, &efdset, efd2obj)) < 0)
|
||||
return NULL;
|
||||
goto finally;
|
||||
max = imax;
|
||||
if (omax > max) max = omax;
|
||||
if (emax > max) max = emax;
|
||||
|
|
@ -240,21 +273,19 @@ select_select(self, args)
|
|||
|
||||
if (n < 0) {
|
||||
PyErr_SetFromErrno(SelectError);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if (n == 0) { /* Speedup hack */
|
||||
else if (n == 0) {
|
||||
/* optimization */
|
||||
ifdlist = PyList_New(0);
|
||||
if (!ifdlist)
|
||||
return NULL;
|
||||
if (ifdlist) {
|
||||
ret = Py_BuildValue("OOO", ifdlist, ifdlist, ifdlist);
|
||||
Py_XDECREF(ifdlist);
|
||||
return ret;
|
||||
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?
|
||||
convenient to test for this after all three calls... but
|
||||
is that acceptable?
|
||||
*/
|
||||
ifdlist = set2list(&ifdset, rfd2obj);
|
||||
ofdlist = set2list(&ofdset, wfd2obj);
|
||||
|
|
@ -267,6 +298,12 @@ select_select(self, args)
|
|||
Py_DECREF(ifdlist);
|
||||
Py_DECREF(ofdlist);
|
||||
Py_DECREF(efdlist);
|
||||
}
|
||||
|
||||
finally:
|
||||
reap_obj(rfd2obj);
|
||||
reap_obj(wfd2obj);
|
||||
reap_obj(efd2obj);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue