Issue #16595: Add prlimit() to resource module

prlimit() is a Linux specific command that combines setrlimit, getrlimit and can set the limit
of other processes.
This commit is contained in:
Christian Heimes 2013-10-22 11:21:54 +02:00
parent 6fc79bf813
commit b7bd5df809
8 changed files with 169 additions and 26 deletions

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@ -74,6 +74,27 @@ this module for those platforms.
``setrlimit`` may also raise :exc:`error` if the underlying system call
fails.
.. function:: prlimit(pid, resource[, limits])
Combines :func:`setrlimit` and :func:`getrlimit` in one function and
supports to get and set the resources limits of an arbitrary process. If
*pid* is 0, then the call applies to the current process. *resource* and
*limits* have the same meaning as in :func:`setrlimit`, except that
*limits* is optional.
When *limits* is not given the function returns the *resource* limit of the
process *pid*. When *limits* is given the *resource* limit of the process is
set and the former resource limit is returned.
Raises :exc:`ProcessLookupError` when *pid* can't be found and
:exc:`PermissionError` when the user doesn't have ``CAP_SYS_RESOURCE`` for
the process.
Availability: Linux (glibc 2.13+)
.. versionadded:: 3.4
These symbols define resources whose consumption can be controlled using the
:func:`setrlimit` and :func:`getrlimit` functions described below. The values of
these symbols are exactly the constants used by C programs.

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@ -438,6 +438,12 @@ The :mod:`pprint` module now supports *compact* mode for formatting long
sequences (:issue:`19132`).
resource
--------
New :func:`resource.prlimit` function and Linux specific constants.
(Contributed by Christian Heimes in :issue:`16595` and :issue:`19324`.)
smtplib
-------

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@ -139,6 +139,18 @@ class ResourceTest(unittest.TestCase):
self.assertIsInstance(resource.RLIMIT_SIGPENDING, int)
@unittest.skipUnless(hasattr(resource, 'prlimit'), 'no prlimit')
def test_prlimit(self):
self.assertRaises(TypeError, resource.prlimit)
self.assertRaises(PermissionError, resource.prlimit,
1, resource.RLIMIT_AS)
self.assertRaises(ProcessLookupError, resource.prlimit,
-1, resource.RLIMIT_AS)
self.assertEqual(resource.prlimit(0, resource.RLIMIT_AS), (-1, -1))
self.assertEqual(resource.prlimit(0, resource.RLIMIT_AS, (-1, -1)),
(-1, -1))
def test_main(verbose=None):
support.run_unittest(ResourceTest)

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@ -19,6 +19,8 @@ Core and Builtins
Library
-------
- Issue #16595: Add prlimit() to resource module.
- Issue #19324: Expose Linux-specific constants in resource module.
- Issue #17400: ipaddress should make it easy to identify rfc6598 addresses.

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@ -106,6 +106,44 @@ resource_getrusage(PyObject *self, PyObject *args)
return result;
}
static int
py2rlimit(PyObject *curobj, PyObject *maxobj, struct rlimit *rl_out)
{
#if !defined(HAVE_LARGEFILE_SUPPORT)
rl_out->rlim_cur = PyLong_AsLong(curobj);
if (rl_out->rlim_cur == (rlim_t)-1 && PyErr_Occurred())
return -1;
rl_out->rlim_max = PyLong_AsLong(maxobj);
if (rl_out->rlim_max == (rlim_t)-1 && PyErr_Occurred())
return -1;
#else
/* The limits are probably bigger than a long */
rl_out->rlim_cur = PyLong_AsLongLong(curobj);
if (rl_out->rlim_cur == (rlim_t)-1 && PyErr_Occurred())
return -1;
rl_out->rlim_max = PyLong_AsLongLong(maxobj);
if (rl_out->rlim_max == (rlim_t)-1 && PyErr_Occurred())
return -1;
#endif
rl_out->rlim_cur = rl_out->rlim_cur & RLIM_INFINITY;
rl_out->rlim_max = rl_out->rlim_max & RLIM_INFINITY;
return 0;
}
static PyObject*
rlimit2py(struct rlimit rl)
{
#if defined(HAVE_LONG_LONG)
if (sizeof(rl.rlim_cur) > sizeof(long)) {
return Py_BuildValue("LL",
(PY_LONG_LONG) rl.rlim_cur,
(PY_LONG_LONG) rl.rlim_max);
}
#endif
return Py_BuildValue("ll", (long) rl.rlim_cur, (long) rl.rlim_max);
}
static PyObject *
resource_getrlimit(PyObject *self, PyObject *args)
@ -126,15 +164,7 @@ resource_getrlimit(PyObject *self, PyObject *args)
PyErr_SetFromErrno(PyExc_OSError);
return NULL;
}
#if defined(HAVE_LONG_LONG)
if (sizeof(rl.rlim_cur) > sizeof(long)) {
return Py_BuildValue("LL",
(PY_LONG_LONG) rl.rlim_cur,
(PY_LONG_LONG) rl.rlim_max);
}
#endif
return Py_BuildValue("ll", (long) rl.rlim_cur, (long) rl.rlim_max);
return rlimit2py(rl);
}
static PyObject *
@ -166,25 +196,10 @@ resource_setrlimit(PyObject *self, PyObject *args)
curobj = PyTuple_GET_ITEM(limits, 0);
maxobj = PyTuple_GET_ITEM(limits, 1);
#if !defined(HAVE_LARGEFILE_SUPPORT)
rl.rlim_cur = PyLong_AsLong(curobj);
if (rl.rlim_cur == (rlim_t)-1 && PyErr_Occurred())
if (py2rlimit(curobj, maxobj, &rl) < 0) {
goto error;
rl.rlim_max = PyLong_AsLong(maxobj);
if (rl.rlim_max == (rlim_t)-1 && PyErr_Occurred())
goto error;
#else
/* The limits are probably bigger than a long */
rl.rlim_cur = PyLong_AsLongLong(curobj);
if (rl.rlim_cur == (rlim_t)-1 && PyErr_Occurred())
goto error;
rl.rlim_max = PyLong_AsLongLong(maxobj);
if (rl.rlim_max == (rlim_t)-1 && PyErr_Occurred())
goto error;
#endif
}
rl.rlim_cur = rl.rlim_cur & RLIM_INFINITY;
rl.rlim_max = rl.rlim_max & RLIM_INFINITY;
if (setrlimit(resource, &rl) == -1) {
if (errno == EINVAL)
PyErr_SetString(PyExc_ValueError,
@ -205,6 +220,48 @@ resource_setrlimit(PyObject *self, PyObject *args)
return NULL;
}
#ifdef HAVE_PRLIMIT
static PyObject *
resource_prlimit(PyObject *self, PyObject *args)
{
struct rlimit old_limit, new_limit;
int resource, retval;
pid_t pid;
PyObject *curobj=NULL, *maxobj=NULL;
if (!PyArg_ParseTuple(args, _Py_PARSE_PID "i|(OO):prlimit",
&pid, &resource, &curobj, &maxobj))
return NULL;
if (resource < 0 || resource >= RLIM_NLIMITS) {
PyErr_SetString(PyExc_ValueError,
"invalid resource specified");
return NULL;
}
if (curobj != NULL) {
if (py2rlimit(curobj, maxobj, &new_limit) < 0) {
return NULL;
}
retval = prlimit(pid, resource, &new_limit, &old_limit);
}
else {
retval = prlimit(pid, resource, NULL, &old_limit);
}
if (retval == -1) {
if (errno == EINVAL) {
PyErr_SetString(PyExc_ValueError,
"current limit exceeds maximum limit");
} else {
PyErr_SetFromErrno(PyExc_OSError);
}
return NULL;
}
return rlimit2py(old_limit);
}
#endif /* HAVE_PRLIMIT */
static PyObject *
resource_getpagesize(PyObject *self, PyObject *unused)
{
@ -229,6 +286,9 @@ static struct PyMethodDef
resource_methods[] = {
{"getrusage", resource_getrusage, METH_VARARGS},
{"getrlimit", resource_getrlimit, METH_VARARGS},
#ifdef HAVE_PRLIMIT
{"prlimit", resource_prlimit, METH_VARARGS},
#endif
{"setrlimit", resource_setrlimit, METH_VARARGS},
{"getpagesize", resource_getpagesize, METH_NOARGS},
{NULL, NULL} /* sentinel */

29
configure vendored
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@ -10601,6 +10601,35 @@ $as_echo "no" >&6; }
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for prlimit" >&5
$as_echo_n "checking for prlimit... " >&6; }
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
#include <sys/time.h>
#include <sys/resource.h>
int
main ()
{
void *x=prlimit
;
return 0;
}
_ACEOF
if ac_fn_c_try_compile "$LINENO"; then :
$as_echo "#define HAVE_PRLIMIT 1" >>confdefs.h
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
$as_echo "yes" >&6; }
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
# On some systems (eg. FreeBSD 5), we would find a definition of the
# functions ctermid_r, setgroups in the library, but no prototype
# (e.g. because we use _XOPEN_SOURCE). See whether we can take their

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@ -2927,6 +2927,16 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
AC_MSG_RESULT(yes)],
[AC_MSG_RESULT(no)
])
AC_MSG_CHECKING(for prlimit)
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <sys/time.h>
#include <sys/resource.h>
]], [[void *x=prlimit]])],
[AC_DEFINE(HAVE_PRLIMIT, 1, Define if you have the 'prlimit' functions.)
AC_MSG_RESULT(yes)],
[AC_MSG_RESULT(no)
])
# On some systems (eg. FreeBSD 5), we would find a definition of the
# functions ctermid_r, setgroups in the library, but no prototype
# (e.g. because we use _XOPEN_SOURCE). See whether we can take their

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@ -627,6 +627,9 @@
/* Define to 1 if you have the `pread' function. */
#undef HAVE_PREAD
/* Define if you have the 'prlimit' functions. */
#undef HAVE_PRLIMIT
/* Define to 1 if you have the <process.h> header file. */
#undef HAVE_PROCESS_H