commit 20d7f9d13cbc183d33a129324137b06d2aaeb313 Author: Damian Johnson atagar@torproject.org Date: Mon Sep 1 15:43:39 2014 -0700

Adding proc.get_file_descriptors_used

Just a little helper for getting the number of file descriptors a process is using. --- docs/change_log.rst | 1 + stem/util/proc.py | 38 +++++++++++++++++++++++++++++++++----- test/unit/util/proc.py | 31 +++++++++++++++++++++++++++++++ 3 files changed, 65 insertions(+), 5 deletions(-)

diff --git a/docs/change_log.rst b/docs/change_log.rst index 2b6964c..24e39f0 100644 --- a/docs/change_log.rst +++ b/docs/change_log.rst @@ -54,6 +54,7 @@ The following are only available within Stem's `git repository * Added support for directories to :func:`stem.util.conf.Config.load`. * Changed :func:`stem.util.conf.uses_settings` to only provide a 'config' keyword arument if the decorated function would accept it. * Added :func:`stem.util.str_tools.crop` + * Added :func:`stem.util.proc.get_file_descriptors_used`

* **Interpreter**

diff --git a/stem/util/proc.py b/stem/util/proc.py index 62b7a5e..f9b2a59 100644 --- a/stem/util/proc.py +++ b/stem/util/proc.py @@ -26,6 +26,7 @@ future, use them at your own risk.** get_uid - provides the user id a process is running under get_memory_usage - provides the memory usage of a process get_stats - queries statistics about a process + get_file_descriptors_used - number of file descriptors used by a process get_connections - provides the connections made by a process

.. data:: Stat (enum) @@ -292,6 +293,31 @@ def get_stats(pid, *stat_types): return tuple(results)

+def get_file_descriptors_used(pid): + """ + Provides the number of file descriptors currently being used by a process. + + :param int pid: process id of the process to be queried + + :returns: **int** of the number of file descriptors used + + :raises: **IOError** if it can't be determined + """ + + try: + pid = int(pid) + + if pid < 0: + raise IOError("Process pids can't be negative: %s" % pid) + except (ValueError, TypeError): + raise IOError('Process pid was non-numeric: %s' % pid) + + try: + return len(os.listdir('/proc/%i/fd' % pid)) + except Exception as exc: + raise IOError("Unable to check number of file descriptors used: %s" % exc) + + def get_connections(pid): """ Queries connection related information from the proc contents. This provides @@ -307,11 +333,13 @@ def get_connections(pid): :raises: **IOError** if it can't be determined """

- if isinstance(pid, str): - try: - pid = int(pid) - except ValueError: - raise IOError('Process pid was non-numeric: %s' % pid) + try: + pid = int(pid) + + if pid < 0: + raise IOError("Process pids can't be negative: %s" % pid) + except (ValueError, TypeError): + raise IOError('Process pid was non-numeric: %s' % pid)

if pid == 0: return [] diff --git a/test/unit/util/proc.py b/test/unit/util/proc.py index c682853..1786a99 100644 --- a/test/unit/util/proc.py +++ b/test/unit/util/proc.py @@ -144,6 +144,37 @@ class TestProc(unittest.TestCase): self.assertEquals(response, proc.get_stats(0, *args))

@patch('os.listdir') + def test_get_file_descriptors_used(self, listdir_mock): + """ + Tests the get_file_descriptors_used function. + """ + + # check that we reject bad pids + + for arg in (None, -100, 'hello',): + self.assertRaises(IOError, proc.get_file_descriptors_used, arg) + + # when proc directory doesn't exist + + error_msg = "OSError: [Errno 2] No such file or directory: '/proc/2118/fd'" + listdir_mock.side_effect = OSError(error_msg) + + try: + proc.get_file_descriptors_used(2118) + self.fail("We should raise when listdir() fails") + except IOError as exc: + expected = "Unable to check number of file descriptors used: %s" % error_msg + self.assertEqual(expected, str(exc)) + + # successful calls + + listdir_mock.return_value = ['0', '1', '2', '3', '4', '5'] + listdir_mock.side_effect = None + + self.assertEqual(6, proc.get_file_descriptors_used(2118)) + self.assertEqual(6, proc.get_file_descriptors_used('2118')) + + @patch('os.listdir') @patch('os.readlink') @patch('stem.util.proc.open', create = True) def test_get_connections(self, open_mock, readlink_mock, listdir_mock):