[tor-commits] [stem/master] Correcting issues with pid_by_name()

[atagar at torproject.org]

commit 738d4f54fb2559236b810d2ca3ca6b1e0eb5edc1
Author: Damian Johnson <atagar at torproject.org>
Date:   Tue Feb 17 09:34:58 2015 -0800

    Correcting issues with pid_by_name()
    
    This has quite a few bits of weirdness...
    
      * Our comment says call() doesn't work but then uses it.
    
      * Our comment says the command might or might not end with '.exe' but then we
        always check for that. Sounds wrong but opting for what the code does and
        just dropping the mismatching comment.
    
      * We checked for '.exe' anywhere in the string rather than just the end.
    
      * We checked to see if the netstat command existed to see if we could run
        tasklist.
    
      * Unlike the other checks we raised an exception here rather than passing
        through when unable to determine the pid.
    
      * Regex handling was a bit more verbose than it needed to be.
    
      * We didn't actually use GET_PID_BY_NAME_TASKLIST.
---
 stem/util/system.py       |   31 ++++++++-----------------------
 test/integ/util/system.py |    6 ++----
 2 files changed, 10 insertions(+), 27 deletions(-)

diff --git a/stem/util/system.py b/stem/util/system.py
index efe8663..9ee8ad6 100644
--- a/stem/util/system.py
+++ b/stem/util/system.py
@@ -47,10 +47,10 @@ import ctypes.util
 import mimetypes
 import os
 import platform
+import re
 import subprocess
 import tarfile
 import time
-import re
 
 import stem.util.proc
 import stem.util.str_tools
@@ -79,7 +79,6 @@ GET_PID_BY_NAME_PIDOF = 'pidof %s'
 GET_PID_BY_NAME_PS_LINUX = 'ps -o pid -C %s'
 GET_PID_BY_NAME_PS_BSD = 'ps axc'
 GET_PID_BY_NAME_LSOF = 'lsof -tc %s'
-GET_PID_BY_NAME_TASKLIST = 'tasklist | findstr %s'
 GET_PID_BY_PORT_NETSTAT = 'netstat -npltu'
 GET_PID_BY_PORT_SOCKSTAT = 'sockstat -4l -P tcp -p %s'
 GET_PID_BY_PORT_LSOF = 'lsof -wnP -iTCP -sTCP:LISTEN'
@@ -438,48 +437,34 @@ def pid_by_name(process_name, multiple = False):
       except ValueError:
         pass
 
-  # Calling and Parsing tasklist command on Windows (Because call method doesn't work properly with it)
-  # Process name may or may not include .exe
-  if is_available('netstat -ano') and is_windows():
-
-    if process_name.find(".exe") == -1:
+  if is_available('tasklist') and is_windows():
+    if not process_name.endswith('.exe'):
       process_name = process_name + '.exe'
 
-    command = GET_PID_BY_NAME_TASKLIST % process_name
     process_ids = []
 
-    try:
-      results = stem.util.system.call('tasklist')
-      tasklist_regex_str = '^\s*' + process_name + '\s+(?P<pid>[0-9]*)'
-      tasklist_regex = re.compile(tasklist_regex_str)
+    results = stem.util.system.call('tasklist', None)
 
-      if not results:
-        raise IOError("No results found for tasklist")
+    if results:
+      tasklist_regex = re.compile('^\s*%s\s+(?P<pid>[0-9]*)' % process_name)
 
       for line in results:
         match = tasklist_regex.search(line)
+
         if match:
-          attr = match.groupdict()
-          id = int(attr['pid'])
-          process_ids.append(id)
+          process_ids.append(int(match.group('pid')))
 
       if multiple:
         return process_ids
       elif len(process_ids) > 0:
         return process_ids[0]
 
-    except OSError as exc:
-      log.debug("failed to query '%s': %s" % (command, exc))
-      raise IOError("Unable to query '%s': %s" % (command, exc))
-
   log.debug("failed to resolve a pid for '%s'" % process_name)
   return [] if multiple else None
 
 
 def pid_by_port(port):
-
   """
-
   Attempts to determine the process id for a process with the given port,
   using...
 
diff --git a/test/integ/util/system.py b/test/integ/util/system.py
index aa18f45..e06b569 100644
--- a/test/integ/util/system.py
+++ b/test/integ/util/system.py
@@ -221,7 +221,6 @@ class TestSystem(unittest.TestCase):
     Tests the pid_by_name function with a tasklist response.
     """
 
-    runner = test.runner.get_runner()
     if self._is_extra_tor_running():
       test.runner.skip(self, '(multiple tor instances)')
       return
@@ -229,9 +228,8 @@ class TestSystem(unittest.TestCase):
       test.runner.skip(self, '(tasklist unavailable)')
       return
 
-    tor_pid = test.runner.get_runner().get_pid()
-    tor_cmd = test.runner.get_runner().get_tor_command(True)
-    self.assertEqual(tor_pid, stem.util.system.pid_by_name(tor_cmd))
+    runner = test.runner.get_runner()
+    self.assertEqual(runner.get_pid(), stem.util.system.pid_by_name(runner.get_tor_command(True)))
 
   def test_pid_by_port(self):
     """