Fixed exception thrown when in FreeBSD when /proc exists but it's not mounted. Closes #235

scrapy/contrib/memusage.py

@@ -4,7 +4,6 @@ MemoryUsage extension
 See documentation in docs/topics/extensions.rst
 """
 
-import os
 import socket
 from pprint import pformat
 
@@ -18,7 +17,7 @@ from scrapy.exceptions import NotConfigured
 from scrapy.mail import MailSender
 from scrapy.conf import settings
 from scrapy.stats import stats
-from scrapy.utils.memory import get_vmvalue_from_procfs
+from scrapy.utils.memory import get_vmvalue_from_procfs, procfs_supported
 from scrapy.utils.engine import get_engine_status
 
 class MemoryUsage(object):
@@ -26,7 +25,7 @@ class MemoryUsage(object):
     def __init__(self):
         if not settings.getbool('MEMUSAGE_ENABLED'):
             raise NotConfigured
-        if not os.path.exists('/proc'):
+        if not procfs_supported():
             raise NotConfigured
 
         self.warned = False

scrapy/tests/test_utils_memory.py

@@ -1,13 +1,11 @@
-import os
-
 from twisted.trial import unittest
 
-from scrapy.utils.memory import get_vmvalue_from_procfs
+from scrapy.utils.memory import get_vmvalue_from_procfs, procfs_supported
 
 class UtilsMemoryTestCase(unittest.TestCase):
 
     def test_get_vmvalue_from_procfs(self):
-        if not os.path.exists('/proc'):
+        if not procfs_supported():
             raise unittest.SkipTest('/proc filesystem not supported')
         vmsize = get_vmvalue_from_procfs('VmSize')
         vmrss = get_vmvalue_from_procfs('VmRSS')

scrapy/utils/memory.py

@@ -23,3 +23,10 @@ def get_vmvalue_from_procfs(vmkey='VmSize', pid=None):
     # convert Vm value to bytes
     return int(v[1]) * _vmvalue_scale[v[2]]
 
+def procfs_supported():
+    try:
+        open('/proc/%d/status' % os.getpid())
+    except IOError:
+        return False
+    else:
+        return True