MTP: Add tests for mem leaks

src/calibre/devices/mtp/test.py

@@ -7,7 +7,7 @@ __license__   = 'GPL v3'
 __copyright__ = '2012, Kovid Goyal <kovid at kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import unittest
+import unittest, gc
 
 from calibre.constants import iswindows, islinux
 from calibre.utils.icu import lower
@@ -78,13 +78,52 @@ class TestDeviceInteraction(unittest.TestCase):
             with self.assertRaises(ValueError):
                 self.dev.create_folder(root_file[0], 'sub-folder')
 
+    def measure_memory_usage(self, repetitions, func, *args, **kwargs):
+        from calibre.utils.mem import memory
+        gc.disable()
+        try:
+            start_mem = memory()
+            for i in xrange(repetitions):
+                func(*args, **kwargs)
+            for i in xrange(3): gc.collect()
+            end_mem = memory()
+        finally:
+            gc.enable()
+        return end_mem - start_mem
+
     def test_memory_leaks(self):
+        ''' Test for memory leaks in the C modules '''
         if not (iswindows or islinux):
             self.skipTest('Can only test for leaks on windows and linux')
-        from calibre.utils.mem import memory
+
+        # Test device scanning
+        used_by_one = self.measure_memory_usage(1,
+                self.dev.detect_managed_devices, self.scanner.devices,
+                force_refresh=True)
+
+        used_by_many = self.measure_memory_usage(1000,
+                self.dev.detect_managed_devices, self.scanner.devices,
+                force_refresh=True)
+
+        self.assertTrue(used_by_many <= used_by_one,
+                msg='Memory consumption during device scan: for one: %g for many:%g'%
+                (used_by_one, used_by_many))
+
+        # Test get_filesystem
+        used_by_one = self.measure_memory_usage(1,
+                self.dev.dev.get_filesystem, self.storage.object_id)
+
+        used_by_many = self.measure_memory_usage(5,
+                self.dev.dev.get_filesystem, self.storage.object_id)
+
+        self.assertTrue(used_by_many <= used_by_one,
+                msg='Memory consumption during get_filesystem: for one: %g for many:%g'%
+                (used_by_one, used_by_many))
 
 def tests():
-    return unittest.TestLoader().loadTestsFromTestCase(TestDeviceInteraction)
+    tl = unittest.TestLoader()
+    return tl.loadTestsFromName('test.TestDeviceInteraction.test_memory_leaks')
+    return tl.loadTestsFromTestCase(TestDeviceInteraction)
 
 def run():
     unittest.TextTestRunner(verbosity=2).run(tests())

src/calibre/devices/mtp/unix/libmtp.c

@@ -14,7 +14,7 @@
 
 #include "devices.h"
 
-// Macros and utilities
+// Macros and utilities {{{
 static PyObject *MTPError = NULL;
 
 #define ENSURE_DEV(rval) \