diff -r 85fc1e5dea79 -r 67ecea2d9b67 iro/tests/testloglock.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/iro/tests/testloglock.py	Fri Nov 18 22:36:50 2011 +0100
@@ -0,0 +1,98 @@
+
+import unittest
+import os
+import tempfile
+import signal
+import threading
+import time
+
+class testLogLock(unittest.TestCase):
+    def test_ThreadingAndLocks(self):
+        #create a thread, have that thread grab a lock, and sleep.
+        fd, file = tempfile.mkstemp('.nonlog')
+        _lock = threading.RLock()
+        os.close(fd)
+        def locker():
+            os.write(fd, 'Thread acquiring lock\n')
+            _lock.acquire()
+            os.write(fd, 'Thread acquired lock\n')
+            time.sleep(0.4)
+            os.write(fd, 'Thread releasing lock\n')
+            _lock.release()
+            os.write(fd, 'Thread released lock\n')
+
+        #Then in the main thread, throw a signal to self
+        def handleSignal(sigNum, frame):
+            os.write(fd, 'Main Thread acquiring lock\n')
+            lock = False
+            endtime = time.time() + 1.0
+            while not lock:
+                lock = _lock.acquire(blocking=0)
+                time.sleep(0.01)
+                if time.time() > endtime:
+                    break
+            if not lock:
+                os.write(fd, 'Main Thread could not acquire lock\n')
+                return
+            os.write(fd, 'Main Thread acquired lock\n')
+            os.write(fd, 'Main Thread releasing lock\n')
+            _lock.release()
+            os.write(fd, 'Main Thread released lock\n')
+
+        sighndlr = signal.signal(signal.SIGUSR1, handleSignal)
+        try:
+            fd = os.open(file, os.O_SYNC | os.O_WRONLY | os.O_CREAT)
+            thread = threading.Thread(target=locker)
+            thread.start()
+            time.sleep(0.1)
+            os.kill(os.getpid(), signal.SIGUSR1)
+            thread.join()
+
+            #check the results
+            os.close(fd)
+            fileconts = open(file, 'r').read()
+            self.assertTrue('Main Thread released lock' in fileconts)
+            self.assertEqual(fileconts,
+                '''Thread acquiring lock
+Thread acquired lock
+Main Thread acquiring lock
+Thread releasing lock
+Thread released lock
+Main Thread acquired lock
+Main Thread releasing lock
+Main Thread released lock
+''')
+
+            #Now try after acquiring the lock from the main thread
+            fd = os.open(file, os.O_SYNC | os.O_WRONLY | os.O_CREAT)
+            _lock.acquire()
+            thread = threading.Thread(target=locker)
+            thread.start()
+            time.sleep(0.1)
+            os.kill(os.getpid(), signal.SIGUSR1)
+            _lock.release()
+            thread.join()
+            os.close(fd)
+            fileconts = open(file, 'r').read()
+            self.assertEqual(fileconts,
+                '''Thread acquiring lock
+Main Thread acquiring lock
+Main Thread acquired lock
+Main Thread releasing lock
+Main Thread released lock
+Thread acquired lock
+Thread releasing lock
+Thread released lock
+''')
+
+        finally:
+            signal.signal(signal.SIGUSR1, sighndlr)
+            try:
+                os.close(fd)
+            except OSError:
+                pass
+            try:
+                os.unlink(file)
+            except OSError:
+                pass
+