refactored the way locks work in combox.siloComboxSilo.

	modified:   combox/cbox.py
	modified:   combox/events.py
	modified:   combox/silo.py
	modified:   tests/events_test.py
	modified:   tests/silo_test.py

3 files changed, 20 insertions, 11 deletions

diff --git a/combox/cbox.py b/combox/cbox.py
index 4424274..add5883 100644
--- a/combox/cbox.py
+++ b/combox/cbox.py
@@ -25,6 +25,7 @@ import yaml
 from argparse import ArgumentParser
 from os import path
 from sys import exit
+from threading import Lock
 from watchdog.observers import Observer
 
 from combox.config import config_cb
@@ -39,7 +40,8 @@ def run_cb(config):
     Runs combox.
     """
     c_path = path.abspath(config['combox_dir'])
-    event_handler = ComboxDirMonitor(config)
+    db_lock = Lock()
+    event_handler = ComboxDirMonitor(config, db_lock)
 
     observer = Observer()
     observer.schedule(event_handler, c_path, recursive=True)
diff --git a/combox/events.py b/combox/events.py
index fa47ceb..3ef4386 100644
--- a/combox/events.py
+++ b/combox/events.py
@@ -20,6 +20,7 @@ import os
 import logging
 
 from os import path
+from threading import Lock
 
 from watchdog.events import LoggingEventHandler
 
@@ -37,7 +38,7 @@ class ComboxDirMonitor(LoggingEventHandler):
 
     """
 
-    def __init__(self, config):
+    def __init__(self, config, dblock):
         """
         config: a dictinary which contains combox configuration.
         """
@@ -48,7 +49,7 @@ class ComboxDirMonitor(LoggingEventHandler):
                             datefmt='%Y-%m-%d %H:%M:%S')
 
         self.config = config
-        self.silo = ComboxSilo(self.config)
+        self.silo = ComboxSilo(self.config, dblock)
 
         self.housekeep()
 
@@ -57,7 +58,7 @@ class ComboxDirMonitor(LoggingEventHandler):
         """
         Re-reads the silo from disk.
         """
-        self.silo = ComboxSilo(self.config)
+        self.silo.reload()
 
 
     def housekeep(self):
@@ -186,7 +187,7 @@ class NodeDirMonitor(LoggingEventHandler):
 
     """
 
-    def __init__(self, config):
+    def __init__(self, config, dblock):
         """
         config: a dictinary which contains combox configuration.
         """
@@ -197,14 +198,14 @@ class NodeDirMonitor(LoggingEventHandler):
                             datefmt='%Y-%m-%d %H:%M:%S')
 
         self.config = config
-        self.silo = ComboxSilo(self.config)
+        self.silo = ComboxSilo(self.config, dblock)
 
 
     def silo_update(self):
         """
         Re-reads the silo from disk.
         """
-        self.silo = ComboxSilo(self.config)
+        self.silo.reload()
 
 
     def shardp(self, path):
diff --git a/combox/silo.py b/combox/silo.py
index 55345c9..f391d2e 100644
--- a/combox/silo.py
+++ b/combox/silo.py
@@ -30,14 +30,14 @@ class ComboxSilo(object):
     """
 
 
-    def __init__(self, config):
+    def __init__(self, config, lock):
         """config: a dictinary which contains combox configuration.
 
         """
         self.config = config
 
-        silo = path.join(config['silo_dir'], 'silo.db')
-        self.db = pickledb.load(silo, True)
+        self.silo_path = path.join(config['silo_dir'], 'silo.db')
+        self.db = pickledb.load(self.silo_path, True)
 
         ## things we need for housekeep the node directory.
         self.node_dicts = ['shard_created', 'shard_modified', 'shard_moved',
@@ -48,7 +48,13 @@ class ComboxSilo(object):
             if not self.db.get(ndict):
                 self.db.dcreate(ndict)
 
-        self.lock = Lock()
+        self.lock = lock
+
+
+    def reload(self):
+        """Re-loads the DB from disk."""
+        with self.lock:
+            self.db = pickledb.load(self.silo_path, True)
 
 
     def update(self, filep):