Changeset 5e3d889 for fedd/federation/synch_store.py

Timestamp:

Feb 27, 2010 1:20:56 PM (14 years ago)

Author:

Ted Faber <faber@…>

Branches:

axis_example, compt_changes, info-ops, master, version-3.01, version-3.02

Children:

f017447

Parents:

7dc855c

Message:

Documentation and remove the redundant, unused key attribute from the synch_value

File:

• fedd/federation/synch_store.py (modified) (5 diffs)

fedd/federation/synch_store.py

@@ -10 +10 @@
     deadlock threads waiting for the assignment.
     """
+
+    # Thrown if a key is assigned more than once
     class CollisionError(Exception): pass
+
+    # Thrown if a non-existant key is deleted
     class BadDeletionError(Exception): pass
 
+    # A value in the dict.  Each has its own condition (and lock) for threads
+    # to wait on.
     class synch_value:
-        def __init__(self, key, value=None):
-            self.key = key
+        # The synch_value constructor. 
+        def __init__(self, value=None):
             self.value = value
             self.condition = Condition()
 
+        # Debugging representation
         def __str__(self):
-            return "key %s value %s cond %s" % \
-                (self.key, self.value, self.condition)
+            return "value %s cond %s" % (self.value, self.condition)
 
+    # The synch_store constructor.  Note that the store has its own lock for
+    # serializing additions to the dict.
     def __init__(self):
         self.main_lock = Lock()
         self.values = { }
 
+    # Set the value in the dict.  If threads are waiting, wake them.
     def set_value(self, key, value):
         self.main_lock.acquire()
@@ -41 +50 @@
                 raise synch_store.CollisionError("%s already set" % key)
         else:
-            self.values[key] = synch_store.synch_value(key, value)
+            self.values[key] = synch_store.synch_value(value)
             self.main_lock.release()
 
+    # Ask for the value.  If wait is true, wait until the key is set, if it is
+    # not already.  If wait is false, poll.
     def get_value(self, key, wait=True):
         self.main_lock.acquire()
         if not self.values.has_key(key):
-            self.values[key] = synch_store.synch_value(key)
+            self.values[key] = synch_store.synch_value()
         v = self.values[key]
         v.condition.acquire()
@@ -59 +70 @@
         return rv
 
+    # Remove the key from the shared store.  If the key is not present or has
+    # never been set, fail.  Otherwise, wake any waiting threads (there
+    # shouldn't be any) and remove the value and key from the store.
     def del_value(self, key):
         self.main_lock.acquire()
@@ -75 +89 @@
             raise synch_store.BadDeletionError("%s does not exist yet" % key)
 
+    # A debugging representation
     def __str__(self):
         rv = ""
@@ -80 +95 @@
         for k, v in self.values.items():
             self.values[k].condition.acquire()
-            rv += "%s: %s" % ( k, str(self.values[k]))
+            rv += "%s: %s\n" % ( k, str(self.values[k]))
             self.values[k].condition.release()
         self.main_lock.release()