Refresh pool of other processes

When a process change the list of activated modules, the others must refresh
their pool. We do that by just stopping the pool for that database, the next
request will load the new pool.

issue8988
review302861002

CHANGELOG

@@ -1,3 +1,4 @@
+* Refresh pool of other processes
 * Add clear_all method to Cache
 * Support Genshi element directives in HTML editor
 * Add firstline tool

trytond/cache.py

@@ -16,6 +16,7 @@ from sql.functions import CurrentTimestamp, Function
 
 from trytond import backend
 from trytond.config import config
+from trytond.pool import Pool
 from trytond.transaction import Transaction
 from trytond.tools import resolve, grouped_slice
 
@@ -43,6 +44,15 @@ def freeze(o):
         return o
 
 
+def _get_modules(cursor):
+    ir_module = Table('ir_module')
+    cursor.execute(*ir_module.select(
+            ir_module.name,
+            where=ir_module.state.in_(
+                ['activated', 'to upgrade', 'to remove'])))
+    return {m for m, in cursor}
+
+
 class BaseCache(object):
     _instances = {}
 
@@ -195,6 +205,7 @@ class MemoryCache(BaseCache):
                 timestamps = {}
                 for timestamp, name in cursor.fetchall():
                     timestamps[name] = timestamp
+                modules = _get_modules(cursor)
         finally:
             database.put_connection(connection)
         for name, timestamp in timestamps.items():
@@ -205,6 +216,7 @@ class MemoryCache(BaseCache):
             inst_timestamp = inst._timestamp.get(dbname)
             if not inst_timestamp or timestamp > inst_timestamp:
                 inst._clear(dbname, timestamp)
+        Pool(dbname).refresh(modules)
         cls._clean_last = datetime.now()
 
     def sync_since(self, value):
@@ -291,6 +303,21 @@ class MemoryCache(BaseCache):
             inst._database_cache.pop(dbname, None)
             inst._transaction_lower.pop(dbname, None)
 
+    @classmethod
+    def refresh_pool(cls, transaction):
+        database = transaction.database
+        dbname = database.name
+        if not _clear_timeout and database.has_channel():
+            database = backend.Database(dbname)
+            conn = database.get_connection()
+            try:
+                cursor = conn.cursor()
+                cursor.execute(
+                    'NOTIFY "%s", %%s' % cls._channel, ('refresh pool',))
+                conn.commit()
+            finally:
+                database.put_connection(conn)
+
     @classmethod
     def _listen(cls, dbname):
         database = backend.Database(dbname)
@@ -313,7 +340,9 @@ class MemoryCache(BaseCache):
                 conn.poll()
                 while conn.notifies:
                     notification = conn.notifies.pop()
-                    if notification.payload:
+                    if notification.payload == 'refresh pool':
+                        Pool(dbname).refresh(_get_modules(cursor))
+                    elif notification.payload:
                         reset = json.loads(notification.payload)
                         for name in reset:
                             inst = cls._instances[name]

trytond/ir/module.py

@@ -5,6 +5,7 @@ from functools import wraps
 
 from sql.operators import NotIn
 
+from trytond.cache import Cache
 from trytond.exceptions import UserError
 from trytond.i18n import gettext
 from trytond.model import ModelView, ModelSQL, fields, Unique, sequence_ordered
@@ -557,7 +558,8 @@ class ModuleActivateUpgrade(Wizard):
         pool = Pool()
         Module = pool.get('ir.module')
         Lang = pool.get('ir.lang')
-        with Transaction().new_transaction():
+        transaction = Transaction()
+        with transaction.new_transaction():
             modules = Module.search([
                 ('state', 'in', ['to upgrade', 'to remove', 'to activate']),
                 ])
@@ -568,6 +570,7 @@ class ModuleActivateUpgrade(Wizard):
             lang = [x.code for x in langs]
         if update:
             pool.init(update=update, lang=lang)
+            Cache.refresh_pool(transaction)
         return 'done'
 
 

trytond/modules/__init__.py

@@ -302,6 +302,7 @@ def load_module_graph(graph, pool, update=None, lang=None):
 
         # Ensure cache is clear for other instances
         Cache.clear_all()
+        Cache.refresh_pool(transaction)
     logger.info('all modules loaded')
 
 

trytond/pool.py

@@ -113,12 +113,12 @@ class Pool(object):
         with cls._lock:
             if database_name in cls._instances:
                 del cls._instances[database_name]
-        lock = cls._locks.get(database_name)
-        if not lock:
-            return
-        with lock:
-            if database_name in cls._pool:
-                del cls._pool[database_name]
+            lock = cls._locks.get(database_name)
+            if not lock:
+                return
+            with lock:
+                if database_name in cls._pool:
+                    del cls._pool[database_name]
 
     @classmethod
     def database_list(cls):
@@ -271,6 +271,10 @@ class Pool(object):
                             cls.__name__, (mixin, cls), {'__slots__': ()})
                         self.add(cls, type=type_)
 
+    def refresh(self, modules):
+        if set(self._modules) != modules:
+            self.stop(self.database_name)
+
 
 def isregisteredby(obj, module, type_='model'):
     pool = Pool()