Do not start threads before the end of the evaluation of trytond.application

When uwsgi forks workers it can happen that python execute the code from one of
the launched thread (eg: the cache listener or trytond-status). In that case
python will keep executing the thread and never switch to the main thread. Thus
preventing to listen for incoming connections.

Closes #12758

trytond/trytond/cache.py

@@ -151,7 +151,7 @@ class MemoryCache(BaseCache):
     A key value LRU cache with size limit.
     """
     _reset = WeakKeyDictionary()
-    _clean_last = dt.datetime.now()
+    _clean_last = None
     _default_lower = Transaction.monotonic_time()
     _listener = {}
     _listener_lock = defaultdict(threading.Lock)
@@ -228,6 +228,10 @@ class MemoryCache(BaseCache):
 
     @classmethod
     def sync(cls, transaction):
+        if cls._clean_last is None:
+            cls._clean_last = dt.datetime.now()
+            return
+
         database = transaction.database
         dbname = database.name
         if not _clear_timeout and database.has_channel():

trytond/trytond/config.py

@@ -6,10 +6,6 @@ import os
 import urllib.parse
 from getpass import getuser
 
-import __main__ as main
-
-from . import status
-
 __all__ = ['config', 'get_hostname', 'get_port', 'split_netloc',
     'parse_listen', 'parse_uri']
 logger = logging.getLogger(__name__)
@@ -169,6 +165,3 @@ class TrytonConfigParser(configparser.ConfigParser):
 
 
 config = TrytonConfigParser()
-
-if os.path.basename(getattr(main, '__file__', '')) != 'trytond-stat':
-    status.start(config.get('database', 'path'))

trytond/trytond/status.py

@@ -10,6 +10,8 @@ import time
 from collections import namedtuple
 from contextlib import contextmanager
 
+from trytond.config import config
+
 status = dict()
 logger = logging.getLogger(__name__)
 address = 'trytond-stat.socket'
@@ -17,13 +19,12 @@ address = 'trytond-stat.socket'
 Process = namedtuple('Process', ['start_time', 'request'])
 
 _PID = None
-_PATH = None
 _LOCK = threading.Lock()
 
 
 @contextmanager
 def processing(request):
-    start(_PATH)  # check if running thread
+    start()  # check if running thread
     process = Process(time.perf_counter(), request)
     status[id(process)] = process
     try:
@@ -74,17 +75,17 @@ def dumper(path):
             time.sleep(60)
 
 
-def start(path):
-    global _PID, _PATH
+def start():
+    global _PID
     if not hasattr(socket, 'AF_UNIX'):
         return
-    if _PID != os.getpid() and path:  # Quick test without lock
+    if _PID != os.getpid():  # Quick test without lock
         with _LOCK:
             if _PID != os.getpid():
+                path = config.get('database', 'path')
                 threading.Thread(
                     target=dumper, args=(path,), daemon=True).start()
                 _PID = os.getpid()
-                _PATH = path
 
 
 def listen(path, callback=None):