Added new process-pool runner based on AMPoule (integrated into Evennia).

This allows e.g. utils.utils.run_async to offload long-running functions
to a completely different subprocess entirely, offering real parallelism.

Implementation is still experimental, notably not all objects can be
transferred safely across the wire; also there is no concept of
updating caches yet - so adding an object from the subprocess side
will not be known in the main thread yet (since caches cannot yet tell
the underlying database has changed).

src/server/server.py

@@ -39,9 +39,6 @@ SERVER_RESTART = os.path.join(settings.GAME_DIR, 'server.restart')
 # module containing hook methods
 SERVER_HOOK_MODULE = mod_import(settings.AT_SERVER_STARTSTOP_MODULE)
 
-# i18n
-from django.utils.translation import ugettext as _
-
 #------------------------------------------------------------
 # Evennia Server settings
 #------------------------------------------------------------
@@ -53,11 +50,25 @@ AMP_ENABLED = True
 AMP_HOST = settings.AMP_HOST
 AMP_PORT = settings.AMP_PORT
 
+PROCPOOL_ENABLED = settings.PROCPOOL_ENABLED
+PROCPOOL_DEBUG = settings.PROCPOOL_DEBUG
+PROCPOOL_MIN_NPROC = settings.PROCPOOL_MIN_NPROC
+PROCPOOL_MAX_NPROC = settings.PROCPOOL_MAX_NPROC
+PROCPOOL_TIMEOUT = settings.PROCPOOL_TIMEOUT
+PROCPOOL_IDLETIME = settings.PROCPOOL_IDLETIME
+PROCPOOL_HOST = settings.PROCPOOL_HOST
+PROCPOOL_PORT = settings.PROCPOOL_PORT
+PROCPOOL_INTERFACE = settings.PROCPOOL_INTERFACE
+PROCPOOL_UID = settings.PROCPOOL_UID
+PROCPOOL_GID = settings.PROCPOOL_GID
+PROCPOOL_DIRECTORY = settings.PROCPOOL_DIRECTORY
+
 # server-channel mappings
 IMC2_ENABLED = settings.IMC2_ENABLED
 IRC_ENABLED = settings.IRC_ENABLED
 RSS_ENABLED = settings.RSS_ENABLED
 
+
 #------------------------------------------------------------
 # Evennia Main Server object
 #------------------------------------------------------------
@@ -208,7 +219,10 @@ class Evennia(object):
         Outputs server startup info to the terminal.
         """
         print ' %(servername)s Server (%(version)s) started.' % {'servername': SERVERNAME, 'version': VERSION}
-        print '  amp (Portal): %s' % AMP_PORT
+        print '  amp (to Portal): %s' % AMP_PORT
+        if PROCPOOL_ENABLED:
+            print '  amp (Process Pool): %s' % PROCPOOL_PORT
+
 
     def set_restart_mode(self, mode=None):
         """
@@ -319,6 +333,49 @@ if AMP_ENABLED:
     amp_service.setName("EvenniaPortal")
     EVENNIA.services.addService(amp_service)
 
+# The ampoule twisted extension manages asynchronous process pools
+# via an AMP port. It can be used to offload expensive operations
+# to another process asynchronously.
+
+if PROCPOOL_ENABLED:
+
+    from src.utils.ampoule import main as ampoule_main
+    from src.utils.ampoule import service as ampoule_service
+    from src.utils.ampoule import pool as ampoule_pool
+    from src.utils.ampoule.main import BOOTSTRAP as _BOOTSTRAP
+    from src.server.procpool import ProcPoolChild
+
+    # for some reason absolute paths don't work here, only relative ones.
+    apackages = ("twisted",
+                 os.path.join(os.pardir, "src", "utils", "ampoule"),
+                 os.path.join(os.pardir, "ev"),
+                 os.path.join(os.pardir))
+    aenv = {"DJANGO_SETTINGS_MODULE":"settings",
+            "DATABASE_NAME":settings.DATABASES.get("default", {}).get("NAME") or settings.DATABASE_NAME}
+    if PROCPOOL_DEBUG:
+        _BOOTSTRAP = _BOOTSTRAP % "log.startLogging(sys.stderr)"
+    else:
+        _BOOTSTRAP = _BOOTSTRAP % ""
+
+    procpool_starter = ampoule_main.ProcessStarter(packages=apackages,
+                                                   env=aenv,
+                                                   path=PROCPOOL_DIRECTORY,
+                                                   uid=PROCPOOL_UID,
+                                                   gid=PROCPOOL_GID,
+                                                   bootstrap=_BOOTSTRAP,
+                                                   childReactor=os.name == 'nt' and "select" or "epoll")
+    procpool = ampoule_pool.ProcessPool(name="ProcPool",
+                                        min=PROCPOOL_MIN_NPROC,
+                                        max=PROCPOOL_MAX_NPROC,
+                                        recycleAfter=500,
+                                        ampChild=ProcPoolChild,
+                                        starter=procpool_starter)
+    procpool_service = ampoule_service.AMPouleService(procpool,
+                                                      ProcPoolChild,
+                                                      PROCPOOL_PORT,
+                                                      PROCPOOL_INTERFACE)
+    procpool_service.setName("ProcPool")
+    EVENNIA.services.addService(procpool_service)
 
 if IRC_ENABLED: