wip

django_q/process_manager.py

@@ -0,0 +1,75 @@
+from abc import ABC
+from django_q.conf import Conf, logger
+from django_q.humanhash import humanize
+import uuid
+from django_q.conf import Conf
+import enum
+from django import db
+from typing import Callable
+from django.utils.translation import gettext_lazy as _
+import multiprocessing
+from multiprocessing import Process, Value
+
+class ProcessManager(ABC):
+    class Status(enum.IntEnum):
+        IDLE = 1
+        BUSY = 2
+        DONE = 3
+        RECYCLE = 4
+
+    target = None
+    status = Value("i", Status.IDLE.value)
+
+    def get_target(self) -> Callable:
+        if self.target is None:
+            raise ValueError("Process must have target specified")
+        return self.target
+
+    def __init__(self):
+        self.process = self.spawn_process()
+        self.name = humanize(uuid.uuid4().hex)
+
+    def spawn_process(self) -> Process:
+        self.manager_pipe, process_pipe = multiprocessing.Pipe(duplex=True)
+        p = Process(target=self.get_target(), args=(self.status, process_pipe))
+        p.start()
+        return p
+
+    def reincarnate_process(self):
+        # kill connections before killing the process
+        logger.critical(_("reincarnated worker %(name)s after death") % {"name": self.process.name})
+        if not Conf.SYNC:
+            db.connections.close_all()
+        self.process.kill()
+        self.process = self.spawn_process()
+        self.mark_idle()
+
+    @property
+    def has_results(self):
+        # poll puller pipe for new tasks
+        return self.manager_pipe.poll()
+
+    def get_result(self):
+        # get the puller pipe task object back from the worker
+        return self.manager_pipe.recv()
+
+    @property
+    def is_alive(self):
+        # get the puller status
+        return self.process.is_alive()
+
+    @property
+    def is_done(self):
+        return self.status.value == self.Status.DONE.value
+
+    @property
+    def is_idle(self):
+        return self.status.value == self.Status.IDLE.value
+
+    @property
+    def is_recycle(self):
+        # worker needs to be recycled/reincarnated
+        return self.status.value == self.Status.RECYCLE.value
+
+    def mark_idle(self):
+        self.status.value = self.Status.IDLE.value