Add new task state support

trains/backend_interface/task/development/stop_signal.py

@@ -1,5 +1,5 @@
 from ....config import config
-from ....backend_interface import Task, TaskStatusEnum
+from ....backend_api.services import tasks
 
 
 class TaskStopReason(object):
@@ -13,14 +13,16 @@ class TaskStopSignal(object):
 
     _number_of_consecutive_reset_tests = 4
 
-    _unexpected_statuses = (
+    # _unexpected_statuses = (
-        TaskStatusEnum.closed,
+    #     tasks.TaskStatusEnum.closed,
-        TaskStatusEnum.stopped,
+    #     tasks.TaskStatusEnum.stopped,
-        TaskStatusEnum.failed,
+    #     tasks.TaskStatusEnum.failed,
-        TaskStatusEnum.published,
+    #     tasks.TaskStatusEnum.published,
-    )
+    #     tasks.TaskStatusEnum.completed,
+    # )
 
     def __init__(self, task):
+        from ....backend_interface import Task
         assert isinstance(task, Task)
         self.task = task
         self._task_reset_state_counter = 0
@@ -29,13 +31,19 @@ class TaskStopSignal(object):
         status = self.task.status
         message = self.task.data.status_message
 
-        if status == TaskStatusEnum.in_progress and "stopping" in message:
+        if status == tasks.TaskStatusEnum.in_progress and "stopping" in message:
             return TaskStopReason.stopped
 
-        if status in self._unexpected_statuses and "worker" not in message:
+        _expected_statuses = (
+            tasks.TaskStatusEnum.created,
+            tasks.TaskStatusEnum.queued,
+            tasks.TaskStatusEnum.in_progress,
+        )
+
+        if status not in _expected_statuses and "worker" not in message:
             return TaskStopReason.status_changed
 
-        if status == TaskStatusEnum.created:
+        if status == tasks.TaskStatusEnum.created:
             self._task_reset_state_counter += 1
 
             if self._task_reset_state_counter >= self._number_of_consecutive_reset_tests:

trains/backend_interface/task/development/worker.py

@@ -1,26 +1,70 @@
 from socket import gethostname
 
 import attr
+from threading import Thread, Event
 
-from ....config import config, running_remotely, dev_worker_name
+from time import time
+
+from ....config import config
+from ....backend_interface.task.development.stop_signal import TaskStopSignal
+from ....backend_api.services import tasks
 
 
-@attr.s
 class DevWorker(object):
     prefix = attr.ib(type=str, default="MANUAL:")
 
     report_period = float(config.get('development.worker.report_period_sec', 30.))
     report_stdout = bool(config.get('development.worker.log_stdout', True))
+    ping_period = 30.
 
-    @classmethod
+    def __init__(self):
-    def is_enabled(cls, model_updated=False):
+        self._dev_stop_signal = None
-        return False
+        self._thread = None
+        self._exit_event = Event()
+        self._task = None
+        self._support_ping = False
 
-    def status_report(self, timestamp=None):
+    def ping(self, timestamp=None):
+        try:
+            if self._task:
+                self._task.send(tasks.PingRequest(self._task.id))
+        except Exception:
+            return False
         return True
 
-    def register(self):
+    def register(self, task):
+        if self._thread:
+            return True
+        if TaskStopSignal.enabled:
+            self._dev_stop_signal = TaskStopSignal(task=task)
+        self._support_ping = hasattr(tasks, 'PingRequest')
+        # if there is nothing to monitor, leave
+        if not self._support_ping and not self._dev_stop_signal:
+            return
+        self._task = task
+        self._exit_event.clear()
+        self._thread = Thread(target=self._daemon)
+        self._thread.daemon = True
+        self._thread.start()
         return True
 
+    def _daemon(self):
+        last_ping = time()
+        while self._task is not None:
+            if self._exit_event.wait(min(self.ping_period, self.report_period)):
+                return
+            # send ping request
+            if self._support_ping and (time() - last_ping) >= self.ping_period:
+                self.ping()
+                last_ping = time()
+            if self._dev_stop_signal:
+                stop_reason = self._dev_stop_signal.test()
+                if stop_reason and self._task:
+                    self._task._dev_mode_stop_task(stop_reason)
+
     def unregister(self):
+        self._exit_event.set()
+        self._dev_stop_signal = None
+        self._thread = None
+        self._task = None
         return True