fix: restructure depends_on flag. No using dicts to store dependent processes and only start process if all dependent processes are in RUNNING state

Author: Michael Hammann

supervisor/process.py

@@ -195,12 +195,6 @@ def spawn(self):
 
         Return the process id.  If the fork() call fails, return None.
         """
-        # check if the process is dependent upon any other process and if so make sure that one is in the RUNNING state
-        if self.config.depends_on is not None:
-            for process in enumerate(self.config.depends_on):
-                if self.config.depends_on[process[0]].state not in RUNNING_STATES:
-                    self.config.depends_on[process[0]].spawn()
-
         options = self.config.options
         processname = as_string(self.config.name)
 

supervisor/rpcinterface.py

@@ -281,6 +281,31 @@ def startProcess(self, name, wait=True):
         @return boolean result     Always true unless error
 
         """
+        # check if the process is dependent upon any other process and if so make sure that one is in the RUNNING state
+        group, process = self._getGroupAndProcess(name)
+        if process.config.depends_on is not None:
+            # keep track of RUNNING childs
+            running_childs = set()
+            # wait/loop until all childs are running
+            while set(process.config.depends_on.keys()) != running_childs:
+                for child in process.config.depends_on.values():
+                    if child.get_state() != ProcessStates.RUNNING:
+                        # potentially remove child, if it is in running list
+                        if child.config.name in running_childs:
+                            running_childs.remove(child.config.name)
+                        # check if it needs to be started
+                        if child.state is not (ProcessStates.STARTING or ProcessStates.RUNNING):
+                            self.startProcess(child.config.name)
+                        else:
+                            child.transition()
+                            msg = ("waiting on dependee process {} to reach running state - currently in {}"
+                            .format(child.config.name, getProcessStateDescription(child.state)))
+                            self.supervisord.options.logger.warn(msg)
+                    else:
+                        # child is running - add to set
+                        running_childs.add(child.config.name)
+                time.sleep(0.5)
+
         self._update('startProcess')
         group, process = self._getGroupAndProcess(name)
         if process is None:

supervisor/supervisord.py

@@ -92,7 +92,7 @@ def run(self):
                 # check dependencies for all programs in group:
                 for conf in enumerate(config.process_configs):
                     if config.process_configs[conf[0]].depends_on is not None:
-                        processes=[]
+                        process_dict=dict({})
                         # split to get all processes in case there are multiple dependencies
                         dependent_processes = (config.process_configs[conf[0]].depends_on).split()
                         for process in dependent_processes:
@@ -102,8 +102,8 @@ def run(self):
                             except:
                                 dependent_group=dependent_process=process
                             g.addEdge(config.process_configs[conf[0]].name, dependent_process)
-                            processes.append(self.process_groups[dependent_group].processes[dependent_process])
-                        config.process_configs[conf[0]].depends_on = processes
+                            process_dict[dependent_process] = self.process_groups[dependent_group].processes[dependent_process]
+                        config.process_configs[conf[0]].depends_on = process_dict
             # check for cyclical process dependencies
             if g.cyclic() == 1:
                 raise AttributeError('Process config contains dependeny cycle(s)! Check config files again!')