- Make processes non-daemonic

- Deprecate terminator argument

parfor/__init__.py

@@ -2,7 +2,6 @@ import multiprocessing
 from os import getpid
 from tqdm.auto import tqdm
 from traceback import format_exc
-from psutil import Process
 from collections import OrderedDict
 from warnings import warn
 from functools import wraps
@@ -35,12 +34,15 @@ class Chunks:
         # s, r and n are deprecated
         if s is not None:
             warn('parfor: use of \'s\' is deprecated, use \'size\' instead', DeprecationWarning, stacklevel=2)
+            warn('parfor: use of \'s\' is deprecated, use \'size\' instead', DeprecationWarning, stacklevel=3)
             size = s
         if n is not None:
             warn('parfor: use of \'n\' is deprecated, use \'number\' instead', DeprecationWarning, stacklevel=2)
+            warn('parfor: use of \'n\' is deprecated, use \'number\' instead', DeprecationWarning, stacklevel=3)
             number = n
         if r is not None:
             warn('parfor: use of \'r\' is deprecated, use \'ratio\' instead', DeprecationWarning, stacklevel=2)
+            warn('parfor: use of \'r\' is deprecated, use \'ratio\' instead', DeprecationWarning, stacklevel=3)
             ratio = r
         if length is None:
             try:
@@ -241,12 +243,23 @@ class Task:
             return 'Task {}'.format(self.handle)
 
 
+class Context(multiprocessing.context.SpawnContext):
+    """ Provide a context where child processes never are daemonic. """
+    class Process(multiprocessing.context.SpawnProcess):
+        @property
+        def daemon(self):
+            return False
+
+        @daemon.setter
+        def daemon(self, value):
+            pass
+
+
 class Parpool:
     """ Parallel processing with addition of iterations at any time and request of that result any time after that.
         The target function and its argument can be changed at any time.
     """
-    def __init__(self, fun=None, args=None, kwargs=None, rP=None, nP=None, bar=None, qbar=None, terminator=None,
-                 qsize=None):
+    def __init__(self, fun=None, args=None, kwargs=None, rP=None, nP=None, bar=None, qbar=None, qsize=None):
         """ fun, args, kwargs: target function and its arguments and keyword arguments
             rP: ratio workers to cpu cores, default: 1
             nP: number of workers, default, None, overrides rP if not None
@@ -259,16 +272,13 @@ class Parpool:
             self.nP = int(nP)
         self.nP = max(self.nP, 2)
         self.task = Task(fun, args, kwargs)
-        if hasattr(multiprocessing, 'get_context'):
-            ctx = multiprocessing.get_context('spawn')
-        else:
-            ctx = multiprocessing
         self.is_started = False
+        ctx = Context()
         self.n_tasks = ctx.Value('i', self.nP)
         self.event = ctx.Event()
         self.queue_in = ctx.Queue(qsize or 3 * self.nP)
         self.queue_out = ctx.Queue(qsize or 12 * self.nP)
-        self.pool = ctx.Pool(self.nP, self._Worker(self.queue_in, self.queue_out, self.n_tasks, self.event, terminator))
+        self.pool = ctx.Pool(self.nP, self._Worker(self.queue_in, self.queue_out, self.n_tasks, self.event))
         self.is_alive = True
         self.handle = 0
         self.tasks = {}
@@ -292,7 +302,7 @@ class Parpool:
             return True
         except multiprocessing.queues.Empty:
             for handle, task in self.tasks.items():  # retry a task if the process doing it was killed
-                if task.pid is not None and task.pid not in [child.pid for child in Process().children()]:
+                if task.pid is not None and task.pid not in [child.pid for child in multiprocessing.active_children()]:
                     self.queue_in.put(task)
                     warn('Task {} was restarted because process {} was probably killed.'.format(task.handle, task.pid))
             return False
@@ -435,13 +445,12 @@ class Parpool:
 
     class _Worker(object):
         """ Manages executing the target function which will be executed in different processes. """
-        def __init__(self, queue_in, queue_out, n_tasks, event, terminator, cachesize=48):
+        def __init__(self, queue_in, queue_out, n_tasks, event, cachesize=48):
             self.cache = DequeDict(cachesize)
             self.queue_in = queue_in
             self.queue_out = queue_out
             self.n_tasks = n_tasks
             self.event = event
-            self.terminator = dumps(terminator, recurse=True)
 
         def add_to_queue(self, *args):
             while not self.event.is_set():
@@ -468,10 +477,8 @@ class Parpool:
                 except Exception:
                     self.add_to_queue('error', format_exc())
                     self.event.set()
-            terminator = loads(self.terminator)
-            kill_vm()
-            if terminator is not None:
-                terminator()
+            for child in multiprocessing.active_children():
+                child.kill()
             with self.n_tasks.get_lock():
                 self.n_tasks.value -= 1
 
@@ -494,7 +501,6 @@ def pmap(fun, iterable=None, args=None, kwargs=None, total=None, desc=None, bar=
             bar:    bool enable progress bar,
                         or a callback function taking the number of passed iterations as an argument
             pbar:   bool enable buffer indicator bar, or a callback function taking the queue size as an argument
-            terminator: function which is executed in each worker after all the work is done
             rP:     ratio workers to cpu cores, default: 1
             nP:     number of workers, default, None, overrides rP if not None
             serial: execute in series instead of parallel if True, None (default): let pmap decide
@@ -551,6 +557,12 @@ def pmap(fun, iterable=None, args=None, kwargs=None, total=None, desc=None, bar=
     if total is None and length is not None:
         total = length
         warn('parfor: use of \'length\' is deprecated, use \'total\' instead', DeprecationWarning, stacklevel=2)
+        warn('parfor: use of \'length\' is deprecated, use \'total\' instead', DeprecationWarning, stacklevel=3)
+    if terminator is not None:
+        warn('parfor: use of \'terminator\' is deprecated, workers are terminated automatically',
+             DeprecationWarning, stacklevel=2)
+        warn('parfor: use of \'terminator\' is deprecated, workers are terminated automatically',
+             DeprecationWarning, stacklevel=3)
     is_chunked = isinstance(iterable, Chunks)
     if is_chunked:
         chunk_fun = fun
@@ -578,7 +590,7 @@ def pmap(fun, iterable=None, args=None, kwargs=None, total=None, desc=None, bar=
         with ExternalBar(callback=qbar) if callable(qbar) \
                 else TqdmMeter(total=0, desc='Task buffer', disable=not qbar, leave=False) as qbar, \
              ExternalBar(callback=bar) if callable(bar) else tqdm(**bar_kwargs) as bar:
-            with Parpool(chunk_fun, args, kwargs, rP, nP, bar, qbar, terminator, qsize) as p:
+            with Parpool(chunk_fun, args, kwargs, rP, nP, bar, qbar, qsize) as p:
                 for i, (j, l) in enumerate(zip(iterable, iterable.lengths)):  # add work to the queue
                     p(j, handle=i, barlength=iterable.lengths[i])
                     if bar.total is None or bar.total < i+1:
@@ -603,6 +615,8 @@ def deprecated(cls, name):
     def wrapper(*args, **kwargs):
         warn(f'parfor: use of \'{name}\' is deprecated, use \'{cls.__name__}\' instead',
              category=DeprecationWarning, stacklevel=2)
+        warn(f'parfor: use of \'{name}\' is deprecated, use \'{cls.__name__}\' instead',
+             category=DeprecationWarning, stacklevel=3)
         return cls(*args, **kwargs)
     return wrapper