Create runtime variables

tractor/_state.py

@@ -3,10 +3,15 @@ Per process state
 """
 from typing import Optional
 from collections import Mapping
+import multiprocessing as mp
 
 import trio
 
 _current_actor: Optional['Actor'] = None  # type: ignore
+_runtime_vars = {
+    '_debug_mode': False,
+    '_is_root': False,
+}
 
 
 def current_actor() -> 'Actor':  # type: ignore
@@ -36,3 +41,20 @@ class ActorContextInfo(Mapping):
         except RuntimeError:
             # no local actor/task context initialized yet
             return f'no {key} context'
+
+
+def is_main_process() -> bool:
+    """Bool determining if this actor is running in the top-most process.
+    """
+    return mp.current_process().name == 'MainProcess'
+
+
+def debug_mode() -> bool:
+    """Bool determining if "debug mode" is on which enables
+    remote subactor pdb entry on crashes.
+    """
+    return _runtime_vars['_debug_mode']
+
+
+def is_root_process() -> bool:
+    return _runtime_vars['_is_root']