Issue #12040: Expose a new attribute `sentinel` on instances of

:class:`multiprocessing.Process`.  Also, fix Process.join() to not use
polling anymore, when given a timeout.

1 files changed, 12 insertions, 0 deletions

diff --git a/Lib/multiprocessing/process.py b/Lib/multiprocessing/process.py
index 3fb9ff6..99ee532 100644
--- a/Lib/multiprocessing/process.py
+++ b/Lib/multiprocessing/process.py
@@ -132,6 +132,7 @@ class Process(object):
         else:
             from .forking import Popen
         self._popen = Popen(self)
+        self._sentinel = self._popen.sentinel
         _current_process._children.add(self)
 
     def terminate(self):
@@ -218,6 +219,17 @@ class Process(object):
 
     pid = ident
 
+    @property
+    def sentinel(self):
+        '''
+        Return a file descriptor (Unix) or handle (Windows) suitable for
+        waiting for process termination.
+        '''
+        try:
+            return self._sentinel
+        except AttributeError:
+            raise ValueError("process not started")
+
     def __repr__(self):
         if self is _current_process:
             status = 'started'