Expose a Process.sentinel property (and fix polling loop in Process.join())

Lib/multiprocessing/util.py

 #
 # Module providing various facilities to other parts of the package
 #
 # multiprocessing/util.py
 #
 # Copyright (c) 2006-2008, R Oudkerk
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ skipping 14 matching lines @@
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
+import functools
 import itertools
 import weakref
 import atexit
+import select
 import threading        # we want threading to install it's
                         # cleanup function before multiprocessing does
 
 from multiprocessing.process import current_process, active_children
 
 __all__ = [
     'sub_debug', 'debug', 'info', 'sub_warning', 'get_logger',
     'log_to_stderr', 'get_temp_dir', 'register_after_fork',
     'is_exiting', 'Finalize', 'ForkAwareThreadLock', 'ForkAwareLocal',
     'SUBDEBUG', 'SUBWARNING',
@@ skipping 260 matching lines @@
         self._lock = threading.Lock()
         self.acquire = self._lock.acquire
         self.release = self._lock.release
         register_after_fork(self, ForkAwareThreadLock.__init__)
 
 class ForkAwareLocal(threading.local):
     def __init__(self):
         register_after_fork(self, lambda obj : obj.__dict__.clear())
     def __reduce__(self):
         return type(self), ()
+
+
+#
+# Automatic retry after EINTR
+#
+
+def eintr_retry(func, _errors=(EnvironmentError, select.error)):
+    @functools.wraps(func)
+    def wrapped(*args, **kwargs):
+        while True:
+            try:
+                return func(*args, **kwargs)
+            except _errors as e:
+                # select.error has no `errno` attribute
+                if e.args[0] == errno.EINTR:
+                    continue
+                raise
+    return wrapped
+