1 files changed, 38 insertions, 15 deletions
diff --git a/Lib/multiprocessing/pool.py b/Lib/multiprocessing/pool.py
index fc9d904..8082ad6 100644
--- a/Lib/multiprocessing/pool.py
+++ b/Lib/multiprocessing/pool.py
@@ -17,9 +17,11 @@ import threading
 import queue
 import itertools
 import collections
+import os
 import time
+import traceback
 
-from multiprocessing import Process, cpu_count, TimeoutError
+from multiprocessing import Process, TimeoutError
 from multiprocessing.util import Finalize, debug
 
 #
@@ -43,6 +45,29 @@ def starmapstar(args):
     return list(itertools.starmap(args[0], args[1]))
 
 #
+# Hack to embed stringification of remote traceback in local traceback
+#
+
+class RemoteTraceback(Exception):
+    def __init__(self, tb):
+        self.tb = tb
+    def __str__(self):
+        return self.tb
+
+class ExceptionWithTraceback:
+    def __init__(self, exc, tb):
+        tb = traceback.format_exception(type(exc), exc, tb)
+        tb = ''.join(tb)
+        self.exc = exc
+        self.tb = '\n"""\n%s"""' % tb
+    def __reduce__(self):
+        return rebuild_exc, (self.exc, self.tb)
+
+def rebuild_exc(exc, tb):
+    exc.__cause__ = RemoteTraceback(tb)
+    return exc
+
+#
 # Code run by worker processes
 #
 
@@ -78,8 +103,8 @@ def worker(inqueue, outqueue, initializer=None, initargs=(), maxtasks=None):
     while maxtasks is None or (maxtasks and completed < maxtasks):
         try:
             task = get()
-        except (EOFError, IOError):
-            debug('worker got EOFError or IOError -- exiting')
+        except (EOFError, OSError):
+            debug('worker got EOFError or OSError -- exiting')
             break
 
         if task is None:
@@ -90,6 +115,7 @@ def worker(inqueue, outqueue, initializer=None, initargs=(), maxtasks=None):
         try:
             result = (True, func(*args, **kwds))
         except Exception as e:
+            e = ExceptionWithTraceback(e, e.__traceback__)
             result = (False, e)
         try:
             put((job, i, result))
@@ -122,10 +148,7 @@ class Pool(object):
         self._initargs = initargs
 
         if processes is None:
-            try:
-                processes = cpu_count()
-            except NotImplementedError:
-                processes = 1
+            processes = os.cpu_count() or 1
         if processes < 1:
             raise ValueError("Number of processes must be at least 1")
 
@@ -349,7 +372,7 @@ class Pool(object):
                     break
                 try:
                     put(task)
-                except IOError:
+                except OSError:
                     debug('could not put task on queue')
                     break
             else:
@@ -371,8 +394,8 @@ class Pool(object):
             debug('task handler sending sentinel to workers')
             for p in pool:
                 put(None)
-        except IOError:
-            debug('task handler got IOError when sending sentinels')
+        except OSError:
+            debug('task handler got OSError when sending sentinels')
 
         debug('task handler exiting')
 
@@ -383,8 +406,8 @@ class Pool(object):
         while 1:
             try:
                 task = get()
-            except (IOError, EOFError):
-                debug('result handler got EOFError/IOError -- exiting')
+            except (OSError, EOFError):
+                debug('result handler got EOFError/OSError -- exiting')
                 return
 
             if thread._state:
@@ -405,8 +428,8 @@ class Pool(object):
         while cache and thread._state != TERMINATE:
             try:
                 task = get()
-            except (IOError, EOFError):
-                debug('result handler got EOFError/IOError -- exiting')
+            except (OSError, EOFError):
+                debug('result handler got EOFError/OSError -- exiting')
                 return
 
             if task is None:
@@ -428,7 +451,7 @@ class Pool(object):
                     if not outqueue._reader.poll():
                         break
                     get()
-            except (IOError, EOFError):
+            except (OSError, EOFError):
                 pass
 
         debug('result handler exiting: len(cache)=%s, thread._state=%s',