Disable multiprocessing to avoid unresolved deadlocks

Remove the use of multiprocessing in order to avoid unresolved deadlocks
some of our users are hitting. The wrapper class is preserved, so that
multiprocessing can be reintroduced when the issue is resolved.

1 files changed, 10 insertions, 17 deletions

diff --git a/gemato/util.py b/gemato/util.py
index eb052b6..94006a6 100644
--- a/gemato/util.py
+++ b/gemato/util.py
@@ -3,44 +3,37 @@
 # (c) 2017-2018 Michał Górny
 # Licensed under the terms of 2-clause BSD license
 
-import multiprocessing
-import sys
-
 
 class MultiprocessingPoolWrapper(object):
     """
     A portability wrapper for multiprocessing.Pool that supports
     context manager API (and any future hacks we might need).
+
+    Note: the multiprocessing behavior has been temporarily removed
+    due to unresolved deadlocks. It will be restored once the cause
+    of the issues is found and fixed or worked around.
     """
 
-    __slots__ = ['pool']
+    __slots__ = []
 
     def __init__(self, processes):
-        self.pool = multiprocessing.Pool(processes=processes)
+        pass
 
     def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_value, exc_cb):
-        if exc_type is None:
-            self.pool.close()
-            self.pool.join()
-        self.pool.terminate()
+        pass
 
-    def map(self, *args, **kwargs):
-        return self.pool.map(*args, **kwargs)
+    def map(self, func, it, chunksize=None):
+        return map(func, it)
 
     def imap_unordered(self, *args, **kwargs):
         """
         Use imap_unordered() if available and safe to use. Fall back
         to regular map() otherwise.
         """
-        if sys.hexversion >= 0x03050400:
-            return self.pool.imap_unordered(*args, **kwargs)
-        else:
-            # in py<3.5.4 imap() swallows exceptions, so fall back
-            # to regular map()
-            return self.pool.map(*args, **kwargs)
+        return self.map(*args, **kwargs)
 
 
 def path_starts_with(path, prefix):