pycompat: export queue module instead of symbols in module (API) Previously, pycompat and util re-exported individual symbols from the queue module. This had the side-effect of forcing the loading of the queue module whenever pycompat/util was imported. These symbols aren't used very often. So importing the module to get a handle on the symbols is wasteful. This commit changes pycompat so it no longer exports the individual symbols in the queue module. Instead, we make the imported module a "public" symbol. We drop the individual symbol aliases from the util module. All consumers are updated to use pycompat.queue.* instead. This change makes 300 invocations of `hg log -r. -T '{rev}\n'` a little faster: before: 18.44s after: 17.87s Differential Revision: https://phab.mercurial-scm.org/D3441

--- a/mercurial/vfs.py	Sat May 05 18:41:51 2018 -0700
+++ b/mercurial/vfs.py	Sat May 05 18:35:16 2018 -0700
@@ -568,7 +568,7 @@
         ui.debug('starting %d threads for background file closing\n' %
                  threadcount)
 
-        self._queue = util.queue(maxsize=maxqueue)
+        self._queue = pycompat.queue.Queue(maxsize=maxqueue)
         self._running = True
 
         for i in range(threadcount):
@@ -600,7 +600,7 @@
                 except Exception as e:
                     # Stash so can re-raise from main thread later.
                     self._threadexception = e
-            except util.empty:
+            except pycompat.queue.Empty:
                 if not self._running:
                     break