libuv sets ref status on start; timer watchers special case start references....

libuv sets ref status on start; timer watchers special case start references. fixes test__queue and test__order.

src/gevent/_ffi/watcher.py

@@ -147,6 +147,7 @@ class watcher(object):
             self._watcher_ffi_set_priority(priority)
 
         self._watcher_ffi_init(args)
+        self._watcher_ffi_set_init_ref(ref)
 
     def _watcher_create(self, ref): # pylint:disable=unused-argument
         self._handle = type(self).new_handle(self)
@@ -157,6 +158,9 @@ class watcher(object):
     def _watcher_new(self):
         return type(self).new(self._watcher_struct_pointer_type)
 
+    def _watcher_ffi_set_init_ref(self, ref):
+        pass
+
     def _watcher_ffi_set_priority(self, priority):
         pass
 
@@ -268,9 +272,9 @@ class watcher(object):
             raise TypeError('callback must be callable, not None')
         self.callback = callback
         self.args = args or _NOARGS
-        self._watcher_ffi_start_unref()
         self.loop._keepaliveset.add(self)
         self._watcher_ffi_start()
+        self._watcher_ffi_start_unref()
 
     def stop(self):
         self._watcher_ffi_stop_ref()

src/gevent/libev/watcher.py

@@ -68,6 +68,12 @@ class watcher(_base.watcher):
     _LIB = libev
     _watcher_prefix = 'ev'
 
+    # Flags is a bitfield with the following meaning:
+    # 0000 -> default, referenced (when active)
+    # 0010 -> ev_unref has been called
+    # 0100 -> not referenced; independent of 0010
+    _flags = 0
+
     def __init__(self, _loop, ref=True, priority=None, args=_base._NOARGS):
         if ref:
             self._flags = 0
@@ -88,14 +94,15 @@ class watcher(_base.watcher):
         self._watcher_start(self.loop._ptr, self._watcher)
 
     def _watcher_ffi_ref(self):
-        if self._flags & 2:
+        if self._flags & 2: # we've told libev we're not referenced
             self.loop.ref()
             self._flags &= ~2
 
     def _watcher_ffi_unref(self):
         if self._flags & 6 == 4:
+            # We're not referenced, but we haven't told libev that
             self.loop.unref()
-            self._flags |= 2
+            self._flags |= 2 # now we've told libev
 
     def _get_ref(self):
         return False if self._flags & 4 else True
@@ -110,10 +117,12 @@ class watcher(_base.watcher):
         else:
             if self._flags & 4:
                 return  # ref is already False
-            self._flags |= 4
+            self._flags |= 4 # we're not referenced
             if not self._flags & 2 and libev.ev_is_active(self._watcher):
+                # we haven't told libev we're not referenced, but it thinks we're
+                # active so we need to undo that
                 self.loop.unref()
-                self._flags |= 2
+                self._flags |= 2 # libev knows we're not referenced
 
     ref = property(_get_ref, _set_ref)
 

src/gevent/libuv/watcher.py

@@ -60,6 +60,9 @@ class watcher(_base.watcher):
         del self._watcher
 
 
+    def _watcher_ffi_set_init_ref(self, ref):
+        self.ref = ref
+
     def _watcher_ffi_set_priority(self, priority):
         # libuv has no concept of priority
         pass
@@ -302,6 +305,16 @@ class timer(_base.TimerMixin, watcher):
 
     _again = False
 
+    def _watcher_ffi_start_unref(self):
+        # Don't manipulate the ref status different from
+        # how we were created. Doing so causes test__queue
+        # to have lots of LoopExit exceptions.
+        # XXX It's not totally clear why.
+        pass
+
+    def _watcher_ffi_stop_ref(self):
+        pass
+
     def _watcher_ffi_init(self, args):
         self._watcher_init(self.loop._ptr, self._watcher)
         self._after, self._repeat = args