Issue #28600: Optimize loop.call_soon().

Run expensive type checks only in debug mode.  In addition, stop
supporting passing handles to loop.run_in_executor.

2 files changed, 19 insertions, 22 deletions

diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py
index b3e318e..ddf041d 100644
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
@@ -528,12 +528,10 @@ class BaseEventLoop(events.AbstractEventLoop):
 
         Absolute time corresponds to the event loop's time() method.
         """
-        if (coroutines.iscoroutine(callback)
-        or coroutines.iscoroutinefunction(callback)):
-            raise TypeError("coroutines cannot be used with call_at()")
         self._check_closed()
         if self._debug:
             self._check_thread()
+            self._check_callback(callback, 'call_at')
         timer = events.TimerHandle(when, callback, args, self)
         if timer._source_traceback:
             del timer._source_traceback[-1]
@@ -551,18 +549,27 @@ class BaseEventLoop(events.AbstractEventLoop):
         Any positional arguments after the callback will be passed to
         the callback when it is called.
         """
+        self._check_closed()
         if self._debug:
             self._check_thread()
+            self._check_callback(callback, 'call_soon')
         handle = self._call_soon(callback, args)
         if handle._source_traceback:
             del handle._source_traceback[-1]
         return handle
 
+    def _check_callback(self, callback, method):
+        if (coroutines.iscoroutine(callback) or
+                coroutines.iscoroutinefunction(callback)):
+            raise TypeError(
+                "coroutines cannot be used with {}()".format(method))
+        if not callable(callback):
+            raise TypeError(
+                'a callable object was expected by {}(), got {!r}'.format(
+                    method, callback))
+
+
     def _call_soon(self, callback, args):
-        if (coroutines.iscoroutine(callback)
-        or coroutines.iscoroutinefunction(callback)):
-            raise TypeError("coroutines cannot be used with call_soon()")
-        self._check_closed()
         handle = events.Handle(callback, args, self)
         if handle._source_traceback:
             del handle._source_traceback[-1]
@@ -588,6 +595,9 @@ class BaseEventLoop(events.AbstractEventLoop):
 
     def call_soon_threadsafe(self, callback, *args):
         """Like call_soon(), but thread-safe."""
+        self._check_closed()
+        if self._debug:
+            self._check_callback(callback, 'call_soon_threadsafe')
         handle = self._call_soon(callback, args)
         if handle._source_traceback:
             del handle._source_traceback[-1]
@@ -595,21 +605,9 @@ class BaseEventLoop(events.AbstractEventLoop):
         return handle
 
     def run_in_executor(self, executor, func, *args):
-        if (coroutines.iscoroutine(func)
-        or coroutines.iscoroutinefunction(func)):
-            raise TypeError("coroutines cannot be used with run_in_executor()")
         self._check_closed()
-        if isinstance(func, events.Handle):
-            assert not args
-            assert not isinstance(func, events.TimerHandle)
-            warnings.warn(
-                "Passing Handle to loop.run_in_executor() is deprecated",
-                DeprecationWarning)
-            if func._cancelled:
-                f = self.create_future()
-                f.set_result(None)
-                return f
-            func, args = func._callback, func._args
+        if self._debug:
+            self._check_callback(func, 'run_in_executor')
         if executor is None:
             executor = self._default_executor
             if executor is None:
diff --git a/Lib/asyncio/events.py b/Lib/asyncio/events.py
index 3a33646..b89b4b2 100644
--- a/Lib/asyncio/events.py
+++ b/Lib/asyncio/events.py
@@ -82,7 +82,6 @@ class Handle:
                  '_source_traceback', '_repr', '__weakref__')
 
     def __init__(self, callback, args, loop):
-        assert not isinstance(callback, Handle), 'A Handle is not a callback'
         self._loop = loop
         self._callback = callback
         self._args = args