Simplify getting the repr for greenlet functions and return the args/kwargs in more circumstances.

CHANGES.rst

@@ -88,10 +88,12 @@
 - Greenlet objects now keep track of their spawning parent greenlet
   and the code location that spawned them, in addition to maintaining
   a "spawn tree local" mapping. Based on a proposal from PayPal and
-  comments by Mahmoud Hashemi and Kurt Rose. See :issue:`755`.
+  comments by Mahmoud Hashemi and Kurt Rose. See :issue:`755` and
+  :pr:`1115`.
 
 - The :mod:`gevent.greenlet` module is now compiled with Cython to
-  offset any performance loss due to :issue:`755`.
+  offset any performance decrease due to :issue:`755`. Please open
+  issues for any compatibility concerns. See :pr:`1115`.
 
 1.3a1 (2018-01-27)
 ==================

src/gevent/greenlet.pxd

@@ -49,12 +49,14 @@ cdef class Greenlet(greenlet):
     cdef object _notifier
     cdef object _start_event
     cdef dict _kwargs
+    cdef str _formatted_info
 
     cpdef bint has_links(self)
     cpdef join(self, timeout=*)
     cpdef bint ready(self)
     cpdef bint successful(self)
     cpdef rawlink(self, object callback)
+    cpdef str _formatinfo(self)
 
     cdef bint __started_but_aborted(self)
     cdef bint __start_cancelled_by_kill(self)

src/gevent/greenlet.py

@@ -9,7 +9,6 @@ from weakref import ref as wref
 from greenlet import greenlet
 from greenlet import getcurrent
 
-from gevent._compat import PY3
 from gevent._compat import PYPY
 from gevent._compat import reraise
 from gevent._tblib import dump_traceback
@@ -244,6 +243,7 @@ class Greenlet(greenlet):
         self._kwargs = kwargs
         self.value = None
         self._notifier = None
+        self._formatted_info = None
         self._links = []
 
         # Initial state: None.
@@ -393,19 +393,24 @@ class Greenlet(greenlet):
             result += ': ' + formatted
         return result + '>'
 
-    _formatted_info = None
 
     def _formatinfo(self):
         info = self._formatted_info
         if info is not None:
             return info
 
-        try:
-            result = getfuncname(self.__dict__['_run'])
-        except Exception: # pylint:disable=broad-except
-            # Don't cache
-            return ''
+        # Are we running an arbitrary function provided to the constructor,
+        # or did a subclass override _run?
+        func = self._run
+        im_self = getattr(func, '__self__', None)
+        if im_self is self:
+            funcname = '_run'
+        elif im_self is not None:
+            funcname = repr(func)
+        else:
+            funcname = getattr(func, '__name__', '') or repr(func)
 
+        result = funcname
         args = []
         if self.args:
             args = [repr(x)[:50] for x in self.args]
@@ -672,7 +677,7 @@ class Greenlet(greenlet):
             self._report_result(result)
         finally:
             self.__dict__.pop('_run', None)
-            self.args = None
+            self.args = ()
             self._kwargs = None
 
     def _run(self):
@@ -880,21 +885,3 @@ def killall(greenlets, exception=GreenletExit, block=True, timeout=None):
             t.cancel()
     else:
         loop.run_callback(_killall, greenlets, exception)
-
-
-if PY3:
-    _meth_self = "__self__"
-else:
-    _meth_self = "im_self"
-
-
-def getfuncname(func):
-    if not hasattr(func, _meth_self):
-        try:
-            funcname = func.__name__
-        except AttributeError:
-            pass
-        else:
-            if funcname != '<lambda>':
-                return funcname
-    return repr(func)

src/greentest/test__greenlet.py

@@ -405,6 +405,8 @@ class A(object):
 
 hexobj = re.compile('-?0x[0123456789abcdef]+L?', re.I)
 
+class Subclass(gevent.Greenlet):
+    pass
 
 class TestStr(greentest.TestCase):
 
@@ -428,6 +430,17 @@ class TestStr(greentest.TestCase):
         str_g = str_g.replace(__name__, 'module')
         self.assertEqual(str_g, '<Greenlet at X: <bound method A.method of <module.A object at X>>>')
 
+    def test_subclass(self):
+        g = Subclass()
+        str_g = hexobj.sub('X', str(g))
+        str_g = str_g.replace(__name__, 'module')
+        self.assertEqual(str_g, '<Subclass at X: _run>')
+
+        g = Subclass(None, 'question', answer=42)
+        str_g = hexobj.sub('X', str(g))
+        str_g = str_g.replace(__name__, 'module')
+        self.assertEqual(str_g, "<Subclass at X: _run('question', answer=42)>")
+
 
 class TestJoin(AbstractGenericWaitTestCase):