[pypy-commit] pypy default: Merge refactor-wrapped-del: clean up and generalize the

arigo noreply at buildbot.pypy.org
Wed Jul 13 14:16:57 CEST 2011


Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r45543:f9a24c80bd03
Date: 2011-07-13 14:16 +0200
http://bitbucket.org/pypy/pypy/changeset/f9a24c80bd03/

Log:	Merge refactor-wrapped-del: clean up and generalize the way our
	W_Root's __del__ works. They should not do too much, which is now
	checked during translation, but they can call
	self.enqueue_for_destruction() by passing them a callback, possibly
	several times. The callbacks are invoked at a later safe point.

diff --git a/pypy/interpreter/baseobjspace.py b/pypy/interpreter/baseobjspace.py
--- a/pypy/interpreter/baseobjspace.py
+++ b/pypy/interpreter/baseobjspace.py
@@ -130,6 +130,9 @@
         raise operationerrfmt(space.w_TypeError,
             "cannot create weak reference to '%s' object", typename)
 
+    def delweakref(self):
+        pass
+
     def clear_all_weakrefs(self):
         """Call this at the beginning of interp-level __del__() methods
         in subclasses.  It ensures that weakrefs (if any) are cleared
@@ -143,29 +146,28 @@
             # app-level, e.g. a user-defined __del__(), and this code
             # tries to use weakrefs again, it won't reuse the broken
             # (already-cleared) weakrefs from this lifeline.
-            self.setweakref(lifeline.space, None)
+            self.delweakref()
             lifeline.clear_all_weakrefs()
 
-    __already_enqueued_for_destruction = False
+    __already_enqueued_for_destruction = ()
 
-    def _enqueue_for_destruction(self, space, call_user_del=True):
+    def enqueue_for_destruction(self, space, callback, descrname):
         """Put the object in the destructor queue of the space.
-        At a later, safe point in time, UserDelAction will use
-        space.userdel() to call the object's app-level __del__ method.
+        At a later, safe point in time, UserDelAction will call
+        callback(self).  If that raises OperationError, prints it
+        to stderr with the descrname string.
+
+        Note that 'callback' will usually need to start with:
+            assert isinstance(self, W_SpecificClass)
         """
         # this function always resurect the object, so when
         # running on top of CPython we must manually ensure that
         # we enqueue it only once
         if not we_are_translated():
-            if self.__already_enqueued_for_destruction:
+            if callback in self.__already_enqueued_for_destruction:
                 return
-            self.__already_enqueued_for_destruction = True
-        self.clear_all_weakrefs()
-        if call_user_del:
-            space.user_del_action.register_dying_object(self)
-
-    def _call_builtin_destructor(self):
-        pass     # method overridden in typedef.py
+            self.__already_enqueued_for_destruction += (callback,)
+        space.user_del_action.register_callback(self, callback, descrname)
 
     # hooks that the mapdict implementations needs:
     def _get_mapdict_map(self):
diff --git a/pypy/interpreter/executioncontext.py b/pypy/interpreter/executioncontext.py
--- a/pypy/interpreter/executioncontext.py
+++ b/pypy/interpreter/executioncontext.py
@@ -484,44 +484,31 @@
 
     def __init__(self, space):
         AsyncAction.__init__(self, space)
-        self.dying_objects_w = []
-        self.weakrefs_w = []
+        self.dying_objects = []
         self.finalizers_lock_count = 0
 
-    def register_dying_object(self, w_obj):
-        self.dying_objects_w.append(w_obj)
-        self.fire()
-
-    def register_weakref_callback(self, w_ref):
-        self.weakrefs_w.append(w_ref)
+    def register_callback(self, w_obj, callback, descrname):
+        self.dying_objects.append((w_obj, callback, descrname))
         self.fire()
 
     def perform(self, executioncontext, frame):
         if self.finalizers_lock_count > 0:
             return
-        # Each call to perform() first grabs the self.dying_objects_w
+        # Each call to perform() first grabs the self.dying_objects
         # and replaces it with an empty list.  We do this to try to
         # avoid too deep recursions of the kind of __del__ being called
         # while in the middle of another __del__ call.
-        pending_w = self.dying_objects_w
-        self.dying_objects_w = []
+        pending = self.dying_objects
+        self.dying_objects = []
         space = self.space
-        for i in range(len(pending_w)):
-            w_obj = pending_w[i]
-            pending_w[i] = None
+        for i in range(len(pending)):
+            w_obj, callback, descrname = pending[i]
+            pending[i] = (None, None, None)
             try:
-                space.userdel(w_obj)
+                callback(w_obj)
             except OperationError, e:
-                e.write_unraisable(space, 'method __del__ of ', w_obj)
+                e.write_unraisable(space, descrname, w_obj)
                 e.clear(space)   # break up reference cycles
-            # finally, this calls the interp-level destructor for the
-            # cases where there is both an app-level and a built-in __del__.
-            w_obj._call_builtin_destructor()
-        pending_w = self.weakrefs_w
-        self.weakrefs_w = []
-        for i in range(len(pending_w)):
-            w_ref = pending_w[i]
-            w_ref.activate_callback()
 
 class FrameTraceAction(AsyncAction):
     """An action that calls the local trace functions (w_f_trace)."""
diff --git a/pypy/interpreter/generator.py b/pypy/interpreter/generator.py
--- a/pypy/interpreter/generator.py
+++ b/pypy/interpreter/generator.py
@@ -114,6 +114,7 @@
  
     def descr_close(self):
         """x.close(arg) -> raise GeneratorExit inside generator."""
+        assert isinstance(self, GeneratorIterator)
         space = self.space
         try:
             w_retval = self.throw(space.w_GeneratorExit, space.w_None,
@@ -141,22 +142,16 @@
         code_name = self.pycode.co_name
         return space.wrap(code_name)
 
-    def descr__del__(self):        
-        """
-        applevel __del__, which is called at a safe point after the
-        interp-level __del__ enqueued the object for destruction
-        """
-        self.descr_close()
-
     def __del__(self):
         # Only bother enqueuing self to raise an exception if the frame is
         # still not finished and finally or except blocks are present.
-        must_call_close = False
         if self.frame is not None:
             block = self.frame.lastblock
             while block is not None:
                 if not isinstance(block, LoopBlock):
-                    must_call_close = True
+                    self.clear_all_weakrefs()
+                    self.enqueue_for_destruction(self.space,
+                                                 GeneratorIterator.descr_close,
+                                                 "interrupting generator of ")
                     break
                 block = block.previous
-        self._enqueue_for_destruction(self.space, must_call_close)
diff --git a/pypy/interpreter/test/test_typedef.py b/pypy/interpreter/test/test_typedef.py
--- a/pypy/interpreter/test/test_typedef.py
+++ b/pypy/interpreter/test/test_typedef.py
@@ -1,3 +1,4 @@
+import gc
 from pypy.interpreter import typedef
 from pypy.tool.udir import udir
 from pypy.interpreter.baseobjspace import Wrappable
@@ -180,6 +181,85 @@
             assert err.value.message == "'some_type' objects are unhashable"
             """)
 
+    def test_destructor(self):
+        space = self.space
+        class W_Level1(Wrappable):
+            def __init__(self, space1):
+                assert space1 is space
+            def __del__(self):
+                space.call_method(w_seen, 'append', space.wrap(1))
+        class W_Level2(Wrappable):
+            def __init__(self, space1):
+                assert space1 is space
+            def __del__(self):
+                self.enqueue_for_destruction(space, W_Level2.destructormeth,
+                                             'FOO ')
+            def destructormeth(self):
+                space.call_method(w_seen, 'append', space.wrap(2))
+        W_Level1.typedef = typedef.TypeDef(
+            'level1',
+            __new__ = typedef.generic_new_descr(W_Level1))
+        W_Level2.typedef = typedef.TypeDef(
+            'level2',
+            __new__ = typedef.generic_new_descr(W_Level2))
+        #
+        w_seen = space.newlist([])
+        W_Level1(space)
+        gc.collect(); gc.collect()
+        assert space.unwrap(w_seen) == [1]
+        #
+        w_seen = space.newlist([])
+        W_Level2(space)
+        gc.collect(); gc.collect()
+        assert space.str_w(space.repr(w_seen)) == "[]"  # not called yet
+        ec = space.getexecutioncontext()
+        self.space.user_del_action.perform(ec, None)
+        assert space.unwrap(w_seen) == [2]
+        #
+        w_seen = space.newlist([])
+        self.space.appexec([self.space.gettypeobject(W_Level1.typedef)],
+        """(level1):
+            class A3(level1):
+                pass
+            A3()
+        """)
+        gc.collect(); gc.collect()
+        assert space.unwrap(w_seen) == [1]
+        #
+        w_seen = space.newlist([])
+        self.space.appexec([self.space.gettypeobject(W_Level1.typedef),
+                            w_seen],
+        """(level1, seen):
+            class A4(level1):
+                def __del__(self):
+                    seen.append(4)
+            A4()
+        """)
+        gc.collect(); gc.collect()
+        assert space.unwrap(w_seen) == [4, 1]
+        #
+        w_seen = space.newlist([])
+        self.space.appexec([self.space.gettypeobject(W_Level2.typedef)],
+        """(level2):
+            class A5(level2):
+                pass
+            A5()
+        """)
+        gc.collect(); gc.collect()
+        assert space.unwrap(w_seen) == [2]
+        #
+        w_seen = space.newlist([])
+        self.space.appexec([self.space.gettypeobject(W_Level2.typedef),
+                            w_seen],
+        """(level2, seen):
+            class A6(level2):
+                def __del__(self):
+                    seen.append(6)
+            A6()
+        """)
+        gc.collect(); gc.collect()
+        assert space.unwrap(w_seen) == [6, 2]
+
 
 class AppTestTypeDef:
 
diff --git a/pypy/interpreter/typedef.py b/pypy/interpreter/typedef.py
--- a/pypy/interpreter/typedef.py
+++ b/pypy/interpreter/typedef.py
@@ -228,21 +228,26 @@
                 return self._lifeline_
             def setweakref(self, space, weakreflifeline):
                 self._lifeline_ = weakreflifeline
+            def delweakref(self):
+                self._lifeline_ = None
         add(Proto)
 
     if "del" in features:
+        parent_destructor = getattr(supercls, '__del__', None)
+        def call_parent_del(self):
+            assert isinstance(self, subcls)
+            parent_destructor(self)
+        def call_applevel_del(self):
+            assert isinstance(self, subcls)
+            self.space.userdel(self)
         class Proto(object):
             def __del__(self):
-                self._enqueue_for_destruction(self.space)
-        # if the base class needs its own interp-level __del__,
-        # we override the _call_builtin_destructor() method to invoke it
-        # after the app-level destructor.
-        parent_destructor = getattr(supercls, '__del__', None)
-        if parent_destructor is not None:
-            def _call_builtin_destructor(self):
-                parent_destructor(self)
-            Proto._call_builtin_destructor = _call_builtin_destructor
-
+                self.clear_all_weakrefs()
+                self.enqueue_for_destruction(self.space, call_applevel_del,
+                                             'method __del__ of ')
+                if parent_destructor is not None:
+                    self.enqueue_for_destruction(self.space, call_parent_del,
+                                                 'internal destructor of ')
         add(Proto)
 
     if "slots" in features:
@@ -630,9 +635,12 @@
         return self._lifeline_
     def setweakref(self, space, weakreflifeline):
         self._lifeline_ = weakreflifeline
+    def delweakref(self):
+        self._lifeline_ = None
     cls._lifeline_ = None
     cls.getweakref = getweakref
     cls.setweakref = setweakref
+    cls.delweakref = delweakref
     return weakref_descr
 
 
@@ -858,8 +866,6 @@
                             descrmismatch='close'),
     __iter__   = interp2app(GeneratorIterator.descr__iter__,
                             descrmismatch='__iter__'),
-    __del__    = interp2app(GeneratorIterator.descr__del__,
-                            descrmismatch='__del__'),
     gi_running = interp_attrproperty('running', cls=GeneratorIterator),
     gi_frame   = GetSetProperty(GeneratorIterator.descr_gi_frame),
     gi_code    = GetSetProperty(GeneratorIterator.descr_gi_code),
diff --git a/pypy/module/_file/interp_file.py b/pypy/module/_file/interp_file.py
--- a/pypy/module/_file/interp_file.py
+++ b/pypy/module/_file/interp_file.py
@@ -43,11 +43,17 @@
         # assume that the file and stream objects are only visible in the
         # thread that runs __del__, so no race condition should be possible
         self.clear_all_weakrefs()
+        if self.stream is not None:
+            self.enqueue_for_destruction(self.space, W_File.destructor,
+                                         'close() method of ')
+
+    def destructor(self):
+        assert isinstance(self, W_File)
         try:
             self.direct_close()
         except StreamErrors, e:
             operr = wrap_streamerror(self.space, e, self.w_name)
-            operr.write_unraisable(self.space, '__del__ of ', self)
+            raise operr
 
     def fdopenstream(self, stream, fd, mode, w_name=None):
         self.fd = fd
diff --git a/pypy/module/_io/interp_iobase.py b/pypy/module/_io/interp_iobase.py
--- a/pypy/module/_io/interp_iobase.py
+++ b/pypy/module/_io/interp_iobase.py
@@ -57,6 +57,11 @@
 
     def __del__(self):
         self.clear_all_weakrefs()
+        self.enqueue_for_destruction(self.space, W_IOBase.destructor,
+                                     'internal __del__ of ')
+
+    def destructor(self):
+        assert isinstance(self, W_IOBase)
         space = self.space
         w_closed = space.findattr(self, space.wrap('closed'))
         try:
diff --git a/pypy/module/_weakref/interp__weakref.py b/pypy/module/_weakref/interp__weakref.py
--- a/pypy/module/_weakref/interp__weakref.py
+++ b/pypy/module/_weakref/interp__weakref.py
@@ -10,7 +10,7 @@
 
 class WeakrefLifeline(W_Root):
     def __init__(self, space):
-        self.space = space       # this is here for W_Root.clear_all_weakrefs()
+        self.space = space
         self.refs_weak = []
         self.cached_weakref_index = -1
         self.cached_proxy_index = -1
@@ -23,8 +23,10 @@
         """
         for i in range(len(self.refs_weak) - 1, -1, -1):
             w_ref = self.refs_weak[i]()
-            if w_ref is not None:
-                self.space.user_del_action.register_weakref_callback(w_ref)
+            if w_ref is not None and w_ref.w_callable is not None:
+                w_ref.enqueue_for_destruction(self.space,
+                                              W_WeakrefBase.activate_callback,
+                                              'weakref callback of ')
 
     def clear_all_weakrefs(self):
         """Clear all weakrefs.  This is called when an app-level object has
@@ -118,11 +120,8 @@
         self.w_obj_weak = dead_ref
 
     def activate_callback(w_self):
-        if not w_self.w_callable is None:
-            try:
-                w_self.space.call_function(w_self.w_callable, w_self)
-            except OperationError, e:
-                e.write_unraisable(w_self.space, 'weakref callback ', w_self.w_callable)
+        assert isinstance(w_self, W_WeakrefBase)
+        w_self.space.call_function(w_self.w_callable, w_self)
 
     def descr__repr__(self, space):
         w_obj = self.dereference()
diff --git a/pypy/objspace/std/mapdict.py b/pypy/objspace/std/mapdict.py
--- a/pypy/objspace/std/mapdict.py
+++ b/pypy/objspace/std/mapdict.py
@@ -431,12 +431,17 @@
             return None
         assert isinstance(lifeline, WeakrefLifeline)
         return lifeline
+    getweakref._cannot_really_call_random_things_ = True
 
     def setweakref(self, space, weakreflifeline):
         from pypy.module._weakref.interp__weakref import WeakrefLifeline
-        assert (isinstance(weakreflifeline, WeakrefLifeline) or
-                    weakreflifeline is None)
+        assert isinstance(weakreflifeline, WeakrefLifeline)
         self._get_mapdict_map().write(self, ("weakref", SPECIAL), weakreflifeline)
+    setweakref._cannot_really_call_random_things_ = True
+
+    def delweakref(self):
+        self._get_mapdict_map().write(self, ("weakref", SPECIAL), None)
+    delweakref._cannot_really_call_random_things_ = True
 
 class ObjectMixin(object):
     _mixin_ = True
diff --git a/pypy/objspace/std/setobject.py b/pypy/objspace/std/setobject.py
--- a/pypy/objspace/std/setobject.py
+++ b/pypy/objspace/std/setobject.py
@@ -36,6 +36,8 @@
         return self._lifeline_
     def setweakref(self, space, weakreflifeline):
         self._lifeline_ = weakreflifeline
+    def delweakref(self):
+        self._lifeline_ = None
 
 class W_SetObject(W_BaseSetObject):
     from pypy.objspace.std.settype import set_typedef as typedef
diff --git a/pypy/objspace/std/test/test_mapdict.py b/pypy/objspace/std/test/test_mapdict.py
--- a/pypy/objspace/std/test/test_mapdict.py
+++ b/pypy/objspace/std/test/test_mapdict.py
@@ -171,7 +171,7 @@
     obj = c.instantiate()
     assert obj.getweakref() is None
     obj.setweakref(space, lifeline1)
-    obj.setweakref(space, None)
+    obj.delweakref()
 
 
 
diff --git a/pypy/objspace/std/typeobject.py b/pypy/objspace/std/typeobject.py
--- a/pypy/objspace/std/typeobject.py
+++ b/pypy/objspace/std/typeobject.py
@@ -532,6 +532,8 @@
         return self._lifeline_
     def setweakref(self, space, weakreflifeline):
         self._lifeline_ = weakreflifeline
+    def delweakref(self):
+        self._lifeline_ = None
 
 # ____________________________________________________________
 # Initialization of type objects
diff --git a/pypy/rlib/jit.py b/pypy/rlib/jit.py
--- a/pypy/rlib/jit.py
+++ b/pypy/rlib/jit.py
@@ -482,6 +482,13 @@
                                    key[2:])
             cache[key] = s_value
 
+        # add the attribute _dont_reach_me_in_del_ (see pypy.rpython.rclass)
+        try:
+            graph = self.bookkeeper.position_key[0]
+            graph.func._dont_reach_me_in_del_ = True
+        except (TypeError, AttributeError):
+            pass
+
         return annmodel.s_None
 
     def annotate_hooks(self, **kwds_s):
diff --git a/pypy/rlib/test/test_jit.py b/pypy/rlib/test/test_jit.py
--- a/pypy/rlib/test/test_jit.py
+++ b/pypy/rlib/test/test_jit.py
@@ -83,6 +83,9 @@
 
         t, rtyper, fngraph = self.gengraph(fn, [int])
 
+        # added by compute_result_annotation()
+        assert fn._dont_reach_me_in_del_ == True
+
         def getargs(func):
             for graph in t.graphs:
                 if getattr(graph, 'func', None) is func:
diff --git a/pypy/rpython/lltypesystem/rclass.py b/pypy/rpython/lltypesystem/rclass.py
--- a/pypy/rpython/lltypesystem/rclass.py
+++ b/pypy/rpython/lltypesystem/rclass.py
@@ -400,6 +400,7 @@
                 assert len(s_func.descriptions) == 1
                 funcdesc, = s_func.descriptions
                 graph = funcdesc.getuniquegraph()
+                self.check_graph_of_del_does_not_call_too_much(graph)
                 FUNCTYPE = FuncType([Ptr(source_repr.object_type)], Void)
                 destrptr = functionptr(FUNCTYPE, graph.name,
                                        graph=graph,
diff --git a/pypy/rpython/rclass.py b/pypy/rpython/rclass.py
--- a/pypy/rpython/rclass.py
+++ b/pypy/rpython/rclass.py
@@ -374,6 +374,43 @@
     def can_ll_be_null(self, s_value):
         return s_value.can_be_none()
 
+    def check_graph_of_del_does_not_call_too_much(self, graph):
+        # RPython-level __del__() methods should not do "too much".
+        # In the PyPy Python interpreter, they usually do simple things
+        # like file.__del__() closing the file descriptor; or if they
+        # want to do more like call an app-level __del__() method, they
+        # enqueue the object instead, and the actual call is done later.
+        #
+        # Here, as a quick way to check "not doing too much", we check
+        # that from no RPython-level __del__() method we can reach a
+        # JitDriver.
+        #
+        # XXX wrong complexity, but good enough because the set of
+        # reachable graphs should be small
+        callgraph = self.rtyper.annotator.translator.callgraph.values()
+        seen = {graph: None}
+        while True:
+            oldlength = len(seen)
+            for caller, callee in callgraph:
+                if caller in seen and callee not in seen:
+                    func = getattr(callee, 'func', None)
+                    if getattr(func, '_dont_reach_me_in_del_', False):
+                        lst = [str(callee)]
+                        g = caller
+                        while g:
+                            lst.append(str(g))
+                            g = seen.get(g)
+                        lst.append('')
+                        raise TyperError("the RPython-level __del__() method "
+                                         "in %r calls:%s" % (
+                            graph, '\n\t'.join(lst[::-1])))
+                    if getattr(func, '_cannot_really_call_random_things_',
+                               False):
+                        continue
+                    seen[callee] = caller
+            if len(seen) == oldlength:
+                break
+
 # ____________________________________________________________
 
 def rtype_new_instance(rtyper, classdef, llops, classcallhop=None):
diff --git a/pypy/rpython/test/test_rclass.py b/pypy/rpython/test/test_rclass.py
--- a/pypy/rpython/test/test_rclass.py
+++ b/pypy/rpython/test/test_rclass.py
@@ -7,6 +7,7 @@
 from pypy.rpython.test.tool import BaseRtypingTest, LLRtypeMixin, OORtypeMixin
 from pypy.rpython.rclass import IR_IMMUTABLE, IR_IMMUTABLE_ARRAY
 from pypy.rpython.rclass import IR_QUASIIMMUTABLE, IR_QUASIIMMUTABLE_ARRAY
+from pypy.rpython.error import TyperError
 from pypy.objspace.flow.model import summary
 
 class EmptyBase(object):
@@ -1021,7 +1022,25 @@
         assert typeOf(destrptra).TO.ARGS[0] != typeOf(destrptrb).TO.ARGS[0]
         assert destrptra is not None
         assert destrptrb is not None
-        
+
+    def test_del_forbidden(self):
+        class A(object):
+            def __del__(self):
+                self.foo()
+            def foo(self):
+                self.bar()
+            def bar(self):
+                pass
+            bar._dont_reach_me_in_del_ = True
+        def f():
+            a = A()
+            a.foo()
+            a.bar()
+        t = TranslationContext()
+        t.buildannotator().build_types(f, [])
+        e = py.test.raises(TyperError, t.buildrtyper().specialize)
+        print e.value
+
     def test_instance_repr(self):
         from pypy.rlib.objectmodel import current_object_addr_as_int
         class FooBar(object):


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