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lib/tests/test_zodb.py

@@ -310,138 +310,6 @@ def test_zconn_at():
     assert zconn_at(conn_at0) == at0
 
 
-# verify that zconn_at is robust wrt races.
-# see e.g.
-# - https://github.com/zopefoundation/ZODB/issues/290
-# - https://github.com/zopefoundation/ZODB/pull/307#discussion_r434145034
-# - https://github.com/zopefoundation/ZEO/issues/155
-# for what kind of data corruption issues might be there.
-@xfail(zmajor < 4, reason="zconn_at is TODO for ZODB3")
-@func
-def test_zconn_at_vs_races():
-    # XXX doc
-    stor0 = testdb.getZODBStorage()
-    db0   = DB(stor0)
-    defer(db0.close)
-
-    def dbopen():
-        # in ZODB/py FileStorage does not support opening the database from several clients
-        if isinstance(stor0, FileStorage):
-            return db0
-
-        stor = testdb.getZODBStorage()
-        db = DB(stor)
-        return db
-
-    def dbclose(db):
-        # see ^^^ about FileStorage
-        if db is db0:
-            return
-        db.close()
-
-    # init the database with two integer objects - obj1/obj2 that are set to 0.
-    @func
-    def _():
-        db = dbopen()
-        defer(lambda: dbclose(db))
-
-        transaction.begin()
-        conn = db.open()
-
-        root = conn.root()
-        root['obj1'] = XInt(0)
-        root['obj2'] = XInt(0)
-
-        transaction.commit()
-        conn.close()
-    _()
-
-
-    # T is a worker that accesses obj1/obj2 in a loop and verifies
-    # `obj1.i == obj2.i` invariant.
-    #
-    # access to obj1 is organized to go through zconn.
-    # access to obj2 goes through zconn2 that is opened with at=zconn_at(zconn).
-    #
-    # this verifies that at=zconn_at(zconn) is consistent with database state observed by zconn.
-    #
-    # Once in a while T tries to modify obj{1,2}.i maintaining the invariant as
-    # test source of changes for other workers.
-    @func
-    def T(ctx, name, N):
-        db = dbopen()
-        defer(lambda: dbclose(db))
-
-        @func
-        def t1():
-            transaction.begin()
-            zconn = db.open()
-            defer(zconn.close)
-
-            tm2 = TransactionManager()
-            at = zconn_at(zconn)
-            zconn2 = db.open(at=at, transaction_manager=tm2)
-            defer(zconn2.close)
-            defer(tm2.abort)
-
-            root = zconn.root()
-            obj1 = root['obj1']
-
-            root2 = zconn2.root()
-            obj2_ = root['obj2']
-            #obj2_._p_invalidate()
-
-            # both objects must have the same values (zconn vs zconn2)
-            i1  = obj1.i
-            i2_ = obj2_.i
-            if i1 != i2_:
-                raise AssertionError("T%s: obj1.i (%d)  !=  obj2_.i (%d)" % (name, i1, i2_))
-
-            # ----//---- (zconn vs zconn)
-            obj2 = root['obj2']
-            i2 = obj2.i
-            if i1 != i2:
-                raise AssertionError("T%s: obj1.i (%d)  !=  obj2.i (%d)" % (name, i1, i2))
-
-            # change objects once in a while
-            if randint(0,4) == 0:
-                #print("T%s: modify" % name)
-                obj1.i += 1
-                obj2.i += 1
-
-            # verify that zconn_at result stays the same during lifetime of one transaction
-            at_ = zconn_at(zconn)
-            if at_ != at:
-                raise AssertionError("T%s: at_ (%r)  !=  at (%r)" % (name, at_, at))
-            assert at_ == at
-
-            try:
-                transaction.commit()
-            except POSException.ConflictError:
-                #print('conflict -> ignore')
-                transaction.abort()
-
-        for i in range(N):
-            e = ctx.err()
-            if e is not None:
-                raise e
-            #print('T%s.%d' % (name, i))
-            t1()
-
-
-    # run 8 T workers concurrently. As of 20200123, likely due to race conditions   XXX
-    # in ZEO, it triggers the bug where T sees stale obj2 with obj1.i != obj2.i
-
-    N = 1000
-    wg = sync.WorkGroup(context.background())
-    for x in range(8):
-        wg.go(T, x, N)
-    wg.wait()
-
-    print('OK')
-
-
-
 # verify that ZODB.Connection.onResyncCallback works
 @xfail(zmajor < 4, reason="ZODB.Connection.onResyncCallback is TODO for ZODB3")
 @func