Also SF patch 843455.
This is a critical bugfix.
I'll backport to 2.3 maint, but not beyond that. The bugs this fixes
have been there since weakrefs were introduced.
for this function has always claimed that was true, but it wasn't
verified before. For the latest batch of "double deallocation" bugs
(stemming from weakref callbacks invoked by way of subtype_dealloc),
this assert would have triggered (instead of waiting for
_Py_ForgetReference to die with a segfault later).
Formerly, underlying queue was implemented in terms of two lists. The
new queue is a series of singly-linked fixed length lists.
The new implementation runs much faster, supports multi-way tees, and
allows tees of tees without additional memory costs.
The root ideas for this structure were contributed by Andrew Koenig
and Guido van Rossum.
memory leak that would've occurred for all iterators that were
destroyed before having iterated until they raised StopIteration.
* Simplify some code.
* Add new test cases to check for the memleak and ensure that mixing
iteration with modification of the values for existing keys works.
has been closed" exceptions.
Adds a DBCursorClosedError exception in the closed cursor case for
future use in fixing the legacy bsddb interface deadlock problems
due to its use of cursors with DB_INIT_LOCK | DB_THREAD support
enabled.
* tee object is no longer subclassable
* independent iterators renamed to "itertools.tee_iterator"
* fixed doc string typo and added entry in the module doc string
* Add error checking code to PyList_Append() call.
* Replace PyObject_CallMethod(to->outbasket, "pop", NULL) with equivalent
in-line code. Inlining is important here because the search for the
pop method will occur for every element returned by the iterator.
* Make tee's dealloc() a little smarter. If the trailing iterator is
being deallocated, then the queue data is no longer needed and can
be freed.
It works like the pure python verion except:
* it stops storing data after of the iterators gets deallocated
* the data queue is implemented with two stacks instead of one dictionary.
