subtype_dealloc(): This left the dying object exposed to gc, so that
if cyclic gc triggered during the weakref callback, gc tried to delete
the dying object a second time. That's a disaster. subtype_dealloc()
had a (I hope!) unique problem here, as every normal dealloc routine
untracks the object (from gc) before fiddling with weakrefs etc. But
subtype_dealloc has obscure technical reasons for re-registering the
dying object with gc (already explained in a large comment block at
the bottom of the function).
The fix amounts to simply refraining from reregistering the dying object
with gc until after the weakref callback (if any) has been called.
This is a critical bug (hard to predict, and causes seemingly random
memory corruption when it occurs). I'll backport it to 2.3 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.
* 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
charmaptranslate_makespace() allocated more memory than required for the
next replacement but didn't remember that fact, so memory size was growing
exponentially every time a replacement string is longer that one character.
This fixes SF bug #828737.
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.
key provides C support for the decorate-sort-undecorate pattern.
reverse provide a stable sort of the list with the comparisions reversed.
* Amended the docs to guarantee sort stability.
* Added C coded getrandbits(k) method that runs in linear time.
* Call the new method from randrange() for ranges >= 2**53.
* Adds a warning for generators not defining getrandbits() whenever they
have a call to randrange() with too large of a population.
is None, the next row read is used as the fieldnames. In the common case,
this means the programmer doesn't need to know the fieldnames ahead of time.
The first row of the file will be used. In the uncommon case, this means
the programmer can set the reader's fieldnames attribute to None at any time
and have the next row read as the next set of fieldnames, so a csv file can
contain several "sections", each with different fieldnames.
why in a new comment. My home Win98SE box is one of the "real systems"
alluded to (my system "default sound" appears to have vanished sometime
in the last month, that's certainly not a Python bug, and the MS
PlaySound docs are correct in their explanation of what happens then).
Bugfix candidate. If someone can still sneak it into 2.3.1, that would
be good.
test_bad_address(): Recover from that VeriSign thought it would boost
its corporate coffers to start resolving http://www.sadflkjsasadf.com/.
Bugfix candidate -- although the bug is more VeriSign's than Python's!
Add support for the iterator and mapping protocols.
For Py2.3, this was done for shelve, dumbdbm and other mapping objects, but
not for bsddb and dbhash which were inadvertently missed.
file_truncate(): C doesn't define what fflush(fp) does if fp is open
for update, and the preceding I/O operation on fp was input. On Windows,
fflush() actually changes the current file position then. Because
Windows doesn't support ftruncate() directly, this not only caused
Python's file.truncate() to change the file position (contra our docs),
it also caused the file not to change size.
Repaired by getting the initial file position at the start, restoring
it at the end, and tossing all the complicated micro-efficiency checks
trying to avoid "provably unnecessary" seeks. file.truncate() can't
be a frequent operation, and seeking to the current file position has
got to be cheap anyway.
Bugfix candidate.
random.sample() uses one of two algorithms depending on the ratio of the
sample size to the population size. One of the algorithms accepted any
iterable population argument so long as it defined __len__(). The other
had a stronger requirement that the population argument be indexable.
While it met the documentation specifications which insisted that the
population argument be a sequence, it made random.sample() less usable
with sets. So, the second algorithm was modified to coerce non-indexable
iterables and dictionaries into a tuple before proceeding.
