the code so that the most frequent cases come first. Added comments.
Found a hidden assumption that a pool contains room for at least two
blocks, and added an assert to catch a violation if it ever happens in
a place where that matters. Gave the normal "I allocated this block"
case a longer basic block to work with before it has to do its first
branch (via breaking apart an embedded assignment in an "if", and
hoisting common code out of both branches).
address obtained from system malloc/realloc without holding the GIL.
When the vector of arena base addresses has to grow, the old vector is
deliberately leaked. This makes "stale" x-thread references safe.
arenas and narenas are also declared volatile, and changed in an order
that prevents a thread from picking up a value of narenas too large
for the value of arenas it sees.
Added more asserts.
Fixed an old inaccurate comment.
Added a comment explaining why it's safe to call pymalloc free/realloc
with an address obtained from system malloc/realloc even when arenas is
still NULL (this is obscure, since the ADDRESS_IN_RANGE macro
appears <wink> to index into arenas).
this. But added an overflow check just in case there is.
Got rid of the ushort macro. It wasn't used anymore (it was only used
in the no-longer-exists off_t macro), and there's no plausible use for it.
waste the first pool if malloc happens to return a pool-aligned address.
This means the number of pools per arena can now vary by 1. Unfortunately,
the code counted up from 0 to a presumed constant number of pools. So
changed the increasing "watermark" counter to a decreasing "nfreepools"
counter instead, and fiddled various stuff accordingly. This also allowed
getting rid of two more macros.
Also changed the code to align the first address to a pool boundary
instead of a page boundary. These are two parallel sets of macro #defines
that happen to be identical now, but the page macros are in theory more
restrictive (bigger), and there's simply no reason I can see that it
wasn't aligning to the less restrictive pool size all along (the code
only relies on pool alignment).
Hmm. The "page size" macros aren't used for anything *except* defining
the pool size macros, and the comments claim the latter isn't necessary.
So this has the feel of a layer of indirection that doesn't serve a
purpose; should probably get rid of the page macros now.
are called without the GIL. It's incredibly unlikely to fail, but I can't
make this bulletproof without either adding a lock for exclusion, or
giving up on growing the arena base-address vector (it would be safe if
this were a static array).
+ A new scheme for determining whether an address belongs to a pymalloc
arena. This should be 100% reliable. The poolp->pooladdr and
poolp->magic members are gone. A new poolp->arenaindex member takes
their place. Note that the pool header overhead doesn't actually
shrink, though, since the header is padded to a multiple of 8 bytes.
+ _PyMalloc_Free and _PyMalloc_Realloc should now be safe to call for
any legit address, whether obtained from a _PyMalloc function or from
the system malloc/realloc. It should even be safe to call
_PyMalloc_Free when *not* holding the GIL, provided that the passed-in
address was obtained from system malloc/realloc. Since this is
accomplished without any locks, you better believe the code is subtle.
I hope it's sufficiently commented.
+ The above implies we don't need the new PyMalloc_{New, NewVar, Del}
API anymore, and could switch back to PyObject_XXX without breaking
existing code mixing PyObject_XXX with PyMem_{Del, DEL, Free, FREE}.
Nothing is done here about that yet, and I'd like to see this new
code exercised more first.
+ The small object threshhold is boosted to 256 (the max). We should
play with that some more, but the old 64 was way too small for 2.3.
+ Getting a new arena is now done via new function new_arena().
+ Removed some unused macros, and squashed out some macros that were
used only once to define other macros.
+ Arenas are no longer linked together. A new vector of arena base
addresses had to be created anyway to make address classification
bulletproof.
+ A lot of the patch size is an illusion: given the way address
classification works now, it was more convenient to switch the
sense of the prime "if" tests in the realloc and free functions,
so the "if" and "else" blocks got swapped.
+ Assorted minor code, comment and whitespace cleanup.
Back to the Windows installer <wink>.
(if a single newline convention is used in the sourcefile), and the
"save options" has a newline style radio button.
The creator radio button also has the new choices PythonW and None.
Just: just shout (and revert) if you don't agree.
Added a -D flag (can really only be specified on OSX commandline) to not
revector sys.stderr, for debugging the IDE itself. Not sure whether
this should stay.
return None.
For now, if the user asks for TEXT files files without type are also
accepted. But it is time to phase out StandardGetFile and friends, really.
Walter Doerwald provided a patch, which I've modified in two ways:
1) (Uncontroversial) Removed code to make module work in earlier versions of
Python without the unicode() built-in
2) (Poss. controversial) Instead of making string.zfill take the repr()
of non-string objects, take the str().
Should a warning be added to this branch of the code so that the automatic
str() can be deprecated?
2.2.2 bugfix candidate, assuming the repr()->str() change is deemed OK.
Neal Norwitz
Tim Peters
Jack Jansen
Martin v. Löwis
Fred Drake
Just van Rossum
Neil Schemenauer
Andrew M. Kuchling