PEP 285. Everything described in the PEP is here, and there is even
some documentation. I had to fix 12 unit tests; all but one of these
were printing Boolean outcomes that changed from 0/1 to False/True.
(The exception is test_unicode.py, which did a type(x) == type(y)
style comparison. I could've fixed that with a single line using
issubtype(x, type(y)), but instead chose to be explicit about those
places where a bool is expected.
Still to do: perhaps more documentation; change standard library
modules to return False/True from predicates.
This displays stats about the # of arenas, pools, blocks and bytes, to
stderr, both used and reserved but unused.
CAUTION: Because PYMALLOC_DEBUG is on, the debug malloc routine adds
16 bytes to each request. This makes each block appear two size classes
higher than it would be if PYMALLOC_DEBUG weren't on.
So far, playing with this confirms the obvious: there's a lot of activity
in the "small dict" size class, but nothing in the core makes any use of
the 8-byte or 16-byte classes.
descriptor, as used for the tp_methods slot of a type. These new flag
bits are both optional, and mutually exclusive. Most methods will not
use either. These flags are used to create special method types which
exist in the same namespace as normal methods without having to use
tedious construction code to insert the new special method objects in
the type's tp_dict after PyType_Ready() has been called.
If METH_CLASS is specified, the method will represent a class method
like that returned by the classmethod() built-in.
If METH_STATIC is specified, the method will represent a static method
like that returned by the staticmethod() built-in.
These flags may not be used in the PyMethodDef table for modules since
these special method types are not meaningful in that case; a
ValueError will be raised if these flags are found in that context.
When WITH_PYMALLOC is defined, define PYMALLOC_DEBUG to enable the debug
allocator. This can be done independent of build type (release or debug).
A debug build automatically defines PYMALLOC_DEBUG when pymalloc is
enabled. It's a detected error to define PYMALLOC_DEBUG when pymalloc
isn't enabled.
Two debugging entry points defined only under PYMALLOC_DEBUG:
+ _PyMalloc_DebugCheckAddress(const void *p) can be used (e.g., from gdb)
to sanity-check a memory block obtained from pymalloc. It sprays
info to stderr (see next) and dies via Py_FatalError if the block is
detectably damaged.
+ _PyMalloc_DebugDumpAddress(const void *p) can be used to spray info
about a debug memory block to stderr.
A tiny start at implementing "API family" checks isn't good for
anything yet.
_PyMalloc_DebugRealloc() has been optimized to do little when the new
size is <= old size. However, if the new size is larger, it really
can't call the underlying realloc() routine without either violating its
contract, or knowing something non-trivial about how the underlying
realloc() works. A memcpy is always done in this case.
This was a disaster for (and only) one of the std tests: test_bufio
creates single text file lines up to a million characters long. On
Windows, fileobject.c's get_line() uses the horridly funky
getline_via_fgets(), which keeps growing and growing a string object
hoping to find a newline. It grew the string object 1000 bytes each
time, so for a million-character string it took approximately forever
(I gave up after a few minutes).
So, also:
fileobject.c, getline_via_fgets(): When a single line is outrageously
long, grow the string object at a mildly exponential rate, instead of
just 1000 bytes at a time.
That's enough so that a debug-build test_bufio finishes in about 5 seconds
on my Win98SE box. I'm curious to try this on Win2K, because it has very
different memory behavior than Win9X, and test_bufio always took a factor
of 10 longer to complete on Win2K. It *could* be that the endless
reallocs were simply killing it on Win2K even in the release build.
and not pymalloc. Add the functions PyMalloc_New, PyMalloc_NewVar, and
PyMalloc_Del that will use pymalloc if it's enabled. If pymalloc is
not enabled then they use the standard malloc (PyMem_*).
Windows some modules are considered (by me, and I don't care what anyone
else thinks about this <wink>) to be part of "the core" despite that they
happen to be compiled into separate DLLs (the "to DLL or not to DLL?"
question on Windows is nearly arbitrary). Making the pymalloc entry
points available to them allows the Windows build to complete without
incident when WITH_PYMALLOC is #define'd.
Note that this isn't unprecedented. Other "private API" functions we
export include _PySequence_IterSearch, _PyEval_SliceIndex, _PyCodec_Lookup,
_Py_ZeroStruct, _Py_TrueStruct, _PyLong_New and _PyModule_Clear.
Another year in the quest to out-guess random C behavior.
Added macros Py_ADJUST_ERANGE1(X) and Py_ADJUST_ERANGE2(X, Y). The latter
is useful for functions with complex results. Two corrections to errno-
after-libm-call are attempted:
1. If the platform set errno to ERANGE due to underflow, clear errno.
Some unknown subset of libm versions and link options do this. It's
allowed by C89, but I never figured anyone would do it.
2. If the platform did not set errno but overflow occurred, force
errno to ERANGE. C89 required setting errno to ERANGE, but C99
doesn't. Some unknown subset of libm versions and link options do
it the C99 way now.
Bugfix candidate, but hold off until some Linux people actually try it,
with and without -lieee. I'll send a help plea to Python-Dev.
platform realloc(p, 0) returns NULL, so MALLOC_ZERO_RETURNS_NULL can
be correctly undefined yet realloc(p, 0) can return NULL anyway.
Prevent realloc(p, 0) doing free(p) and returning NULL via a different
hack. Would probably be better to get rid of MALLOC_ZERO_RETURNS_NULL
entirely.
Bugfix candidate.
alignment gimmick. David Abrahams notes that the standard "long double"
actually requires stricter alignment than "double" on some Tru64 box.
On my box and yours <wink>, it's the same, so no harm done on most
boxes.
the first 3 characters of this string in several places, so for as long
as they remain "2.2" it confuses the heck out of attempts to build 2.3
stuff using distutils.
Removed the ancient "#define ANY void".
Bugfix candidate? Hard call. The bug report claims the existence of
this #define creates conflicts with other packages, which is easy to
believe. OTOH, some extension authors may still be relying on its
presence. I'm afraid you can't win on this one.
PyDict_UpdateFromSeq2(): removed it.
PyDict_MergeFromSeq2(): made it public and documented it.
PyDict_Merge() docs: updated to reveal <wink> that the second
argument can be any mapping object.
type.__module__ behavior.
This adds the module name and a dot in front of the type name in every
type object initializer, except for built-in types (and those that
already had this). Note that it touches lots of Mac modules -- I have
no way to test these but the changes look right. Apologies if they're
not. This also touches the weakref docs, which contains a sample type
object initializer. It also touches the mmap test output, because the
mmap type's repr is included in that output. It touches object.h to
put the correct description in a comment.
Big Hammer to implement -Qnew as PEP 238 says it should work (a global
option affecting all instances of "/").
pydebug.h, main.c, pythonrun.c: define a private _Py_QnewFlag flag, true
iff -Qnew is passed on the command line. This should go away (as the
comments say) when true division becomes The Rule. This is
deliberately not exposed to runtime inspection or modification: it's
a one-way one-shot switch to pretend you're using Python 3.
ceval.c: when _Py_QnewFlag is set, treat BINARY_DIVIDE as
BINARY_TRUE_DIVIDE.
test_{descr, generators, zipfile}.py: fiddle so these pass under
-Qnew too. This was just a matter of s!/!//! in test_generators and
test_zipfile. test_descr was trickier, as testbinop() is passed
assumptions that "/" is the same as calling a "__div__" method; put
a temporary hack there to call "__truediv__" instead when the method
name is "__div__" and 1/2 evaluates to 0.5.
Three standard tests still fail under -Qnew (on Windows; somebody
please try the Linux tests with -Qnew too! Linux runs a whole bunch
of tests Windows doesn't):
test_augassign
test_class
test_coercion
I can't stay awake longer to stare at this (be my guest). Offhand
cures weren't obvious, nor was it even obvious that cures are possible
without major hackery.
Question: when -Qnew is in effect, should calls to __div__ magically
change into calls to __truediv__? See "major hackery" at tail end of
last paragraph <wink>.
There's now a new structmember code, T_OBJECT_EX, which is used for
all __slot__ variables (except __weakref__, which has special behavior
anyway). This new code raises AttributeError when the variable is
NULL rather than converting NULL to None.
use wrappers on all platforms, to make this as consistent as possible x-
platform (in particular, make sure there's at least one \0 byte in
the output buffer). Also document more of the truth about what these do.
getargs.c, seterror(): Three computations of remaining buffer size were
backwards, thus telling PyOS_snprintf the buffer is larger than it
actually is. This matters a lot now that PyOS_snprintf ensures there's a
trailing \0 byte (because it didn't get the truth about the buffer size,
it was storing \0 beyond the true end of the buffer).
sysmodule.c, mywrite(): Simplify, now that PyOS_vsnprintf guarantees to
produce a \0 byte.
const char* instead of char*. The change is conceptually correct, and
indirectly fixes a compiler wng introduced when somebody else innocently
passed a const char* to this function.
RISCOS/Makefile:
include structseq and weakrefobject;
changes to keep command line length below 2048
RISCOS/Modules/riscosmodule.c:
typos from the stat structseq patch
Include/pyport.h:
don't re-#define __attribute__(__x) on RISC OS as it is already defined in c library
object.h: Added PyType_CheckExact macro.
typeobject.c, type_new():
+ Use the new macro.
+ Assert that the arguments have the right types rather than do incomplete
runtime checks "sometimes".
+ If this isn't the 1-argument flavor() of type, and there aren't 3 args
total, produce a "types() takes 1 or 3 args" msg before
PyArg_ParseTupleAndKeywords produces a "takes exactly 3" msg.
PyObject_CallFunctionObArgs() and PyObject_CallMethodObArgs() have the
advantage that no format strings need to be parsed. The CallMethod
variant also avoids creating a new string object in order to retrieve
a method from an object as well.
outer level, the iterator protocol is used for memory-efficiency (the
outer sequence may be very large if fully materialized); at the inner
level, PySequence_Fast() is used for time-efficiency (these should
always be sequences of length 2).
dictobject.c, new functions PyDict_{Merge,Update}FromSeq2. These are
wholly analogous to PyDict_{Merge,Update}, but process a sequence-of-2-
sequences argument instead of a mapping object. For now, I left these
functions file static, so no corresponding doc changes. It's tempting
to change dict.update() to allow a sequence-of-2-seqs argument too.
Also changed the name of dictionary's keyword argument from "mapping"
to "x". Got a better name? "mapping_or_sequence_of_pairs" isn't
attractive, although more so than "mosop" <wink>.
abstract.h, abstract.tex: Added new PySequence_Fast_GET_SIZE function,
much faster than going thru the all-purpose PySequence_Size.
libfuncs.tex:
- Document dictionary().
- Fiddle tuple() and list() to admit that their argument is optional.
- The long-winded repetitions of "a sequence, a container that supports
iteration, or an iterator object" is getting to be a PITA. Many
months ago I suggested factoring this out into "iterable object",
where the definition of that could include being explicit about
generators too (as is, I'm not sure a reader outside of PythonLabs
could guess that "an iterator object" includes a generator call).
- Please check my curly braces -- I'm going blind <0.9 wink>.
abstract.c, PySequence_Tuple(): When PyObject_GetIter() fails, leave
its error msg alone now (the msg it produces has improved since
PySequence_Tuple was generalized to accept iterable objects, and
PySequence_Tuple was also stomping on the msg in cases it shouldn't
have even before PyObject_GetIter grew a better msg).
STRICT_SYSV_CURSES when compiling curses module on HP/UX. Generalize
access to _flags on systems where WINDOW is opaque. Fixes bugs
#432497, #422265, and the curses parts of #467145 and #473150.
'slotdef' structure typedef and 'struct wrapperbase'. By adding the
wrapper docstrings to the slotdef structure, the slotdefs array can
serve as the data structure that drives add_operators(); the wrapper
descriptor contains a pointer to slotdef structure. This replaces
lots of custom code from add_operators() by a loop over the slotdefs
array, and does away with all the tab_xxx tables.
This patch implements what we have discussed on python-dev late in
September: str(obj) and unicode(obj) should behave similar, while
the old behaviour is retained for unicode(obj, encoding, errors).
The patch also adds a new feature with which objects can provide
unicode(obj) with input data: the __unicode__ method. Currently no
new tp_unicode slot is implemented; this is left as option for the
future.
Note that PyUnicode_FromEncodedObject() no longer accepts Unicode
objects as input. The API name already suggests that Unicode
objects do not belong in the list of acceptable objects and the
functionality was only needed because
PyUnicode_FromEncodedObject() was being used directly by
unicode(). The latter was changed in the discussed way:
* unicode(obj) calls PyObject_Unicode()
* unicode(obj, encoding, errors) calls PyUnicode_FromEncodedObject()
One thing left open to discussion is whether to leave the
PyUnicode_FromObject() API as a thin API extension on top of
PyUnicode_FromEncodedObject() or to turn it into a (macro) alias
for PyObject_Unicode() and deprecate it. Doing so would have some
surprising consequences though, e.g. u"abc" + 123 would turn out
as u"abc123"...
[Marc-Andre didn't have time to check this in before the deadline. I
hope this is OK, Marc-Andre! You can still make changes and commit
them on the trunk after the branch has been made, but then please mail
Barry a context diff if you want the change to be merged into the
2.2b1 release branch. GvR]
This is a big one, touching lots of files. Some of the platforms
aren't tested yet. Briefly, this changes the return value of the
os/posix functions stat(), fstat(), statvfs(), fstatvfs(), and the
time functions localtime(), gmtime(), and strptime() from tuples into
pseudo-sequences. When accessed as a sequence, they behave exactly as
before. But they also have attributes like st_mtime or tm_year. The
stat return value, moreover, has a few platform-specific attributes
that are not available through the sequence interface (because
everybody expects the sequence to have a fixed length, these couldn't
be added there). If your platform's struct stat doesn't define
st_blksize, st_blocks or st_rdev, they won't be accessible from Python
either.
(Still missing is a documentation update.)
This changes Pythread_start_thread() to return the thread ID, or -1
for an error. (It's technically an incompatible API change, but I
doubt anyone calls it.)
"for <var> in <testlist> may no longer be a single test followed by
a comma. This solves SF bug #431886. Note that if the testlist
contains more than one test, a trailing comma is still allowed, for
maximum backward compatibility; but this example is not:
[(x, y) for x in range(10), for y in range(10)]
^
The fix involved creating a new nonterminal 'testlist_safe' whose
definition doesn't allow the trailing comma if there's only one test:
testlist_safe: test [(',' test)+ [',']]
The platform requires 8-byte alignment for doubles, but the GC header
was 12 bytes and that threw off the natural alignment of the double
members of a subtype of complex. The fix puts the GC header into a
union with a double as the other member, to force no-looser-than
double alignment of GC headers. On boxes that require 8-byte alignment
for doubles, this may add pad bytes to the GC header accordingly; ditto
for platforms that *prefer* 8-byte alignment for doubles. On platforms
that don't care, it shouldn't change the memory layout (because the
size of the old GC header is certainly greater than the size of a double
on all platforms, so unioning with a double shouldn't change size or
alignment on such boxes).
is a list of weak references to types (new-style classes). Make this
accessible to Python as the function __subclasses__ which returns a
list of types -- we don't want Python programmers to be able to
manipulate the raw list.
In order to make this possible, I also had to add weak reference
support to type objects.
This will eventually be used together with a trap on attribute
assignment for dynamic classes for a major speed-up without losing the
dynamic properties of types: when a __foo__ method is added to a
class, the class and all its subclasses will get an appropriate tp_foo
slot function.
This simplifies the rounding in _PyObject_VAR_SIZE, allows to restore the
pre-rounding calling sequence, and allows some nice little simplifications
in its callers. I'm still making it return a size_t, though.
As Guido suggested, this makes the new subclassing code substantially
simpler. But the mechanics of doing it w/ C macro semantics are a mess,
and _PyObject_VAR_SIZE has a new calling sequence now.
Question: The PyObject_NEW_VAR macro appears to be part of the public API.
Regardless of what it expands to, the notion that it has to round up the
memory it allocates is new, and extensions containing the old
PyObject_NEW_VAR macro expansion (which was embedded in the
PyObject_NEW_VAR expansion) won't do this rounding. But the rounding
isn't actually *needed* except for new-style instances with dict pointers
after a variable-length blob of embedded data. So my guess is that we do
not need to bump the API version for this (as the rounding isn't needed
for anything an extension can do unless it's recompiled anyway). What's
your guess?
pad memory to properly align the __dict__ pointer in all cases.
gcmodule.c/objimpl.h, _PyObject_GC_Malloc:
+ Added a "padding" argument so that this flavor of malloc can allocate
enough bytes for alignment padding (it can't know this is needed, but
its callers do).
typeobject.c, PyType_GenericAlloc:
+ Allocated enough bytes to align the __dict__ pointer.
+ Sped and simplified the round-up-to-PTRSIZE logic.
+ Added blank lines so I could parse the if/else blocks <0.7 wink>.
test dramatically:
class T(tuple): __dynamic__ = 1
t = T(range(1000))
for i in range(1000): tt = tuple(t)
The speedup was about 5x compared to the previous state of CVS (1.7
vs. 8.8, in arbitrary time units). But it's still more than twice as
slow as as the same test with __dynamic__ = 0 (0.8).
I'm not sure that I really want to go through the trouble of this kind
of speedup for every slot. Even doing it just for the most popular
slots will be a major effort (the new slot_sq_item is 40+ lines, while
the old one was one line with a powerful macro -- unfortunately the
speedup comes from expanding the macro and doing things in a way
specific to the slot signature).
An alternative that I'm currently considering is sketched in PLAN.txt:
trap setattr on type objects. But this will require keeping track of
all derived types using weak references.
instances).
Also added GC support to various auxiliary types: super, property,
descriptors, wrappers, dictproxy. (Only type objects have a tp_clear
field; the other types are.)
One change was necessary to the GC infrastructure. We have statically
allocated type objects that don't have a GC header (and can't easily
be given one) and heap-allocated type objects that do have a GC
header. Giving these different metatypes would be really ugly: I
tried, and I had to modify pickle.py, cPickle.c, copy.py, add a new
invent a new name for the new metatype and make it a built-in, change
affected tests... In short, a mess. So instead, we add a new type
slot tp_is_gc, which is a simple Boolean function that determines
whether a particular instance has GC headers or not. This slot is
only relevant for types that have the (new) GC flag bit set. If the
tp_is_gc slot is NULL (by far the most common case), all instances of
the type are deemed to have GC headers. This slot is called by the
PyObject_IS_GC() macro (which is only used twice, both times in
gcmodule.c).
I also changed the extern declarations for a bunch of GC-related
functions (_PyObject_GC_Del etc.): these always exist but objimpl.h
only declared them when WITH_CYCLE_GC was defined, but I needed to be
able to reference them without #ifdefs. (When WITH_CYCLE_GC is not
defined, they do the same as their non-GC counterparts anyway.)
The patch repaired internal gcc compiler errors on BeOS.
This checkin repairs them in a simpler way, by explicitly casting the
platform INFINITY to double.
no backwards compatibility to worry about, so I just pushed the
'closure' struct member to the back -- it's never used in the current
code base (I may eliminate it, but that's more work because the getter
and setter signatures would have to change.)
As examples, I added actual docstrings to the getset attributes of a
few types: file.closed, xxsubtype.spamdict.state.
compatibility, this required all places where an array of "struct
memberlist" structures was declared that is referenced from a type's
tp_members slot to change the type of the structure to PyMemberDef;
"struct memberlist" is now only used by old code that still calls
PyMember_Get/Set. The code in PyObject_GenericGetAttr/SetAttr now
calls the new APIs PyMember_GetOne/SetOne, which take a PyMemberDef
argument.
As examples, I added actual docstrings to the attributes of a few
types: file, complex, instance method, super, and xxsubtype.spamlist.
Also converted the symtable to new style getattr.
hack, and it's even more disgusting than a PyInstance_Check() call.
If the tp_compare slot is the slot used for overrides in Python,
it's always called.
Add some tests that show what should work too.
Renamed the 'readonly' field to 'flags' and defined some new flag
bits: READ_RESTRICTED and WRITE_RESTRICTED, as well as a shortcut
RESTRICTED that means both.
tuple(i) repaired to return a true tuple when i is an instance of a
tuple subclass.
Added PyTuple_CheckExact macro.
PySequence_Tuple(): if a tuple-like object isn't exactly a tuple, it's
not safe to return the object as-is -- make a new tuple of it instead.
Given an immutable type M, and an instance I of a subclass of M, the
constructor call M(I) was just returning I as-is; but it should return a
new instance of M. This fixes it for M in {int, long}. Strings, floats
and tuples remain to be done.
Added new macros PyInt_CheckExact and PyLong_CheckExact, to more easily
distinguish between "is" and "is a" (i.e., only an int passes
PyInt_CheckExact, while any sublass of int passes PyInt_Check).
Added private API function _PyLong_Copy.
Guido van Rossum
Tim Peters
Martin v. Löwis
Neil Schemenauer
Fred Drake
Neal Norwitz
Andrew M. Kuchling
Jeremy Hylton
Andrew MacIntyre
Jack Jansen
Barry Warsaw
Marc-André Lemburg