in struct tm, time.struct_time objects returned by time.gmtime(),
time.localtime() and time.strptime() functions now have tm_zone and
tm_gmtoff attributes. Original patch by Paul Boddie.
Fix also its value on Windows and Linux according to its documentation:
"adjustable" indicates if the clock *can be* adjusted, not if it is or was
adjusted.
In most cases, it is not possible to indicate if a clock is or was adjusted.
2) Abort the loop for all specials, not only infinity.
3) Make the function more general and distinguish between zero clamping
and folding down the exponent. The latter case is currently handled
by setting context->clamp to 0 before calling the function.
2) Add rigorous error analysis to _mpd_qlog10 (ACL2 proofs exist).
3) Use the relative error as a basis for the interval generation in the
correction loop (same as in _mpd_qln()).
List all of them in the comment.
2) Use the recently stated relative error of _mpd_qln() to generate the
interval for the exact value of ln(x). See also the comment in mpd_qexp().
open() and io.TextIOWrapper are now calling locale.getpreferredencoding(False)
instead of locale.getpreferredencoding() in text mode if the encoding is not
specified. Don't change temporary the locale encoding using locale.setlocale(),
use the current locale encoding instead of the user preferred encoding.
Explain also in open() documentation that locale.getpreferredencoding(False) is
called if the encoding is not specified.
Underflow to zero hasn't changed: _mpd_qexp() internally uses MIN_EMIN,
so the result would also underflow to zero for all emin > MIN_EMIN.
In case digits are left, the informal argument is as follows: Underflow can
occur only once in the last multiplication of the power stage (in the Horner
stage Underflow provably cannot occur, and if Underflow occurred twice in
the power stage, the result would underflow to zero on the second occasion).
Since there is no double rounding during Underflow, the effective work
precision is now 1 <= result->digits < prec. It can be shown by a somewhat
tedious argument that abs(result - e**x) < ulp(result, result->digits).
Therefore the correct rounding loop now uses ulp(result, result->digits)
to generate the bounds for e**x in case of Underflow.
An issue in ctypes.c_longdouble, ctypes.c_double, and ctypes.c_float that
caused an incorrect exception to be returned in the case of overflow has been
fixed.
An issue in ctypes.c_longdouble, ctypes.c_double, and ctypes.c_float that
caused an incorrect exception to be returned in the case of overflow has been
fixed.
-----------------------
1) Reduce the number of iterations in the Horner scheme for operands with
a negative adjusted exponent. Previously the number was overestimated
quite generously.
2) The function _mpd_get_exp_iterations() now has an ACL2 proof and
is rewritten accordingly.
3) The proof relies on abs(op) > 9 * 10**(-prec-1), so operands without
that property are now handled by the new function _mpd_qexp_check_one().
4) The error analysis for the evaluation of the truncated Taylor series
in Hull&Abrham's paper relies on the fact that the reduced operand
'r' has fewer than context.prec digits.
Since the operands may have more than context.prec digits, a new ACL2
proof covers the case that r.digits > context.prec. To facilitate the
proof, the Horner step now uses fma instead of rounding twice in
multiply/add.
Changes in mpd_qexp():
----------------------
1) Fix a bound in the correct rounding loop that was too optimistic. In
practice results were always correctly rounded, because it is unlikely
that the error in _mpd_qexp() ever reaches the theoretical maximum.
Removed futimens as it is now redundant.
Changed shutil.copystat to use st_atime_ns and st_mtime_ns from os.stat
and ns= parameter to utime--it once again preserves exact metadata on Linux!
* Rename time.steady() to time.monotonic()
* On Windows, time.monotonic() uses GetTickCount/GetTickCount64() instead of
QueryPerformanceCounter()
* time.monotonic() uses CLOCK_HIGHRES if available
* Add time.get_clock_info(), time.perf_counter() and time.process_time()
functions
* In debug mode, fill the string data with invalid characters
* Simplify also reference counting in PyCodec_BackslashReplaceErrors()
and PyCodec_XMLCharRefReplaceError()
1) Rename _mpd_qbarrett_divmod into _mpd_base_ndivmod: The function is
only marginally related to either Barrett's algorithm or to the version
in Hasselstrom's paper.
2) In places where the proof assumes exact operations, use new versions of
add/sub/multiply that set NaN/Invalid_operation if this condition is
not met. According to the proof this cannot happen, so this should be
regarded as an extra safety net.
3) Raise Division_impossible for operands with a number of digits greater
than MPD_MAX_PREC. This facilitates the audit of the function and can
practically only occur in the 32-bit version under conditions where
a MemoryError is already imminent.
4) Use _mpd_qmul() in places where the result can exceed MPD_MAX_PREC in
a well defined manner.
5) Test for mpd_isspecial(qq) in a place where the addition of one
can theoretically trigger a Malloc_error.
6) Remove redundant code in _mpd_qdivmod().
7) Add many comments.
rightfully states that an mpd_t with a coefficient flagged as MPD_CONST_DATA
must not be in the position of the result operand. In this particular case
several assumptions guarantee that a resize will never occur in all possible
code paths, which was the reason for using MPD_CONST_DATA and saving an
instruction by omitting the initialization of tmp.alloc.
For readability, tmp is now flagged as MPD_STATIC_DATA and tmp.alloc
is initialized.
rewriting functionality in pure Python.
To start, imp.new_module() has been rewritten in pure Python, put into
importlib (privately) and then publicly exposed in imp.
Resizing is used _inside_ libmpdec functions, and it is permitted to
change x->alloc several times while setting x->len at the end of the
function. Therefore, for dynamic mpd_t x->alloc can _temporarily_ drop
below x->len. Of course the final result always has x->len <= x->alloc.
For static mpd_t this cannot happen, since resizing to a smaller
coefficient is a no-op.
2) Remove micro optimization in mpd_switch_to_dyn(): Previously only the
valid initialized part of the existing coefficient up to x->len was
copied to the new dynamic memory area. Now copying does the same as
realloc() and the entire old memory area is copied.
The rationale for this change is that it is no longer needed to memorize
the explanation given in 1).
2) Assert that the source operand is not special. Prevent resulting assert
failure (harmless) by initializing flags before calling mpd_qshiftr_inplace.
3) Save a couple of instructions (mpd_zerocoeff already sets digits and len).
Reorder initialization to match the order in the mpd_t struct.
in libmpdec to prevent undefined behavior if an invalid context is used. This
cannot occur for the _decimal module since user input for the context is
validated.
Unlike the other facilities, we don't use a fallback for AUTHPRIV if it
doesn't exist. Because it is intended for logging sensitive log messages, it
is better that a program trying to log such messages fail than that it log
them insecurely.
Initial patch by Federico Reghenzani.
clock_gettime(CLOCK_REALTIME) has a better resolution than gettimeofday().
time.time() falls back on gettimeofday() (and then on other functions) on
error.
with decimal.py. The standard specifies InsufficientStorage (MallocError) as
a sub-condition of InvalidOperation. This allows a calculation to continue
with NaN results when allocation fails.
append, extend and insert now consistently type-check their argument in both
the C and Python implementations, and raise TypeError for non-Element
argument.
Added tests
They're optional-only for now (unlike in pure Python) but that's all
I needed. The syntax can easily be relaxed if we want to support
required keyword-only arguments for extension types in the future.
consistent to the one raised by the Python module (the 'code' attribute
was added).
In addition, the exception is now documented.
Added a test to check that ParseError has the required attributes, and
threw away the equivalent doctest which is no longer required.
* On Mac OS X, time.steady() now uses mach_absolute_time(), a monotonic clock
* Optimistic change: bet that CLOCK_MONOTONIC and CLOCK_REALTIME are available
when clock_gettime() is available
* Rewrite time.steady() documentation
in the hash table internal to the pyexpat module's copy of the expat
library to avoid a denial of service due to hash collisions.
Patch by David Malcolm with some modifications by the expat project.
in the hash table internal to the pyexpat module's copy of the expat
library to avoid a denial of service due to hash collisions.
Patch by David Malcolm with some modifications by the expat project.
in the hash table internal to the pyexpat module's copy of the expat
library to avoid a denial of service due to hash collisions.
Patch by David Malcolm with some modifications by the expat project.
time.ctime(), gmtime(), time.localtime(), datetime.date.fromtimestamp(),
datetime.datetime.fromtimestamp() and datetime.datetime.utcfromtimestamp() now
raises an OverflowError, instead of a ValueError, if the timestamp does not fit
in time_t.
datetime.datetime.fromtimestamp() and datetime.datetime.utcfromtimestamp() now
round microseconds towards zero instead of rounding to nearest with ties going
away from zero.
Also, add a multiprocessing.connection.wait(rlist, timeout=None) function
for polling multiple objects at once. Patch by sbt.
Complete changelist from sbt's patch:
* Adds a wait(rlist, timeout=None) function for polling multiple
objects at once. On Unix this is just a wrapper for
select(rlist, [], [], timeout=None).
* Removes use of the SentinelReady exception and the sentinels argument
to certain methods. concurrent.futures.process has been changed to
use wait() instead of SentinelReady.
* Fixes bugs concerning PipeConnection.poll() and messages of zero
length.
* Fixes PipeListener.accept() to call ConnectNamedPipe() with
overlapped=True.
* Fixes Queue.empty() and SimpleQueue.empty() so that they are
threadsafe on Windows.
* Now PipeConnection.poll() and wait() will not modify the pipe except
possibly by consuming a zero length message. (Previously poll()
could consume a partial message.)
* All of multiprocesing's pipe related blocking functions/methods are
now interruptible by SIGINT on Windows.
This makes the C implementation more aligned with the Python implementation.
Also added some tests to ensure that Element is now a type and that it can
be subclassed.
and lifetime issues of dynamically allocated Py_buffer members (#9990)
as well as crashes (#8305, #7433). Many new features have been added
(See whatsnew/3.3), and the documentation has been updated extensively.
The ndarray test object from _testbuffer.c implements all aspects of
PEP-3118, so further development towards the complete implementation
of the PEP can proceed in a test-driven manner.
Thanks to Nick Coghlan, Antoine Pitrou and Pauli Virtanen for review
and many ideas.
- Issue #12834: Fix incorrect results of memoryview.tobytes() for
non-contiguous arrays.
- Issue #5231: Introduce memoryview.cast() method that allows changing
format and shape without making a copy of the underlying memory.
in order to make algorithmic complexity attacks on (e.g.) web apps much more complicated.
The environment variable PYTHONHASHSEED and the new command line flag -R control this
behavior.
in order to make algorithmic complexity attacks on (e.g.) web apps much more complicated.
The environment variable PYTHONHASHSEED and the new command line flag -R control this
behavior.
Alexander Belopolsky
Eli Bendersky
Martin v. Löwis
Victor Stinner
Stefan Krah
Richard Oudkerk
Gregory P. Smith
Kristjan Valur Jonsson
Antoine Pitrou
Meador Inge
Vinay Sajip
Benjamin Peterson
Hynek Schlawack
Eric V. Smith
Brian Curtin
Ross Lagerwall
Mark Dickinson
Nadeem Vawda
Larry Hastings
Brett Cannon
Jesus Cea
Kristján Valur Jónsson
Andrew Svetlov
R David Murray
Charles-François Natali
Victor Stinner
Sean Reifschneider
Łukasz Langa
Florent Xicluna
Éric Araujo
Georg Brandl
Petri Lehtinen