When Python is not compiled with PGO, the performance of Python on call_simple
and call_method microbenchmarks depend highly on the code placement. In the
worst case, the performance slowdown can be up to 70%.
The GCC __attribute__((hot)) attribute helps to keep hot code close to reduce
the risk of such major slowdown. This attribute is ignored when Python is
compiled with PGO.
The following functions are considered as hot according to statistics collected
by perf record/perf report:
* _PyEval_EvalFrameDefault()
* call_function()
* _PyFunction_FastCall()
* PyFrame_New()
* frame_dealloc()
* PyErr_Occurred()
Issue #26107: The format of the co_lnotab attribute of code objects changes to
support negative line number delta.
Changes:
* assemble_lnotab(): if line number delta is less than -128 or greater than
127, emit multiple (offset_delta, lineno_delta) in co_lnotab
* update functions decoding co_lnotab to use signed 8-bit integers
- dis.findlinestarts()
- PyCode_Addr2Line()
- _PyCode_CheckLineNumber()
- frame_setlineno()
* update lnotab_notes.txt
* increase importlib MAGIC_NUMBER to 3361
* document the change in What's New in Python 3.6
* cleanup also PyCode_Optimize() to use better variable names
crash when a generator is created in a C thread that is destroyed while the
generator is still used. The issue was that a generator contains a frame, and
the frame kept a reference to the Python state of the destroyed C thread. The
crash occurs when a trace function is setup.
It is now possible to use a custom type for the __builtins__ namespace, instead
of a dict. It can be used for sandboxing for example. Raise also a NameError
instead of ImportError if __build_class__ name if not found in __builtins__.
This allows generators that are using yield from to be seen by debuggers. It
also kills the f_yieldfrom field on frame objects.
Patch mostly from Mark Shannon with a few tweaks by me.
svn+ssh://pythondev@svn.python.org/python/trunk
........
r72487 | jeffrey.yasskin | 2009-05-08 17:51:06 -0400 (Fri, 08 May 2009) | 7 lines
PyCode_NewEmpty:
Most uses of PyCode_New found by http://www.google.com/codesearch?q=PyCode_New
are trying to build an empty code object, usually to put it in a dummy frame
object. This patch adds a PyCode_NewEmpty wrapper which lets the user specify
just the filename, function name, and first line number, instead of also
requiring lots of code internals.
........
r72488 | jeffrey.yasskin | 2009-05-08 18:23:21 -0400 (Fri, 08 May 2009) | 13 lines
Issue 5954, PyFrame_GetLineNumber:
Most uses of PyCode_Addr2Line
(http://www.google.com/codesearch?q=PyCode_Addr2Line) are just trying to get
the line number of a specified frame, but there's no way to do that directly.
Forcing people to go through the code object makes them know more about the
guts of the interpreter than they should need.
The remaining uses of PyCode_Addr2Line seem to be getting the line from a
traceback (for example,
http://www.google.com/codesearch/p?hl=en#u_9_nDrchrw/pygame-1.7.1release/src/base.c&q=PyCode_Addr2Line),
which is replaced by the tb_lineno field. So we may be able to deprecate
PyCode_Addr2Line entirely for external use.
........
r72879 | jeffrey.yasskin | 2009-05-23 19:23:01 -0400 (Sat, 23 May 2009) | 14 lines
Issue #6042:
lnotab-based tracing is very complicated and isn't documented very well. There
were at least 3 comment blocks purporting to document co_lnotab, and none did a
very good job. This patch unifies them into Objects/lnotab_notes.txt which
tries to completely capture the current state of affairs.
I also discovered that we've attached 2 layers of patches to the basic tracing
scheme. The first layer avoids jumping to instructions that don't start a line,
to avoid problems in if statements and while loops. The second layer
discovered that jumps backward do need to trace at instructions that don't
start a line, so it added extra lnotab entries for 'while' and 'for' loops, and
added a special case for backward jumps within the same line. I replaced these
patches by just treating forward and backward jumps differently.
........
svn+ssh://pythondev@svn.python.org/python/trunk
........
r73114 | amaury.forgeotdarc | 2009-06-01 22:53:18 +0200 (lun., 01 juin 2009) | 3 lines
#4547: When debugging a very large function, it was not always
possible to update the lineno attribute of the current frame.
........
svn+ssh://pythondev@svn.python.org/python/trunk
........
r73114 | amaury.forgeotdarc | 2009-06-01 22:53:18 +0200 (lun., 01 juin 2009) | 3 lines
#4547: When debugging a very large function, it was not always
possible to update the lineno attribute of the current frame.
........
svn+ssh://pythondev@svn.python.org/python/trunk
........
r72776 | jeffrey.yasskin | 2009-05-18 14:14:54 -0700 (Mon, 18 May 2009) | 6 lines
While I was modifying test_trace, it threw an exception when I accidentally
made it try to set the line number from the trace callback for a 'call' event.
This patch makes the error message a little more helpful in that case, and
makes it a little less likely that a future editor will make the same mistake
in test_trace.
........
r72796 | jeffrey.yasskin | 2009-05-20 10:57:57 -0700 (Wed, 20 May 2009) | 3 lines
Fix issue #1689458 by teaching frame_setlineno how to jump to the first line of
a code object.
........
made it try to set the line number from the trace callback for a 'call' event.
This patch makes the error message a little more helpful in that case, and
makes it a little less likely that a future editor will make the same mistake
in test_trace.
Most uses of PyCode_Addr2Line
(http://www.google.com/codesearch?q=PyCode_Addr2Line) are just trying to get
the line number of a specified frame, but there's no way to do that directly.
Forcing people to go through the code object makes them know more about the
guts of the interpreter than they should need.
The remaining uses of PyCode_Addr2Line seem to be getting the line from a
traceback (for example,
http://www.google.com/codesearch/p?hl=en#u_9_nDrchrw/pygame-1.7.1release/src/base.c&q=PyCode_Addr2Line),
which is replaced by the tb_lineno field. So we may be able to deprecate
PyCode_Addr2Line entirely for external use.
svn+ssh://pythondev@svn.python.org/python/trunk
........
r71722 | benjamin.peterson | 2009-04-18 15:12:47 -0500 (Sat, 18 Apr 2009) | 1 line
try to initalize all builtin types with PyType_Ready to avoid problems like #5787
........
INADA Naoki
Victor Stinner
Serhiy Storchaka
Yury Selivanov
Antoine Pitrou
David Malcolm
Kristjan Valur Jonsson
Benjamin Peterson
Nick Coghlan
Mark Dickinson
Alexandre Vassalotti
Amaury Forgeot d'Arc
Jeffrey Yasskin