cpython-lru_cache-weakref: Doc/libprofile.tex annotate

annotate Doc/libprofile.tex @ 5817:48b94de85bf3 legacy-trunk

Extensive changes by AMK.

author	Guido van Rossum <guido@python.org>
date	Thu, 17 Jul 1997 16:29:42 +0000
parents	d88cb4d26f13
children	3468ea8645ca

rev	line source
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	1 \chapter{The Python Profiler}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	2 \stmodindex{profile}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	3 \stmodindex{pstats}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	4
4728 b218f294b726 (lib<all sorts of stuff>.tex): Fred Drake <fdrake@acm.org> parents: 3377 diff changeset	5 Copyright \copyright{} 1994, by InfoSeek Corporation, all rights reserved.
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	6
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	7 Written by James Roskind%
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	8 \footnote{
2491 fb8e08ec88dd changes (suggested) by Soren Larsen Guido van Rossum <guido@python.org> parents: 2465 diff changeset	9 Updated and converted to \LaTeX\ by Guido van Rossum. The references to
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	10 the old profiler are left in the text, although it no longer exists.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	11 }
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	12
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	13 Permission to use, copy, modify, and distribute this Python software
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	14 and its associated documentation for any purpose (subject to the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	15 restriction in the following sentence) without fee is hereby granted,
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	16 provided that the above copyright notice appears in all copies, and
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	17 that both that copyright notice and this permission notice appear in
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	18 supporting documentation, and that the name of InfoSeek not be used in
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	19 advertising or publicity pertaining to distribution of the software
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	20 without specific, written prior permission. This permission is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	21 explicitly restricted to the copying and modification of the software
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	22 to remain in Python, compiled Python, or other languages (such as C)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	23 wherein the modified or derived code is exclusively imported into a
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	24 Python module.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	25
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	26 INFOSEEK CORPORATION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	27 SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	28 FITNESS. IN NO EVENT SHALL INFOSEEK CORPORATION BE LIABLE FOR ANY
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	29 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	30 RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	31 CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	32 CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	33
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	34
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	35 The profiler was written after only programming in Python for 3 weeks.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	36 As a result, it is probably clumsy code, but I don't know for sure yet
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	37 'cause I'm a beginner :-). I did work hard to make the code run fast,
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	38 so that profiling would be a reasonable thing to do. I tried not to
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	39 repeat code fragments, but I'm sure I did some stuff in really awkward
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	40 ways at times. Please send suggestions for improvements to:
3377 827338699094 change jars email Guido van Rossum <guido@python.org> parents: 2647 diff changeset	41 \code{jar@netscape.com}. I won't promise \emph{any} support. ...but
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	42 I'd appreciate the feedback.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	43
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	44
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	45 \section{Introduction to the profiler}
2581 4d28b655b728 added nodename macro calls for new very long section names Guido van Rossum <guido@python.org> parents: 2576 diff changeset	46 \nodename{Profiler Introduction}
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	47
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	48 A \dfn{profiler} is a program that describes the run time performance
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	49 of a program, providing a variety of statistics. This documentation
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	50 describes the profiler functionality provided in the modules
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	51 \code{profile} and \code{pstats.} This profiler provides
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	52 \dfn{deterministic profiling} of any Python programs. It also
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	53 provides a series of report generation tools to allow users to rapidly
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	54 examine the results of a profile operation.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	55
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	56
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	57 \section{How Is This Profiler Different From The Old Profiler?}
2581 4d28b655b728 added nodename macro calls for new very long section names Guido van Rossum <guido@python.org> parents: 2576 diff changeset	58 \nodename{Profiler Changes}
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	59
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	60 The big changes from old profiling module are that you get more
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	61 information, and you pay less CPU time. It's not a trade-off, it's a
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	62 trade-up.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	63
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	64 To be specific:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	65
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	66 \begin{description}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	67
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	68 \item[Bugs removed:]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	69 Local stack frame is no longer molested, execution time is now charged
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	70 to correct functions.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	71
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	72 \item[Accuracy increased:]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	73 Profiler execution time is no longer charged to user's code,
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	74 calibration for platform is supported, file reads are not done \emph{by}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	75 profiler \emph{during} profiling (and charged to user's code!).
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	76
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	77 \item[Speed increased:]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	78 Overhead CPU cost was reduced by more than a factor of two (perhaps a
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	79 factor of five), lightweight profiler module is all that must be
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	80 loaded, and the report generating module (\code{pstats}) is not needed
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	81 during profiling.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	82
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	83 \item[Recursive functions support:]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	84 Cumulative times in recursive functions are correctly calculated;
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	85 recursive entries are counted.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	86
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	87 \item[Large growth in report generating UI:]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	88 Distinct profiles runs can be added together forming a comprehensive
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	89 report; functions that import statistics take arbitrary lists of
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	90 files; sorting criteria is now based on keywords (instead of 4 integer
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	91 options); reports shows what functions were profiled as well as what
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	92 profile file was referenced; output format has been improved.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	93
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	94 \end{description}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	95
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	96
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	97 \section{Instant Users Manual}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	98
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	99 This section is provided for users that ``don't want to read the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	100 manual.'' It provides a very brief overview, and allows a user to
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	101 rapidly perform profiling on an existing application.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	102
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	103 To profile an application with a main entry point of \samp{foo()}, you
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	104 would add the following to your module:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	105
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	106 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	107 import profile
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	108 profile.run("foo()")
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	109 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	110
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	111 The above action would cause \samp{foo()} to be run, and a series of
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	112 informative lines (the profile) to be printed. The above approach is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	113 most useful when working with the interpreter. If you would like to
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	114 save the results of a profile into a file for later examination, you
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	115 can supply a file name as the second argument to the \code{run()}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	116 function:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	117
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	118 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	119 import profile
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	120 profile.run("foo()", 'fooprof')
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	121 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	122
5681 d88cb4d26f13 Mention use of profile.py to run a script (AMK). Guido van Rossum <guido@python.org> parents: 4728 diff changeset	123 \code{profile.py} can also be invoked as
d88cb4d26f13 Mention use of profile.py to run a script (AMK). Guido van Rossum <guido@python.org> parents: 4728 diff changeset	124 a script to profile another script. For example:
d88cb4d26f13 Mention use of profile.py to run a script (AMK). Guido van Rossum <guido@python.org> parents: 4728 diff changeset	125 \code{python /usr/local/lib/python1.4/profile.py myscript.py}
d88cb4d26f13 Mention use of profile.py to run a script (AMK). Guido van Rossum <guido@python.org> parents: 4728 diff changeset	126
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	127 When you wish to review the profile, you should use the methods in the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	128 \code{pstats} module. Typically you would load the statistics data as
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	129 follows:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	130
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	131 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	132 import pstats
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	133 p = pstats.Stats('fooprof')
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	134 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	135
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	136 The class \code{Stats} (the above code just created an instance of
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	137 this class) has a variety of methods for manipulating and printing the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	138 data that was just read into \samp{p}. When you ran
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	139 \code{profile.run()} above, what was printed was the result of three
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	140 method calls:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	141
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	142 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	143 p.strip_dirs().sort_stats(-1).print_stats()
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	144 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	145
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	146 The first method removed the extraneous path from all the module
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	147 names. The second method sorted all the entries according to the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	148 standard module/line/name string that is printed (this is to comply
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	149 with the semantics of the old profiler). The third method printed out
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	150 all the statistics. You might try the following sort calls:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	151
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	152 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	153 p.sort_stats('name')
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	154 p.print_stats()
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	155 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	156
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	157 The first call will actually sort the list by function name, and the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	158 second call will print out the statistics. The following are some
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	159 interesting calls to experiment with:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	160
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	161 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	162 p.sort_stats('cumulative').print_stats(10)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	163 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	164
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	165 This sorts the profile by cumulative time in a function, and then only
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	166 prints the ten most significant lines. If you want to understand what
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	167 algorithms are taking time, the above line is what you would use.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	168
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	169 If you were looking to see what functions were looping a lot, and
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	170 taking a lot of time, you would do:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	171
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	172 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	173 p.sort_stats('time').print_stats(10)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	174 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	175
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	176 to sort according to time spent within each function, and then print
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	177 the statistics for the top ten functions.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	178
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	179 You might also try:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	180
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	181 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	182 p.sort_stats('file').print_stats('__init__')
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	183 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	184
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	185 This will sort all the statistics by file name, and then print out
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	186 statistics for only the class init methods ('cause they are spelled
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	187 with \code{__init__} in them). As one final example, you could try:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	188
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	189 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	190 p.sort_stats('time', 'cum').print_stats(.5, 'init')
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	191 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	192
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	193 This line sorts statistics with a primary key of time, and a secondary
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	194 key of cumulative time, and then prints out some of the statistics.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	195 To be specific, the list is first culled down to 50\% (re: \samp{.5})
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	196 of its original size, then only lines containing \code{init} are
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	197 maintained, and that sub-sub-list is printed.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	198
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	199 If you wondered what functions called the above functions, you could
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	200 now (\samp{p} is still sorted according to the last criteria) do:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	201
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	202 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	203 p.print_callers(.5, 'init')
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	204 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	205
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	206 and you would get a list of callers for each of the listed functions.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	207
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	208 If you want more functionality, you're going to have to read the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	209 manual, or guess what the following functions do:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	210
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	211 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	212 p.print_callees()
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	213 p.add('fooprof')
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	214 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	215
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	216
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	217 \section{What Is Deterministic Profiling?}
2581 4d28b655b728 added nodename macro calls for new very long section names Guido van Rossum <guido@python.org> parents: 2576 diff changeset	218 \nodename{Deterministic Profiling}
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	219
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	220 \dfn{Deterministic profiling} is meant to reflect the fact that all
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	221 \dfn{function call}, \dfn{function return}, and \dfn{exception} events
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	222 are monitored, and precise timings are made for the intervals between
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	223 these events (during which time the user's code is executing). In
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	224 contrast, \dfn{statistical profiling} (which is not done by this
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	225 module) randomly samples the effective instruction pointer, and
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	226 deduces where time is being spent. The latter technique traditionally
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	227 involves less overhead (as the code does not need to be instrumented),
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	228 but provides only relative indications of where time is being spent.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	229
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	230 In Python, since there is an interpreter active during execution, the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	231 presence of instrumented code is not required to do deterministic
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	232 profiling. Python automatically provides a \dfn{hook} (optional
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	233 callback) for each event. In addition, the interpreted nature of
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	234 Python tends to add so much overhead to execution, that deterministic
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	235 profiling tends to only add small processing overhead in typical
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	236 applications. The result is that deterministic profiling is not that
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	237 expensive, yet provides extensive run time statistics about the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	238 execution of a Python program.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	239
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	240 Call count statistics can be used to identify bugs in code (surprising
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	241 counts), and to identify possible inline-expansion points (high call
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	242 counts). Internal time statistics can be used to identify ``hot
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	243 loops'' that should be carefully optimized. Cumulative time
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	244 statistics should be used to identify high level errors in the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	245 selection of algorithms. Note that the unusual handling of cumulative
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	246 times in this profiler allows statistics for recursive implementations
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	247 of algorithms to be directly compared to iterative implementations.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	248
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	249
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	250 \section{Reference Manual}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	251
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	252 \renewcommand{\indexsubitem}{(profiler function)}
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	253
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	254 The primary entry point for the profiler is the global function
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	255 \code{profile.run()}. It is typically used to create any profile
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	256 information. The reports are formatted and printed using methods of
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	257 the class \code{pstats.Stats}. The following is a description of all
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	258 of these standard entry points and functions. For a more in-depth
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	259 view of some of the code, consider reading the later section on
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	260 Profiler Extensions, which includes discussion of how to derive
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	261 ``better'' profilers from the classes presented, or reading the source
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	262 code for these modules.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	263
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	264 \begin{funcdesc}{profile.run}{string\optional{\, filename\optional{\, ...}}}
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	265
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	266 This function takes a single argument that has can be passed to the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	267 \code{exec} statement, and an optional file name. In all cases this
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	268 routine attempts to \code{exec} its first argument, and gather profiling
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	269 statistics from the execution. If no file name is present, then this
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	270 function automatically prints a simple profiling report, sorted by the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	271 standard name string (file/line/function-name) that is presented in
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	272 each line. The following is a typical output from such a call:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	273
2647 9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	274 \small{
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	275 \begin{verbatim}
2647 9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	276 main()
9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	277 2706 function calls (2004 primitive calls) in 4.504 CPU seconds
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	278
2647 9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	279 Ordered by: standard name
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	280
2647 9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	281 ncalls tottime percall cumtime percall filename:lineno(function)
9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	282 2 0.006 0.003 0.953 0.477 pobject.py:75(save_objects)
9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	283 43/3 0.533 0.012 0.749 0.250 pobject.py:99(evaluate)
9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	284 ...
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	285 \end{verbatim}
2647 9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	286 }
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	287
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	288 The first line indicates that this profile was generated by the call:\\
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	289 \code{profile.run('main()')}, and hence the exec'ed string is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	290 \code{'main()'}. The second line indicates that 2706 calls were
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	291 monitored. Of those calls, 2004 were \dfn{primitive}. We define
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	292 \dfn{primitive} to mean that the call was not induced via recursion.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	293 The next line: \code{Ordered by:\ standard name}, indicates that
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	294 the text string in the far right column was used to sort the output.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	295 The column headings include:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	296
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	297 \begin{description}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	298
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	299 \item[ncalls ]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	300 for the number of calls,
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	301
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	302 \item[tottime ]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	303 for the total time spent in the given function (and excluding time
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	304 made in calls to sub-functions),
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	305
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	306 \item[percall ]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	307 is the quotient of \code{tottime} divided by \code{ncalls}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	308
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	309 \item[cumtime ]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	310 is the total time spent in this and all subfunctions (i.e., from
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	311 invocation till exit). This figure is accurate \emph{even} for recursive
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	312 functions.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	313
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	314 \item[percall ]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	315 is the quotient of \code{cumtime} divided by primitive calls
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	316
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	317 \item[filename:lineno(function) ]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	318 provides the respective data of each function
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	319
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	320 \end{description}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	321
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	322 When there are two numbers in the first column (e.g.: \samp{43/3}),
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	323 then the latter is the number of primitive calls, and the former is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	324 the actual number of calls. Note that when the function does not
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	325 recurse, these two values are the same, and only the single figure is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	326 printed.
2647 9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	327
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	328 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	329
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	330 \begin{funcdesc}{pstats.Stats}{filename\optional{\, ...}}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	331 This class constructor creates an instance of a ``statistics object''
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	332 from a \var{filename} (or set of filenames). \code{Stats} objects are
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	333 manipulated by methods, in order to print useful reports.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	334
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	335 The file selected by the above constructor must have been created by
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	336 the corresponding version of \code{profile}. To be specific, there is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	337 \emph{NO} file compatibility guaranteed with future versions of this
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	338 profiler, and there is no compatibility with files produced by other
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	339 profilers (e.g., the old system profiler).
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	340
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	341 If several files are provided, all the statistics for identical
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	342 functions will be coalesced, so that an overall view of several
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	343 processes can be considered in a single report. If additional files
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	344 need to be combined with data in an existing \code{Stats} object, the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	345 \code{add()} method can be used.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	346 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	347
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	348
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	349 \subsection{The \sectcode{Stats} Class}
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	350
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	351 \renewcommand{\indexsubitem}{(Stats method)}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	352
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	353 \begin{funcdesc}{strip_dirs}{}
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	354 This method for the \code{Stats} class removes all leading path information
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	355 from file names. It is very useful in reducing the size of the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	356 printout to fit within (close to) 80 columns. This method modifies
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	357 the object, and the stripped information is lost. After performing a
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	358 strip operation, the object is considered to have its entries in a
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	359 ``random'' order, as it was just after object initialization and
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	360 loading. If \code{strip_dirs()} causes two function names to be
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	361 indistinguishable (i.e., they are on the same line of the same
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	362 filename, and have the same function name), then the statistics for
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	363 these two entries are accumulated into a single entry.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	364 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	365
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	366
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	367 \begin{funcdesc}{add}{filename\optional{\, ...}}
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	368 This method of the \code{Stats} class accumulates additional profiling
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	369 information into the current profiling object. Its arguments should
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	370 refer to filenames created by the corresponding version of
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	371 \code{profile.run()}. Statistics for identically named (re: file,
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	372 line, name) functions are automatically accumulated into single
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	373 function statistics.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	374 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	375
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	376 \begin{funcdesc}{sort_stats}{key\optional{\, ...}}
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	377 This method modifies the \code{Stats} object by sorting it according to the
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	378 supplied criteria. The argument is typically a string identifying the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	379 basis of a sort (example: \code{"time"} or \code{"name"}).
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	380
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	381 When more than one key is provided, then additional keys are used as
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	382 secondary criteria when the there is equality in all keys selected
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	383 before them. For example, sort_stats('name', 'file') will sort all
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	384 the entries according to their function name, and resolve all ties
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	385 (identical function names) by sorting by file name.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	386
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	387 Abbreviations can be used for any key names, as long as the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	388 abbreviation is unambiguous. The following are the keys currently
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	389 defined:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	390
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	391 \begin{tableii}{\|l\|l\|}{code}{Valid Arg}{Meaning}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	392 \lineii{"calls"}{call count}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	393 \lineii{"cumulative"}{cumulative time}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	394 \lineii{"file"}{file name}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	395 \lineii{"module"}{file name}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	396 \lineii{"pcalls"}{primitive call count}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	397 \lineii{"line"}{line number}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	398 \lineii{"name"}{function name}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	399 \lineii{"nfl"}{name/file/line}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	400 \lineii{"stdname"}{standard name}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	401 \lineii{"time"}{internal time}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	402 \end{tableii}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	403
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	404 Note that all sorts on statistics are in descending order (placing
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	405 most time consuming items first), where as name, file, and line number
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	406 searches are in ascending order (i.e., alphabetical). The subtle
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	407 distinction between \code{"nfl"} and \code{"stdname"} is that the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	408 standard name is a sort of the name as printed, which means that the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	409 embedded line numbers get compared in an odd way. For example, lines
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	410 3, 20, and 40 would (if the file names were the same) appear in the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	411 string order 20, 3 and 40. In contrast, \code{"nfl"} does a numeric
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	412 compare of the line numbers. In fact, \code{sort_stats("nfl")} is the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	413 same as \code{sort_stats("name", "file", "line")}.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	414
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	415 For compatibility with the old profiler, the numeric arguments
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	416 \samp{-1}, \samp{0}, \samp{1}, and \samp{2} are permitted. They are
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	417 interpreted as \code{"stdname"}, \code{"calls"}, \code{"time"}, and
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	418 \code{"cumulative"} respectively. If this old style format (numeric)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	419 is used, only one sort key (the numeric key) will be used, and
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	420 additional arguments will be silently ignored.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	421 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	422
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	423
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	424 \begin{funcdesc}{reverse_order}{}
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	425 This method for the \code{Stats} class reverses the ordering of the basic
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	426 list within the object. This method is provided primarily for
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	427 compatibility with the old profiler. Its utility is questionable
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	428 now that ascending vs descending order is properly selected based on
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	429 the sort key of choice.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	430 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	431
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	432 \begin{funcdesc}{print_stats}{restriction\optional{\, ...}}
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	433 This method for the \code{Stats} class prints out a report as described
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	434 in the \code{profile.run()} definition.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	435
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	436 The order of the printing is based on the last \code{sort_stats()}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	437 operation done on the object (subject to caveats in \code{add()} and
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	438 \code{strip_dirs())}.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	439
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	440 The arguments provided (if any) can be used to limit the list down to
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	441 the significant entries. Initially, the list is taken to be the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	442 complete set of profiled functions. Each restriction is either an
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	443 integer (to select a count of lines), or a decimal fraction between
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	444 0.0 and 1.0 inclusive (to select a percentage of lines), or a regular
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	445 expression (to pattern match the standard name that is printed). If
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	446 several restrictions are provided, then they are applied sequentially.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	447 For example:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	448
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	449 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	450 print_stats(.1, "foo:")
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	451 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	452
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	453 would first limit the printing to first 10\% of list, and then only
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	454 print functions that were part of filename \samp{.*foo:}. In
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	455 contrast, the command:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	456
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	457 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	458 print_stats("foo:", .1)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	459 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	460
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	461 would limit the list to all functions having file names \samp{.*foo:},
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	462 and then proceed to only print the first 10\% of them.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	463 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	464
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	465
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	466 \begin{funcdesc}{print_callers}{restrictions\optional{\, ...}}
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	467 This method for the \code{Stats} class prints a list of all functions
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	468 that called each function in the profiled database. The ordering is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	469 identical to that provided by \code{print_stats()}, and the definition
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	470 of the restricting argument is also identical. For convenience, a
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	471 number is shown in parentheses after each caller to show how many
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	472 times this specific call was made. A second non-parenthesized number
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	473 is the cumulative time spent in the function at the right.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	474 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	475
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	476 \begin{funcdesc}{print_callees}{restrictions\optional{\, ...}}
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	477 This method for the \code{Stats} class prints a list of all function
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	478 that were called by the indicated function. Aside from this reversal
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	479 of direction of calls (re: called vs was called by), the arguments and
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	480 ordering are identical to the \code{print_callers()} method.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	481 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	482
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	483 \begin{funcdesc}{ignore}{}
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	484 This method of the \code{Stats} class is used to dispose of the value
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	485 returned by earlier methods. All standard methods in this class
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	486 return the instance that is being processed, so that the commands can
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	487 be strung together. For example:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	488
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	489 \begin{verbatim}
2647 9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	490 pstats.Stats('foofile').strip_dirs().sort_stats('cum') \
9b7e6d9a528d typos, layout and other small things Guido van Rossum <guido@python.org> parents: 2596 diff changeset	491 .print_stats().ignore()
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	492 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	493
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	494 would perform all the indicated functions, but it would not return
2576 f47bc5554418 mass changes; fix titles; add examples; correct typos; clarifications; Guido van Rossum <guido@python.org> parents: 2491 diff changeset	495 the final reference to the \code{Stats} instance.%
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	496 \footnote{
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	497 This was once necessary, when Python would print any unused expression
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	498 result that was not \code{None}. The method is still defined for
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	499 backward compatibility.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	500 }
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	501 \end{funcdesc}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	502
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	503
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	504 \section{Limitations}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	505
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	506 There are two fundamental limitations on this profiler. The first is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	507 that it relies on the Python interpreter to dispatch \dfn{call},
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	508 \dfn{return}, and \dfn{exception} events. Compiled C code does not
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	509 get interpreted, and hence is ``invisible'' to the profiler. All time
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	510 spent in C code (including builtin functions) will be charged to the
2596 31777622ae93 some new material Guido van Rossum <guido@python.org> parents: 2581 diff changeset	511 Python function that invoked the C code. If the C code calls out
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	512 to some native Python code, then those calls will be profiled
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	513 properly.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	514
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	515 The second limitation has to do with accuracy of timing information.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	516 There is a fundamental problem with deterministic profilers involving
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	517 accuracy. The most obvious restriction is that the underlying ``clock''
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	518 is only ticking at a rate (typically) of about .001 seconds. Hence no
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	519 measurements will be more accurate that that underlying clock. If
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	520 enough measurements are taken, then the ``error'' will tend to average
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	521 out. Unfortunately, removing this first error induces a second source
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	522 of error...
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	523
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	524 The second problem is that it ``takes a while'' from when an event is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	525 dispatched until the profiler's call to get the time actually
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	526 \emph{gets} the state of the clock. Similarly, there is a certain lag
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	527 when exiting the profiler event handler from the time that the clock's
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	528 value was obtained (and then squirreled away), until the user's code
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	529 is once again executing. As a result, functions that are called many
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	530 times, or call many functions, will typically accumulate this error.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	531 The error that accumulates in this fashion is typically less than the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	532 accuracy of the clock (i.e., less than one clock tick), but it
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	533 \emph{can} accumulate and become very significant. This profiler
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	534 provides a means of calibrating itself for a given platform so that
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	535 this error can be probabilistically (i.e., on the average) removed.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	536 After the profiler is calibrated, it will be more accurate (in a least
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	537 square sense), but it will sometimes produce negative numbers (when
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	538 call counts are exceptionally low, and the gods of probability work
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	539 against you :-). ) Do \emph{NOT} be alarmed by negative numbers in
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	540 the profile. They should \emph{only} appear if you have calibrated
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	541 your profiler, and the results are actually better than without
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	542 calibration.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	543
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	544
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	545 \section{Calibration}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	546
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	547 The profiler class has a hard coded constant that is added to each
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	548 event handling time to compensate for the overhead of calling the time
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	549 function, and socking away the results. The following procedure can
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	550 be used to obtain this constant for a given platform (see discussion
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	551 in section Limitations above).
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	552
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	553 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	554 import profile
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	555 pr = profile.Profile()
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	556 pr.calibrate(100)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	557 pr.calibrate(100)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	558 pr.calibrate(100)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	559 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	560
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	561 The argument to calibrate() is the number of times to try to do the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	562 sample calls to get the CPU times. If your computer is \emph{very}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	563 fast, you might have to do:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	564
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	565 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	566 pr.calibrate(1000)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	567 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	568
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	569 or even:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	570
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	571 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	572 pr.calibrate(10000)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	573 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	574
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	575 The object of this exercise is to get a fairly consistent result.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	576 When you have a consistent answer, you are ready to use that number in
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	577 the source code. For a Sun Sparcstation 1000 running Solaris 2.3, the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	578 magical number is about .00053. If you have a choice, you are better
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	579 off with a smaller constant, and your results will ``less often'' show
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	580 up as negative in profile statistics.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	581
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	582 The following shows how the trace_dispatch() method in the Profile
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	583 class should be modified to install the calibration constant on a Sun
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	584 Sparcstation 1000:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	585
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	586 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	587 def trace_dispatch(self, frame, event, arg):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	588 t = self.timer()
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	589 t = t[0] + t[1] - self.t - .00053 # Calibration constant
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	590
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	591 if self.dispatch[event](frame,t):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	592 t = self.timer()
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	593 self.t = t[0] + t[1]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	594 else:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	595 r = self.timer()
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	596 self.t = r[0] + r[1] - t # put back unrecorded delta
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	597 return
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	598 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	599
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	600 Note that if there is no calibration constant, then the line
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	601 containing the callibration constant should simply say:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	602
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	603 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	604 t = t[0] + t[1] - self.t # no calibration constant
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	605 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	606
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	607 You can also achieve the same results using a derived class (and the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	608 profiler will actually run equally fast!!), but the above method is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	609 the simplest to use. I could have made the profiler ``self
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	610 calibrating'', but it would have made the initialization of the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	611 profiler class slower, and would have required some \emph{very} fancy
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	612 coding, or else the use of a variable where the constant \samp{.00053}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	613 was placed in the code shown. This is a \strong{VERY} critical
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	614 performance section, and there is no reason to use a variable lookup
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	615 at this point, when a constant can be used.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	616
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	617
2581 4d28b655b728 added nodename macro calls for new very long section names Guido van Rossum <guido@python.org> parents: 2576 diff changeset	618 \section{Extensions --- Deriving Better Profilers}
4d28b655b728 added nodename macro calls for new very long section names Guido van Rossum <guido@python.org> parents: 2576 diff changeset	619 \nodename{Profiler Extensions}
2465 1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	620
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	621 The \code{Profile} class of module \code{profile} was written so that
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	622 derived classes could be developed to extend the profiler. Rather
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	623 than describing all the details of such an effort, I'll just present
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	624 the following two examples of derived classes that can be used to do
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	625 profiling. If the reader is an avid Python programmer, then it should
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	626 be possible to use these as a model and create similar (and perchance
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	627 better) profile classes.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	628
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	629 If all you want to do is change how the timer is called, or which
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	630 timer function is used, then the basic class has an option for that in
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	631 the constructor for the class. Consider passing the name of a
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	632 function to call into the constructor:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	633
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	634 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	635 pr = profile.Profile(your_time_func)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	636 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	637
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	638 The resulting profiler will call \code{your_time_func()} instead of
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	639 \code{os.times()}. The function should return either a single number
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	640 or a list of numbers (like what \code{os.times()} returns). If the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	641 function returns a single time number, or the list of returned numbers
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	642 has length 2, then you will get an especially fast version of the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	643 dispatch routine.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	644
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	645 Be warned that you \emph{should} calibrate the profiler class for the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	646 timer function that you choose. For most machines, a timer that
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	647 returns a lone integer value will provide the best results in terms of
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	648 low overhead during profiling. (os.times is \emph{pretty} bad, 'cause
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	649 it returns a tuple of floating point values, so all arithmetic is
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	650 floating point in the profiler!). If you want to substitute a
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	651 better timer in the cleanest fashion, you should derive a class, and
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	652 simply put in the replacement dispatch method that better handles your
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	653 timer call, along with the appropriate calibration constant :-).
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	654
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	655
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	656 \subsection{OldProfile Class}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	657
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	658 The following derived profiler simulates the old style profiler,
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	659 providing errant results on recursive functions. The reason for the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	660 usefulness of this profiler is that it runs faster (i.e., less
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	661 overhead) than the old profiler. It still creates all the caller
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	662 stats, and is quite useful when there is \emph{no} recursion in the
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	663 user's code. It is also a lot more accurate than the old profiler, as
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	664 it does not charge all its overhead time to the user's code.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	665
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	666 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	667 class OldProfile(Profile):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	668
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	669 def trace_dispatch_exception(self, frame, t):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	670 rt, rtt, rct, rfn, rframe, rcur = self.cur
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	671 if rcur and not rframe is frame:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	672 return self.trace_dispatch_return(rframe, t)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	673 return 0
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	674
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	675 def trace_dispatch_call(self, frame, t):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	676 fn = `frame.f_code`
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	677
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	678 self.cur = (t, 0, 0, fn, frame, self.cur)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	679 if self.timings.has_key(fn):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	680 tt, ct, callers = self.timings[fn]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	681 self.timings[fn] = tt, ct, callers
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	682 else:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	683 self.timings[fn] = 0, 0, {}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	684 return 1
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	685
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	686 def trace_dispatch_return(self, frame, t):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	687 rt, rtt, rct, rfn, frame, rcur = self.cur
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	688 rtt = rtt + t
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	689 sft = rtt + rct
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	690
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	691 pt, ptt, pct, pfn, pframe, pcur = rcur
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	692 self.cur = pt, ptt+rt, pct+sft, pfn, pframe, pcur
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	693
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	694 tt, ct, callers = self.timings[rfn]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	695 if callers.has_key(pfn):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	696 callers[pfn] = callers[pfn] + 1
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	697 else:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	698 callers[pfn] = 1
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	699 self.timings[rfn] = tt+rtt, ct + sft, callers
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	700
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	701 return 1
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	702
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	703
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	704 def snapshot_stats(self):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	705 self.stats = {}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	706 for func in self.timings.keys():
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	707 tt, ct, callers = self.timings[func]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	708 nor_func = self.func_normalize(func)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	709 nor_callers = {}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	710 nc = 0
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	711 for func_caller in callers.keys():
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	712 nor_callers[self.func_normalize(func_caller)]=\
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	713 callers[func_caller]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	714 nc = nc + callers[func_caller]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	715 self.stats[nor_func] = nc, nc, tt, ct, nor_callers
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	716 \end{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	717
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	718
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	719 \subsection{HotProfile Class}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	720
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	721 This profiler is the fastest derived profile example. It does not
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	722 calculate caller-callee relationships, and does not calculate
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	723 cumulative time under a function. It only calculates time spent in a
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	724 function, so it runs very quickly (re: very low overhead). In truth,
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	725 the basic profiler is so fast, that is probably not worth the savings
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	726 to give up the data, but this class still provides a nice example.
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	727
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	728 \begin{verbatim}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	729 class HotProfile(Profile):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	730
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	731 def trace_dispatch_exception(self, frame, t):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	732 rt, rtt, rfn, rframe, rcur = self.cur
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	733 if rcur and not rframe is frame:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	734 return self.trace_dispatch_return(rframe, t)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	735 return 0
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	736
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	737 def trace_dispatch_call(self, frame, t):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	738 self.cur = (t, 0, frame, self.cur)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	739 return 1
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	740
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	741 def trace_dispatch_return(self, frame, t):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	742 rt, rtt, frame, rcur = self.cur
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	743
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	744 rfn = `frame.f_code`
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	745
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	746 pt, ptt, pframe, pcur = rcur
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	747 self.cur = pt, ptt+rt, pframe, pcur
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	748
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	749 if self.timings.has_key(rfn):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	750 nc, tt = self.timings[rfn]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	751 self.timings[rfn] = nc + 1, rt + rtt + tt
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	752 else:
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	753 self.timings[rfn] = 1, rt + rtt
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	754
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	755 return 1
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	756
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	757
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	758 def snapshot_stats(self):
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	759 self.stats = {}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	760 for func in self.timings.keys():
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	761 nc, tt = self.timings[func]
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	762 nor_func = self.func_normalize(func)
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	763 self.stats[nor_func] = nc, nc, tt, 0, {}
1f4141aafe36 converted docs for Jim Roskind's profiler Guido van Rossum <guido@python.org> parents: diff changeset	764 \end{verbatim}

Mercurial > cpython-lru_cache-weakref

annotate Doc/libprofile.tex @ 5817:48b94de85bf3 legacy-trunk