1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
#lang scribble/manual
@;{ manual.scrbl -- Scribble documentation for ppamltracer-racket
Copyright (C) 2013, 2014 Galois, Inc.
This program is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.
To contact Galois, complete the Web form at <http://corp.galois.com/contact/>
or write to Galois, Inc., 421 Southwest 6th Avenue, Suite 300, Portland,
Oregon, 97204-1622. }
@(require (for-label racket/base
racket/sequence))
@(require (for-label ppamltracer))
@title{ppamltracer}
ppamltracer is a lightweight, portable tracing library designed for explicit instrumention of generated code.
If you're writing a compiler and need hard data on your optimizer's efficacy, ppamltracer is the library for you.
This Racket library provides a high-level API on top of the libppamltracer C API.
ppamltracer's usage can be summed up in a couple lines:
@racketblock[
(require ppamltracer)
(let/tracer [tracer "/tmp/my_report"]
(let/phase tracer [phase "phase 1"]
(with-phase-running phase
(do-stuff)))
(let/phase tracer [phase "phase 2"]
(with-phase-running phase
(do-other-stuff))
(with-phase-running phase
(do-yet-more-stuff))))
]
This creates a report with the total runtime of @racket[do-stuff] recorded as "phase 1" and the total runtime of @racket[do-other-stuff] and @racket[do-yet-more-stuff] combined as "phase 2".
@secref{getting-started} contains a more lengthy example.
ppamltracer writes trace logs in the @hyperlink["http://tu-dresden.de/zih/otf/"]{Open Trace Format}, a free and open standard developed by the Zentrum für Informationsdienste und Hochleistungsrechnen (Center for Information Services and High-Performance Computing) at the Technical University of Dresden.
We developed ppamltracer as part of DARPA's @hyperlink["http://darpa.mil/Our_Work/I2O/Programs/Probabilistic_Programming_for_Advanced_Machine_Learning_(PPAML).aspx"]{Probabilistic Programming for Advancing Machine Learning} (PPAML) project.
@section[#:tag "getting-started"]{Getting Started}
This basic example demonstrates using ppamltracer to trace two functions -- a factorial function and a Fibonacci number generator.
@#reader scribble/comment-reader (racketblock
;; simple.rkt -- basic ppamltracer example
;; This file is in the public domain.
(require racket/sequence)
(require ppamltracer)
(define (fact phase n)
;; Record that we're running inside the factorial phase.
(with-phase-running phase
;; Compute the factorial.
(if (= n 0)
1
(* n (fact phase (- n 1))))))
(define (fib phase n)
;; Record that we're running inside the Fibonacci phase.
(with-phase-running phase
;; Compute the nth Fibonacci number.
(case n
[(0 1) n]
[else (+ (fib phase (- n 1)) (fib phase (- n 2)))])))
;; Start ppamltracer.
(let/tracer [tracer "/tmp/simple_report"]
;; Register the factorial phase.
(let/phase tracer [phase "fact"]
;; Print factorials.
(printf "Factorials: ")
(sequence-for-each (lambda (n) (printf "~a " (fact phase n)))
(in-range 40))
(printf "\n"))
;; Register the Fibonacci phase.
(let/phase tracer [phase "fib"]
;; Print Fibonacci numbers.
(printf "Fibonacci numbers: ")
(sequence-for-each (lambda (n) (printf "~a " (fib phase n)))
(in-range 16))
(printf "\n")))
)
@section{API in Depth}
@defmodule[ppamltracer]
@subsection{Tracers}
ppamltracer is fundamentally a set of stateful operations; the @racket[tracer] data type holds the state ppamltracer needs to operate properly.
@defproc[(tracer? [obj any/c])
boolean?]{
Evaluates to @racket[#t] if and only if @racket[obj] is a @racket[tracer].
}
@defproc[(call-with-tracer [report-name-base path-string?]
[proc (-> tracer? A)])
A]{
Creates a new @racket[tracer].
The @racket[tracer] will save trace reports in Open Trace Format; all trace file paths will begin with @racket[report-name-base].
}
@defform[#:id let/tracer
#:literals (tracer)
(let/tracer [tracer report-name-base] body ...)
#:contracts ([report-name-base path-string?])]{
Macro version of @racket[call-with-tracer].
Equivalent to
@racketblock[
(call-with-tracer report-name-base (lambda (tracer) body ...))
]
}
@subsection{Phases}
A @racket[phase] represents a phase of execution about which the user wishes to gather timing statistics.
@defproc[(phase? [obj any/c])
boolean?]{
Evaluates to @racket[#t] if and only if @racket[obj] is a @racket[phase].
}
@defproc[(call-with-phase [tracer tracer?]
[phase-name string?]
[proc (-> phase? A)])
A]{
Creates a new @racket[phase] attached to @racket[tracer] and named @racket[phase-name].
}
@defform[#:id let/phase
#:literals (phase)
(let/phase tracer [phase name] body ...)
#:contracts ([tracer tracer?]
[name string?])]{
Macro version of @racket[call-with-phase].
Equivalent to
@racketblock[
(call-with-phase tracer name (lambda (phase) body ...))
]
}
@subsection{Tracing}
@defproc[(call-with-phase-running [phase phase?]
[proc (-> A)])
A]{
Runs @racket[proc], associating information about its timing and execution with @racket[phase] in the trace report.
Should @racket[proc] throw an exception, @racket[call-with-phase-running] will stop tracing before propagating the exception up the stack.
}
@defform[#:id with-phase-running
#:literals (phase)
(with-phase-running phase body ...)
#:contracts ([phase phase?])]{
Macro version of @racket[call-with-phase-running].
Equivalent to
@racketblock[
(call-with-phase-running phase (lambda () body ...))
]
}
|
