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comparison: js/src/devtools/vprof/readme.txt
js/src/devtools/vprof/readme.txt
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| 1 # This Source Code Form is subject to the terms of the Mozilla Public | |
| 2 # License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 3 # file, You can obtain one at http://mozilla.org/MPL/2.0/. | |
| 4 | |
| 5 The two files vprof.h and vprof.cpp implement a simple value-profiling mechanism. By including these two files in avmplus (or any other project), you can value profile data as you wish (currently integers). | |
| 6 | |
| 7 Usage: | |
| 8 #include "vprof.h" // in the source file you want to use it | |
| 9 | |
| 10 _vprof (value); | |
| 11 | |
| 12 At the end of the execution, for each probe you'll get the data associated with the probe, such as: | |
| 13 | |
| 14 File line avg [min : max] total count | |
| 15 ..\..\pcre\pcre_valid_utf8.cpp 182 50222.75916 [0 : 104947] 4036955604 80381 | |
| 16 | |
| 17 The probe is defined at line 182 of file pcre_vali_utf8.cpp. It was called 80381 times. The min value of the probe was 0 while its max was 10497 and its average was 50222.75916. The total sum of all values of the probe is 4036955604. Later, I plan to add more options on the spectrum of data among others. | |
| 18 | |
| 19 A few typical uses | |
| 20 ------------------ | |
| 21 | |
| 22 To see how many times a given function gets executed do: | |
| 23 | |
| 24 void f() | |
| 25 { | |
| 26 _vprof(1); | |
| 27 ... | |
| 28 } | |
| 29 | |
| 30 void f() | |
| 31 { | |
| 32 _vprof(1); | |
| 33 ... | |
| 34 if (...) { | |
| 35 _vprof(1); | |
| 36 ... | |
| 37 } else { | |
| 38 _vprof(1); | |
| 39 ... | |
| 40 } | |
| 41 } | |
| 42 | |
| 43 Here are a few examples of using the value-profiling utility: | |
| 44 | |
| 45 _vprof (e); | |
| 46 at the end of program execution, you'll get a dump of the source location of this probe, | |
| 47 its min, max, average, the total sum of all instances of e, and the total number of times this probe was called. | |
| 48 | |
| 49 _vprof (x > 0); | |
| 50 shows how many times and what percentage of the cases x was > 0, | |
| 51 that is the probablitiy that x > 0. | |
| 52 | |
| 53 _vprof (n % 2 == 0); | |
| 54 shows how many times n was an even number | |
| 55 as well as th probablitiy of n being an even number. | |
| 56 | |
| 57 _hprof (n, 4, 1000, 5000, 5001, 10000); | |
| 58 gives you the histogram of n over the given 4 bucket boundaries: | |
| 59 # cases < 1000 | |
| 60 # cases >= 1000 and < 5000 | |
| 61 # cases >= 5000 and < 5001 | |
| 62 # cases >= 5001 and < 10000 | |
| 63 # cases >= 10000 | |
| 64 | |
| 65 _nvprof ("event name", value); | |
| 66 all instances with the same name are merged | |
| 67 so, you can call _vprof with the same event name at difference places | |
| 68 | |
| 69 _vprof (e, myProbe); | |
| 70 value profile e and call myProbe (void* vprofID) at the profiling point. | |
| 71 inside the probe, the client has the predefined variables: | |
| 72 _VAL, _COUNT, _SUM, _MIN, _MAX, and the general purpose registers | |
| 73 _IVAR1, ..., IVAR4 general integer registrs | |
| 74 _I64VAR1, ..., I64VAR4 general integer64 registrs | |
| 75 _DVAR1, ..., _DVAR4 general double registers | |
| 76 _GENPTR a generic pointer that can be used by the client | |
| 77 the number of registers can be changed in vprof.h | |
| 78 | |
| 79 Named Events | |
| 80 ------------ | |
| 81 _nvprof ("event name", value); | |
| 82 all instances with the same name are merged | |
| 83 so, you can call _vprof with the same event name at difference places | |
| 84 | |
| 85 | |
| 86 Custom Probes | |
| 87 -------------- | |
| 88 You can call your own custom probe at the profiling point. | |
| 89 _vprof (v, myProbe); | |
| 90 value profile v and call myProbe (void* vprofID) at the profiling point | |
| 91 inside the probe, the client has the predefined variables: | |
| 92 _VAL, _COUNT, _SUM, _MIN, _MAX, and the general purpose registers | |
| 93 _IVAR1, ..., IVAR4 general integer registrs | |
| 94 _I64VAR1, ..., I64VAR4 general integer64 registrs | |
| 95 _DVAR1, ..., _DVAR4 general double registers | |
| 96 the number of registers can be changed in vprof.h | |
| 97 _GENPTR a generic pointer that can be used for almost anything |
