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diff --git a/js/src/devtools/vprof/readme.txt b/js/src/devtools/vprof/readme.txt new file mode 100644 index 000000000..f84bfc27e --- /dev/null +++ b/js/src/devtools/vprof/readme.txt @@ -0,0 +1,97 @@ +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, You can obtain one at http://mozilla.org/MPL/2.0/. + +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). + +Usage: +#include "vprof.h" // in the source file you want to use it + +_vprof (value); + +At the end of the execution, for each probe you'll get the data associated with the probe, such as: + +File line avg [min : max] total count +..\..\pcre\pcre_valid_utf8.cpp 182 50222.75916 [0 : 104947] 4036955604 80381 + +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. + +A few typical uses +------------------ + +To see how many times a given function gets executed do: + +void f() +{ + _vprof(1); + ... +} + +void f() +{ + _vprof(1); + ... + if (...) { + _vprof(1); + ... + } else { + _vprof(1); + ... + } +} + +Here are a few examples of using the value-profiling utility: + + _vprof (e); + at the end of program execution, you'll get a dump of the source location of this probe, + its min, max, average, the total sum of all instances of e, and the total number of times this probe was called. + + _vprof (x > 0); + shows how many times and what percentage of the cases x was > 0, + that is the probablitiy that x > 0. + + _vprof (n % 2 == 0); + shows how many times n was an even number + as well as th probablitiy of n being an even number. + + _hprof (n, 4, 1000, 5000, 5001, 10000); + gives you the histogram of n over the given 4 bucket boundaries: + # cases < 1000 + # cases >= 1000 and < 5000 + # cases >= 5000 and < 5001 + # cases >= 5001 and < 10000 + # cases >= 10000 + + _nvprof ("event name", value); + all instances with the same name are merged + so, you can call _vprof with the same event name at difference places + + _vprof (e, myProbe); + value profile e and call myProbe (void* vprofID) at the profiling point. + inside the probe, the client has the predefined variables: + _VAL, _COUNT, _SUM, _MIN, _MAX, and the general purpose registers + _IVAR1, ..., IVAR4 general integer registrs + _I64VAR1, ..., I64VAR4 general integer64 registrs + _DVAR1, ..., _DVAR4 general double registers + _GENPTR a generic pointer that can be used by the client + the number of registers can be changed in vprof.h + +Named Events +------------ +_nvprof ("event name", value); + all instances with the same name are merged + so, you can call _vprof with the same event name at difference places + + +Custom Probes +-------------- +You can call your own custom probe at the profiling point. +_vprof (v, myProbe); + value profile v and call myProbe (void* vprofID) at the profiling point + inside the probe, the client has the predefined variables: + _VAL, _COUNT, _SUM, _MIN, _MAX, and the general purpose registers + _IVAR1, ..., IVAR4 general integer registrs + _I64VAR1, ..., I64VAR4 general integer64 registrs + _DVAR1, ..., _DVAR4 general double registers + the number of registers can be changed in vprof.h + _GENPTR a generic pointer that can be used for almost anything |