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