Instrumentor Class Reference

Basic instrumentation profiler for Google Chrome tracing format. More...

#include <Instrumentor.h>

Public Member Functions
	Instrumentor ()
void	beginSession (const std::string &name, const bool storeInMemory=false, const std::string &filePath="Profiling-Results.json")
void	endSession ()
void	addProfile (const ProfileResult &result)
void	writeProfile (const ProfileResult &result)
void	writeHeader ()
void	writeFooter ()
std::string	filePath ()

Static Public Member Functions
static Instrumentor &	get ()

Private Attributes
InstrumentationSession *	_currentSession
std::string	_filePath
std::ofstream	_outputStream
int	_profileCount
std::mutex	_mutex
bool	_storeInMemory = false
std::vector< ProfileResult >	_profileResults

Detailed Description

Basic instrumentation profiler for Google Chrome tracing format.

Usage: include this header file somewhere in your code. In your most outer function (e.g. main) you have to begin profiling session with: Instrumentor::get().beginSession("Session Name"); If you pass storeInMemory=true the profileResults will be stored in memory instead of being written into the file stream which is pretty slow. Of course the in memory storage can quickly use a lot of memory depending how fine grained your profiling is. In app-demo this is done in slCreateApp.

In between you can add either PROFILE_FUNCTION(); at the beginning of any routine or PROFILE_SCOPE(scopeName) at the beginning of any scope you want to measure.

At the end of your most outer function (e.g. main) you end the session with: Instrumentor::get().endSession();

After the endSession you can drag the Profiling-Results.json file into the chrome://tracing page of the Google Chrome browser. In app-demo this is done in SLInterface::slTerminate.

Definition at line 77 of file Instrumentor.h.

Constructor & Destructor Documentation

Instrumentor()

Instrumentor::Instrumentor ( )

inline

Definition at line 80 of file Instrumentor.h.

: _currentSession(nullptr), _profileCount(0) {}

Member Function Documentation

addProfile()

void Instrumentor::addProfile ( const ProfileResult &  result )

inline

addProfile should be as fast as possible for not influencing the profiling by the profiler itself. In addition it must be thread safe.

Definition at line 119 of file Instrumentor.h.

    {
        std::lock_guard<std::mutex> lock(_mutex);
 
        if (_storeInMemory)
        {
            _profileResults.emplace_back(result);
        }
        else
        {
            writeProfile(result);
        }
    }

beginSession()

void Instrumentor::beginSession ( const std::string &  name, const bool  storeInMemory = false, const std::string &  filePath = "Profiling-Results.json"  )

inline

Definition at line 82 of file Instrumentor.h.

    {
        _storeInMemory  = storeInMemory;
        _currentSession = new InstrumentationSession{name};
        _filePath       = filePath;
 
        if (!_storeInMemory)
        {
            _outputStream.open(_filePath);
            writeHeader();
        }
    }

endSession()

void Instrumentor::endSession ( )

inline

Definition at line 97 of file Instrumentor.h.

    {
        if (_storeInMemory)
        {
            _outputStream.open(_filePath);
            writeHeader();
 
            for (auto result : _profileResults)
                writeProfile(result);
        }
 
        // end the file
        writeFooter();
        _outputStream.close();
 
        delete _currentSession;
        _currentSession = nullptr;
        _profileCount   = 0;
    }

filePath()

std::string Instrumentor::filePath ( )

inline

Definition at line 174 of file Instrumentor.h.

{ return _filePath; }

get()

static Instrumentor& Instrumentor::get ( )

inlinestatic

Definition at line 168 of file Instrumentor.h.

    {
        static Instrumentor instance;
        return instance;
    }

writeFooter()

void Instrumentor::writeFooter ( )

inline

Definition at line 162 of file Instrumentor.h.

    {
        _outputStream << "]}";
        _outputStream.flush();
    }

writeHeader()

void Instrumentor::writeHeader ( )

inline

Definition at line 156 of file Instrumentor.h.

    {
        _outputStream << "{\"otherData\": {},\"traceEvents\":[";
        _outputStream.flush();
    }

writeProfile()

void Instrumentor::writeProfile ( const ProfileResult &  result )

inline

Definition at line 133 of file Instrumentor.h.

    {
        if (_profileCount++ > 0)
            _outputStream << ",";
 
        std::string name = result.name;
        std::replace(name.begin(), name.end(), '"', '\'');
 
        _outputStream << "{";
        _outputStream << "\"cat\":\"function\",";
        _outputStream << "\"dur\":" << (result.end - result.start) << ',';
        _outputStream << "\"name\":\"" << name << "\",";
        _outputStream << "\"ph\":\"X\",";
        _outputStream << "\"pid\":0,";
        _outputStream << "\"tid\":" << result.threadID << ",";
        _outputStream << "\"ts\":" << result.start;
        _outputStream << "}";
 
        // We constantly flush in case of file writing during profiling.
        if (!_storeInMemory)
            _outputStream.flush();
    }

Member Data Documentation

_currentSession

InstrumentationSession* Instrumentor::_currentSession

private

Definition at line 178 of file Instrumentor.h.

_filePath

std::string Instrumentor::_filePath

private

Definition at line 179 of file Instrumentor.h.

_mutex

std::mutex Instrumentor::_mutex

private

Definition at line 182 of file Instrumentor.h.

_outputStream

std::ofstream Instrumentor::_outputStream

private

Definition at line 180 of file Instrumentor.h.

_profileCount

int Instrumentor::_profileCount

private

Definition at line 181 of file Instrumentor.h.

_profileResults

std::vector<ProfileResult> Instrumentor::_profileResults

private

Definition at line 184 of file Instrumentor.h.

_storeInMemory

bool Instrumentor::_storeInMemory = false

private

Definition at line 183 of file Instrumentor.h.

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The documentation for this class was generated from the following file:

• Instrumentor.h