tarch::logging::ScorePLogger Class Reference

Command Line Logger. More...

#include <ScorePLogger.h>

Collaboration diagram for tarch::logging::ScorePLogger:

Public Member Functions
	~ScorePLogger ()
bool	getLogMachineName () const
	Is public as some analysis frameworks check explicitly whether these features are switched on.
bool	getLogThreadName () const
	Is public as some analysis frameworks check explicitly whether these features are switched on.
bool	getLogTrace () const
	Is public as some analysis frameworks check explicitly whether these features are switched on.
bool	getLogTimeStamp () const
	Is public as some analysis frameworks check explicitly whether these features are switched on.
void	debug (long int timestampNanoseconds, int rank, int threadId, const std::string &trace, const std::string &message)
void	info (long int timestampNanoseconds, int rank, int threadId, const std::string &trace, const std::string &message)
void	warning (long int timestampNanoseconds, int rank, int threadId, const std::string &trace, const std::string &message)
	Write Warning.
void	error (long int timestampNanoseconds, int rank, int threadId, const std::string &trace, const std::string &message)
	Write Error.
void	traceIn (long int timestampNanoseconds, int rank, int threadId, const std::string &trace, const std::string &message)
void	traceOut (long int timestampNanoseconds, int rank, int threadId, const std::string &trace, const std::string &message)
void	indent (bool indent, const std::string &trace, const std::string &message)
	Tells the logger to increment/decrement the indent.
void	close ()

Static Public Member Functions
static ScorePLogger &	getInstance ()

Private Member Functions
ScorePLogger &	operator= (const CommandLineLogger &)=delete
	Declared private since assignment does not make sense for an output class (output information mismatch).
	ScorePLogger (const ScorePLogger &)=delete
	Declared private since copying does not make sense for an output class (output information mismatch).
std::string	constructMessageString (std::string messageType, long int timestampNanoseconds, int rank, int threadId, const std::string &trace, const std::string &message)
	Construct message string.
	ScorePLogger ()
	It's a singleton.
std::string	getTimeStampHumanReadable (long int timestampNanoseconds) const

Private Attributes
tarch::multicore::BooleanSemaphore	_semaphore

Static Private Attributes
static Log	_log
static ScorePLogger	_singleton

Detailed Description

Command Line Logger.

Standard log output device. Implements the LogHandle. Usually there's only one instance of this class for only the Log type aggregates it in a static way. For a detailed description of this compiler flags please browse through the static consts of the class or the howto page.

An interesting issue is the behaviour of the command line logger in the parallel mode if debug is switched on. In this case the number of messages soon becomes unreadable for any human. Thus, the command line logger internally creates one output file rank.log for each rank and writes all the information into this file. info, warnings and errors are written (in short form) to std::cout / std::cerr, too.

If the debug mode is not set, all information is written to std::cout.

Note, that if multithreading is switched on (TBB-flag), the access to std::cout or the logfile respectively is synchronized. The other methods are not thread-safe and should be called only in safe context for defined behaviour.

Version

Revision

1.19

Author

Tobias Weinzierl, Wolfgang Eckhardt

Definition at line 54 of file ScorePLogger.h.

Constructor & Destructor Documentation

ScorePLogger() [1/2]

tarch::logging::ScorePLogger::ScorePLogger ( const ScorePLogger & )

privatedelete

Declared private since copying does not make sense for an output class (output information mismatch).

ScorePLogger() [2/2]

tarch::logging::ScorePLogger::ScorePLogger ( )

private

It's a singleton.

~ScorePLogger()

tarch::logging::ScorePLogger::~ScorePLogger

(

)

Member Function Documentation

close()

void tarch::logging::ScorePLogger::close

(

)

constructMessageString()

std::string tarch::logging::ScorePLogger::constructMessageString ( std::string messageType, long int timestampNanoseconds, int rank, int threadId, const std::string & trace, const std::string & message )

private

Construct message string.

!!! Thread Safety

The message string relies on the global field _indent. This one might change throughout the execution of this method. However, I accept such a behavior: Changing _indent throughout the message execution makes the method add the wrong number of whitespaces in front of the message. That is a 'bug' we can accept.

To satisfy Intel Inspector et al at least slightly, I copy over _indent before I actually construct the message string. So the indent can't change while we add the spaces/tabs to the output.

debug()

void tarch::logging::ScorePLogger::debug	(	long int	timestampNanoseconds,
		int	rank,
		int	threadId,
		const std::string &	trace,
		const std::string &	message )

error()

void tarch::logging::ScorePLogger::error	(	long int	timestampNanoseconds,
		int	rank,
		int	threadId,
		const std::string &	trace,
		const std::string &	message )

Write Error.

In the implementation, I call a flush on cout before I write to cerr. Otherwise, the cerr messages might overtake cout. Before the operation returns, it does a flush on cerr, too. Otherwise, the message might not occur, i.e. the application might shut down before the message is flushed to the terminal.

getInstance()

static ScorePLogger & tarch::logging::ScorePLogger::getInstance ( )

static

getLogMachineName()

bool tarch::logging::ScorePLogger::getLogMachineName

(

)

const

Is public as some analysis frameworks check explicitly whether these features are switched on.

getLogThreadName()

bool tarch::logging::ScorePLogger::getLogThreadName

(

)

const

Is public as some analysis frameworks check explicitly whether these features are switched on.

getLogTimeStamp()

bool tarch::logging::ScorePLogger::getLogTimeStamp

(

)

const

Is public as some analysis frameworks check explicitly whether these features are switched on.

getLogTrace()

bool tarch::logging::ScorePLogger::getLogTrace

(

)

const

Is public as some analysis frameworks check explicitly whether these features are switched on.

getTimeStampHumanReadable()

std::string tarch::logging::ScorePLogger::getTimeStampHumanReadable ( long int timestampNanoseconds ) const

private

indent()

void tarch::logging::ScorePLogger::indent	(	bool	indent,
		const std::string &	trace,
		const std::string &	message )

Tells the logger to increment/decrement the indent.

!!! Thread Safety

_indent is a global static field shared by all threads. If we increment or decrement it, this is first of all a read followed by a write. Consequently data races could occur and the counter could become smaller than zero. This ain't possible in the sequential code as each increment is accompanied by a decrement. The following table illustrates the race:

|| value of _indent || Thread 1 || Thread 2 | 2 | initial condition | initial condition | | enter indent(false) | enter indent(true) | | fetch indent into register | fetch indent into register | | register value -= 2 | register value += 2 | 4 | is a little bit slower | write back new value of indent | 0 | write back new value of indent |

To avoid this data race, I introduced a semaphore. This one could also be implemented with TBB's atomic construct, e.g., but I prefer the semaphor / critical section technique.

Parameters

trace	Needed in debug mode to be able to find out who called indent(false) without an indent(true)
message	Needed in debug mode to be able to find out who called indent(false) without an indent(true)

info()

void tarch::logging::ScorePLogger::info	(	long int	timestampNanoseconds,
		int	rank,
		int	threadId,
		const std::string &	trace,
		const std::string &	message )

operator=()

ScorePLogger & tarch::logging::ScorePLogger::operator= ( const CommandLineLogger & )

privatedelete

Declared private since assignment does not make sense for an output class (output information mismatch).

traceIn()

void tarch::logging::ScorePLogger::traceIn	(	long int	timestampNanoseconds,
		int	rank,
		int	threadId,
		const std::string &	trace,
		const std::string &	message )

traceOut()

void tarch::logging::ScorePLogger::traceOut	(	long int	timestampNanoseconds,
		int	rank,
		int	threadId,
		const std::string &	trace,
		const std::string &	message )

warning()

void tarch::logging::ScorePLogger::warning	(	long int	timestampNanoseconds,
		int	rank,
		int	threadId,
		const std::string &	trace,
		const std::string &	message )

Write Warning.

In the implementation, I call a flush on cout before I write to cerr. Otherwise, the cerr messages might overtake cout. Before the operation returns, it does a flush on cerr, too. Otherwise, the message might not occur, i.e. the application might shut down before the message is flushed to the terminal.

Field Documentation

_log

Log tarch::logging::ScorePLogger::_log

staticprivate

Definition at line 56 of file ScorePLogger.h.

_semaphore

tarch::multicore::BooleanSemaphore tarch::logging::ScorePLogger::_semaphore

private

Definition at line 60 of file ScorePLogger.h.

_singleton

ScorePLogger tarch::logging::ScorePLogger::_singleton

staticprivate

Definition at line 58 of file ScorePLogger.h.

---

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

• src/tarch/logging/ScorePLogger.h