com.facebook.buck.jvm.java.tracing

Class TranslatingJavacPhaseTracer

java.lang.Object

com.facebook.buck.jvm.java.tracing.TranslatingJavacPhaseTracer

All Implemented Interfaces:

JavacPhaseTracer, AutoCloseable

public class TranslatingJavacPhaseTracer
extends Object
implements JavacPhaseTracer, AutoCloseable

A JavacPhaseTracer that translates the trace data to be more useful.

The phases of compilation are described here. The doc describes annotation processing as conceptually occuring before compilation, but actually occurring somewhat out-of-phase with the conceptual model.

Javac calls TracingTaskListener according to the conceptual model described in that document: annotation processing starts at the very beginning of the run, and ends after the last annotation processor is run in the last round of processing. Then there is one last parse and enter before going into analyze and generate. This is problematic from a performance perspective, because some of the work attributed to annotation processing would have happened regardless.

This class translates the tracing data from the conceptual model back into something that more closely matches the actual implementation:

• Parse, enter, analyze, and generate phases pass thru unchanged
• What javac traces as an annotation processing round is renamed "run annotation processors"
• Annotation processing rounds are traced from the beginning of "run annotation processors" to the beginning of the next "run annotation processors" or (for the last round) the first analyze phase
• Annotation processing is traced from the beginning of the first round to the end of the last
• If compilation ends during annotation processing (as can happen with -proc:only), it detects this (via being closed by its caller) and emits appropriate tracing

In this way, the time attributed to annotation processing is always time that would not have been spent if annotation processors were not present.

Constructor Summary

Constructors

Constructor and Description
TranslatingJavacPhaseTracer(JavacPhaseEventLogger logger)

Method Summary

Modifier and Type	Method and Description
void	beginAnalyze()
void	beginAnnotationProcessingRound()
void	beginEnter()
void	beginGenerate(String filename, String typename)
void	beginParse(String filename)
void	close()
void	endAnalyze(List<String> filenames, List<String> typenames)
void	endAnnotationProcessingRound()
void	endEnter(List<String> filenames)
void	endGenerate()
void	endParse()
void	setIsLastRound(boolean isLastRound)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TranslatingJavacPhaseTracer

public TranslatingJavacPhaseTracer(JavacPhaseEventLogger logger)

Method Detail

beginParse

public void beginParse(@Nullable
                       String filename)

Specified by:

beginParse in interface JavacPhaseTracer

endParse

public void endParse()

Specified by:

endParse in interface JavacPhaseTracer

beginEnter

public void beginEnter()

Specified by:

beginEnter in interface JavacPhaseTracer

endEnter

public void endEnter(List<String> filenames)

Specified by:

endEnter in interface JavacPhaseTracer

setIsLastRound

public void setIsLastRound(boolean isLastRound)

Specified by:

setIsLastRound in interface JavacPhaseTracer

beginAnnotationProcessingRound

public void beginAnnotationProcessingRound()

Specified by:

beginAnnotationProcessingRound in interface JavacPhaseTracer

endAnnotationProcessingRound

public void endAnnotationProcessingRound()

Specified by:

endAnnotationProcessingRound in interface JavacPhaseTracer

beginAnalyze

public void beginAnalyze()

Specified by:

beginAnalyze in interface JavacPhaseTracer

endAnalyze

public void endAnalyze(List<String> filenames,
                       List<String> typenames)

Specified by:

endAnalyze in interface JavacPhaseTracer

beginGenerate

public void beginGenerate(@Nullable
                          String filename,
                          @Nullable
                          String typename)

Specified by:

beginGenerate in interface JavacPhaseTracer

endGenerate

public void endGenerate()

Specified by:

endGenerate in interface JavacPhaseTracer

close

public void close()

Specified by:

close in interface AutoCloseable