How Geant4 can go with the Java Environment H. Yoshida Naruto U.E.

1
How Geant4 can go with the Java EnvironmentH.
Yoshida Naruto U.E.

• How C and Java can go together?
• Increasing demand for Java which is now stable
  and efficient (Java-2)
• Not an easy job but several tools are available
• JAS
• Connection with G4 was demonstrated by Tony at
  Naruto workshop
• Integrated with GAG by a new class G4UIJAG
• Glue is JNI (Java Native Interface)

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Architecture
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Interface Layers

• JAS side
• AIDA C
• JNI layer
• HistogramFactory
• Invoke JVM
• AIDA Java
• HistogramFactory
• RMI connection
• On-line histogramming

• GAG side
• Originally G4UIJAS developed by Tony
• Limited control over G4
• Beam on/off capability Exploit Java's thread
  to stop Geant4's run
• G4UIJAG class
• Complete control of G4 with GAG
• A new constructor, taking an instance of
  HistogramFactory

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JAS GAG working together

• Run GAG java gag
• Start Geant4 (GAG menu)
• Invoke JAS from GAG (GAG menu)
• Connect Geant4 with JAS (JAS menu)
• /run/beamOn (GAG menu)
• On-line histogramming (JAS)
• End (GAG)

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Demo - exampleN03

• Default gun values (0.03GeV)
• 1,000,000 events to fill LAbs
• Speed slow down by 10at on-line histogramming
  with JAS

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TODO List

• Complete (C/JNI) AIDA
• Unification of JAS and GAG
• GAG as JAS's plugin
• RMI GAG (prototype demonstrated at SLAC WS)
• Unification with Visualization, e.g., VRML