CODE STRUCTURE

Driver and User Routines The Driver Code is articulated into two main levels of calls:

A group of "system" or "driver" routines (with prefix drv...) which contain all the calls, in the correct order, to the single detector routines:

drvmain.sf --> main driver routine (called by dummy drve831.mnf )
drvinit.sf --> driver routine for control-variable initialization (deafult values to control-variables are initialized in drvdata.sf , then overwritten by reading the file e831job.nam )
drvdefn.sf --> driver routine for bitmap related issues
drvmisc.sf --> driver routine to handle non-data events
drvgeom.sf --> driver routine for geometry initialization (once-per-run)
drvunpk.sf --> driver routine for unpacking
drvanal.sf --> driver routine for event analysis and reconstruction
drvpack.sf --> driver routine for packing out events
drvprnt.sf --> driver routine for end-of-file statistics
drvstop.sf --> driver routine for job termination
drvstat.sf --> driver routine for end-of-job statistics

These routines are in the e831code/src/driver library and the general user should never have to modify them, but only to link to the corresponding objects. The actions performed by these routines are controlled by flags which the user chooses in the code namelists. The main include file for all driver routines is drvflag.inc

A group of routines which perform user specific actions:

usrinit.sf --> user routine for reading personal namelist and once-per-job initializations
usrgeom.sf --> user routine for personal geometry initializations (once-per-run)
usrunpk.sf --> user routine for personal unpacking tasks
usranal.sf --> user routine for analysis
usrpack.sf --> user routine for personal packing tasks
usrmisc.sf --> user routine to handle non-data events
usrstop.sf --> user routine for job termination

Each user routine is called at the end of the corresponding driver routine. The e831code/src/defaults_user library contains dummy versions of all these routines which you can link to to just run the program and check it is working. The library e831code/src/templates contains some examples of usrinit.sf (for histogram booking), usranal.sf (for event analysis) and usrstop.sf (for histogram saving) which you can fetch and compile into your program to produce some standard histograms for the various detectors. For your personal applications, you will want to modify one or more usr... routines. Remember to add the names of the usr... routines you modified to the object list in your makefile.

Program Flow Chart

Event Processing

Each data event is processed through three consecutive steps: unpacking, reconstruction and analysis, packing or transfer. If a fatal error is returned at any of the three steps, further processing for that event is aborted and a new event is read from the input stream.

UNPACKING is performed by the routine drvunpk.sf .
Raw or reconstructed blocks can be unpacked by setting the corresponding flags in the namelist file.
RECONSTRUCTION is performed by the routine drvanal.sf .
Reconstruction (of PWC tracks, SSD vertices, VEEs etc.) is governed by the REC... flags. Note that if you ask for an object to be reconstructed (for example, you want SSD tracks), but the reconstruction program didn't find any in that event (in our example, numtra=0), a reconstruction error is returned (currently this feature works for some blocks but not for all....).
ANALYSIS is performed by the user routine usranal.sf, which is called at the end of drvanal.sf. Obviously, to analize information from a raw or reconstructed block you first need to unpack it and/or reconstruct it.
PACKING and TRANSFERING are performed by the routine drvpack.sf .
You can transfer raw or reconstructed blocks (by setting the flags RAW... or REC...), but you can pack out only reconstructed blocks (with the flags REC... ). If a block was requested to be transfered, but it was found to be empty, a packing error is returned and the block is NOT transfered.

End of Job Statistics If by any chance the program finishes succesfully, a detailed summary of the I/O statistics for the total job and for each block is printed at the end of the log file:

EVENTS FOUND: number of events making it to drvunpk.sf.
EVENTS CORRECTLY UNPACKED: number of events were no fatal unpacking error was detected (out of the number of EVENTS FOUND)
EVENTS WITH UNPACKING ERRORS: number of events were at least one fatal unpacking error was detected (and consequently the event was aborted for further processing)
EVENTS CORRECTLY RECONSTRUCTED: number of events were no fatal reconstruction error was detected (out of the number of EVENTS CORRECTLY UNPACKED).
EVENTS WITH RECON ERRORS: number of events were at least one fatal reconstruction error was detected (and consequently the event was aborted for further processing)
EVENTS CORRECTLY PACKED: number of events were no fatal packing or transfering error was detected (out of the number of EVENTS CORRECTLY RECONSTRUCTED).
EVENTS WITH PACKING ERRORS: number of events were at least one fatal packing or transfering error was detected. Note: "transfering error" means that the block was found to be empty.
UP, RC, PK, TR: "ya" or "no" according to wheter or not the user required the block to be UnPacked, ReConstructed, PacKed, or TRansfered in the namelist (PK option is not available for raw blocks).

back to Driver main page