A Few Recent Updates To DANA

1
A Few Recent Updates To DANA

• GlueX Software meeting
• July 26, 2005
• David Lawrence

2
Shared Objects

• DANA can use shared objects for
• Event Sources
• Factories

It does this using the libdl library (dlopen,
dlsym, )
3
Shared Objects

• Command line
• Attaching a single object
• hd_ana --solibhddm_shlib.a hdgeant.hddm
• Attaching all objects in a directory
• hd_ana --sodir/tmp/myshlibs hdgeant.hddm

• sodir can be a relative or full path
• filenames of the form lib.so will be attached

4
Shared Objects

• Creating a shared object
• Makefile

PACKAGES ROOTDANA MODULE_NAME
hddm_shlib include (HALLD_HOME)/src/BMS/Makefile
.shlib
Makes the file libhddm_shlib.so from all files in
directory.
5
Shared Objects

• Source code for shared object

include DApplication.h extern "C" extern
GetDEventSourceType_t GetDEventSourceType extern
MakeDEventSource_t MakeDEventSource extern
InitFactories_t InitFactories const char
GetDEventSourceType(void)return
"DEventSourceHDDM" DEventSource
MakeDEventSource(const char name) return new
DEventSourceHDDM(name) void
InitFactories(DEventLoop eventLoop) eventLoop-
gtAddFactory(new DFactory_DBCALHit())
6
Shared Objects

• Using shared objects can be dangerous!
• The shared object mechanism in DANA is not
  intended for normal use.
• It could potentially provide a lot of benefit
  during code development or in certain
  circumstances, a more convenient path to legacy
  compatibility.

7
Using Multiple Threads

• Command Line
• hd_ana --nthreads4 hdgeant.hddm
• C Source

// Instantiate a DApplication object DApplication
app(narg, argv) // Run though all
events app.Run(myproc, 10)
Command line takes precedence!
8
Using Multiple Threads

• Writing thread-safe code
• Dont use static or global variables
• Wrap ROOT calls in TThreadLock() and
  TThreadUnLock()
• Dont wrap your whole routine (or even a single
  factory) with a mutex!!

9
Factory Tags

• Tags can be used to distinguish two factories
  which produce the same data type.
• For example

vectorltconst DParticlegt particles vectorltconst
DParticlegt kaons loop-gtGet(particles) loop-gtGe
t(kaons, kaons)
10
Factory Tags

• Tagging a factory
• in the factorys header file
• DFactory_Kaon.h

const char Tag(void)return kaons"
11
Class Creation Scripts
located in HALLD_HOME/scripts

• mkclass - makes a class
• myclass.h
• myclass.cc
• mkfactory - makes a factory
• mydata.h
• DFactory_mydata.h
• DFactory_mydata.cc
• mkprocessor - makes an event processor
• DEventProcessor_name.h
• DEventProcessor_name.cc