Gaudi::Guards Namespace Reference

Guards.h GaudiKernel/Guards.h Collection of very simple classes which allows to execution of some functions within the given well-defined and exception-safe context. More...

Classes
class	AuditorGuard
	It is a simple guard, which "locks" the scope for the Auditor Service is am exception-safe way. More...
class	ExceptionGuard
	The most simple guard - it execute the certain code withing typical "try {} catch" clause, used in Auditor, Algorithm, AlgTool, etc. More...

Detailed Description

Guards.h GaudiKernel/Guards.h Collection of very simple classes which allows to execution of some functions within the given well-defined and exception-safe context.

In addition these utilities allow to remove many ugly lines from many ancient base classes

The namespace contains two simple guards:

• class Gaudi::Guards::ExceptionGuard
• class Gaudi::Guards::AuditorGuard

Please note tha the class Gaudi::Utils::AlgContext is also some kind of "guard".

All these guards could work together in very collaborative way:

StatusCode Algorithm::sysInitialize ()
 {
  // create the message stream:
  MsgStream log ( msgSvc() , name() ) ;

  // lock the scope for Auditor Service
  Gaudi::Guards::AuditorGuard auditor
         ( this                           ,
           auditorSvc()                   ,   
           &IAuditorSvc::beforeInitialize ,   
           &IAuditorsvc::afterInitialize  ) ; 

  // Lock the scope for Algorithm Context Service:
  Gaudi::Utils::AlgContext context ( this , m_contextSvc ) ;

  // execute IAlgorithm::initialize within "try{}catch(..)" clause:
  Gaudi::Guards::ExceptionGuard guard
      ( this                                 , 
        std::mem_fn(&IAlgorithm::initialize) , 
        log                                  , 
        m_exceptionSvc ) ; 

  return guard ;  
 }

C++ guarantees the proper execution of all "post"-actions for all involved guards when the scope is destroyed.

Author

Vanya BELYAEV ibely.nosp@m.aev@.nosp@m.physi.nosp@m.cs.s.nosp@m.yr.ed.nosp@m.u

Date

2007-03-07