UpdateHandle< T > Class Reference

a smart pointer to an object of a given type in an IProxyDict (such as StoreGateSvc). More...

#include <UpdateHandle.h>

Collaboration diagram for UpdateHandle< T >:

Detailed Description

a smart pointer to an object of a given type in an IProxyDict (such as StoreGateSvc).

It d-casts and caches locally the pointed-at object, to speed-up subsequent accesses. It can be reset by the store for asynchronous updates (IOVSvc)

IMPORTANT: UpdateHandle is not really compatible with running in multithreaded jobs. At a minimum, the payload class T must be fully thread-safe for simultaneous reads and writes (DataVector does not satisfy this). It's use will be reserved to a few special cases. If you think you need to use UpdateHandle, please consult with the core and reco groups first.

SG::UpdateHandle<T> can only access non-const proxies in StoreGate. A valid proxy must already exist in StoreGate.

Usage example:

class MyAlg : public AthAlgorithm
{
  SG::UpdateHandle<int> m_int;
};
 
MyAlg::MyAlg(...) : ..., m_int("MyIntSgKey") {
   declareProperty("IntHandle",
                   m_int = SG::UpdateHandle<int>("MyIntSgKey"),
                   "a handle to an int in StoreGate");
}
 
StatusCode MyAlg::execute()
{
  ATH_MSG_INFO("int value @[" << m_int.name() << "]="
               << *m_int);
  *m_int = 10;
  ATH_MSG_INFO("int value @[" << m_int.name() << "]="
               << *m_int);
  return StatusCode::SUCCESS;
}

For more information have a look under the package Control/AthenaExamples/AthExHelloWorld

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The documentation for this class was generated from the following file:

• UpdateHandle.h