IWbemHiPerfProvider::CreateRefreshableObject method (wbemprov.h)

The IWbemHiPerfProvider::CreateRefreshableObject method requests a refreshable instance object. The WMI Refresher calls IWbemHiPerfProvider::CreateRefreshableObject in response to a client request to the IWbemConfigureRefresher::AddObjectByPath or IWbemConfigureRefresher::AddObjectByTemplate interfaces. The provider reads the key from the supplied template object and supplies an object in the ppRefreshable parameter that will be refreshed whenever the refresh method on pRefresher is called. The provider associates the refreshable object with the supplied refresher, obtained from an earlier call to IWbemHiPerfProvider::CreateRefresher.

Syntax

HRESULT CreateRefreshableObject(
  [in]  IWbemServices     *pNamespace,
  [in]  IWbemObjectAccess *pTemplate,
  [in]  IWbemRefresher    *pRefresher,
  [in]  long              lFlags,
  [in]  IWbemContext      *pContext,
  [out] IWbemObjectAccess **ppRefreshable,
  [out] long              *plId
);

Parameters

[in] pNamespace

An IWbemServices pointer back into Windows Management, which can service any request made by the provider. If the pointer must call back into WMI during its execution, the provider calls AddRef on it.

[in] pTemplate

Pointer to a IWbemObjectAccess object that contains the template.

[in] pRefresher

Pointer to a IWbemRefresher object that contains a refresher obtained by calling IWbemHiPerfProvider::CreateRefresher.

[in] lFlags

Reserved. This parameter must be 0.

[in] pContext

Typically NULL; otherwise, a pointer to an IWbemContext object that is required by one or more dynamic class providers. The values in the context object must be specified in the specific provider documentation. For more information about this parameter, see Making Calls to WMI.

[out] ppRefreshable

Pointer that holds the reference to a IWbemObjectAccess object, which will contain the refreshable object.

[out] plId

Pointer to an integer returned by the provider that uniquely identifies this refreshable object.

Return value

This method returns an HRESULT indicating the status of the method call. The following list lists the value contained within an HRESULT.

Remarks

The supplied instance template will contain an object with the key properties filled out. The returned object should be a unique, refreshable object. The provider must not touch the refreshable object except during a refresh operation. Your provider must not access the returned object, unless the object owning the refresher restores the object. The key properties of the supplied instance template will be filled out. The provider should also validate the instance path.

Examples

The following code example describes how to implement CreateRefreshableObject.

HRESULT CMyHiPerfProvider::CreateRefreshableObject(
  /* [in] */IWbemServices *pNamespace,
  /* [in] */IWbemObjectAccess *pTemplate,
  /* [in] */IWbemRefresher *pRefresher,
  /* [in] */long lFlags,
  /* [in] */IWbemContext *pCtx,
  /* [out] */IWbemObjectAccess **ppRefreshable,
  /* [out] */ long *plId
)
{
  // Use a private interface defined
  // to talk with the refresher. You must define
  // the IMyRefresher interface.
  IMyRefresher* pMyRefr = NULL;

  HRESULT hres = pRefresher->QueryInterface(
    IID_IMyRefresher,
    (void**) &pMyRefr );

  if ( SUCCEEDED( hres ) )
  {
    // Check for a valid instance.
    // You must implement the ValidateInst function.
    if ( ValidateInst( pTemplate ) )
    {
      IWbemClassObject* pTemplateObj = NULL;
      IWbemClassObject* pCloneObj = NULL;
      IWbemObjectAccess* pCloneAcc = NULL;

      // Clone the object, then get an
      // IWbemObjectAccess pointer.
      pTemplate->QueryInterface(
        IID_IWbemClassObject,
        (void**) &pTemplateObj );

      pTemplateObj->Clone( &pCloneObj );

      pCloneObj->QueryInterface(
        IID_IWbemObjectAccess,
        (void**) &pCloneAcc );

      // Generate a unique identifier.
      // For example, use:
      /**plId = InterlockedIncrement( &m_lLastId );*/

      // Add the object to an array of
      // objects to refresh.
      //For example, use:
      /*pMyRefr->AddInstance( *plId, pCloneAcc );*/

      // Maintains AddRef from QI
      *ppRefreshable = pCloneAcc;

      pTemplateObj->Release();
      pCloneObj->Release();
    }
    else
    {
      hres = WBEM_E_NOT_FOUND;
    }

    pMyRefr->Release();
  }

  return hres;
}

Requirements

See also

Developing a WMI Provider

IWbemHiPerfProvider

Making an Instance Provider into a High-Performance Provider

Performance Counter Provider

Writing an Instance Provider