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IHolder::Close method (comsvcs.h)

  • Article

Closes the Holder.

Syntax

HRESULT Close();

Return value

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

This closes a Resource Dispenser's Holder, after which the Resource Dispenser probably released.

Before closing, any remaining inventory is destroyed by calling back to the Resource Dispenser's IDispenserDriver::DestroyResource method.

The following sequence describes how to close down a Resource Dispenser:

  1. Obtain a reference to the Resource Dispenser (the object that exposes IDispenserDriver).
  2. Call a method in Resource Dispenser whose implementation calls IHolder::Close.
  3. IHolder::Close destroys any remaining inventory by calling back to Resource Dispenser's IDispenserDriver::DestroyResource method.
  4. IHolder::Close calls the Dispenser Manager to remove this Holder from the Holder list. (If no Holders remain, the Dispenser Manager object deletes itself.)
  5. IHolder::Close releases its reference to Resource Dispenser's IDispenserDriver interface. This is the reason you need a reference in step 1; otherwise, the Resource Dispenser would delete itself prematurely before the subsequent steps can be completed.
  6. IHolder::Close returns to the Resource Dispenser.
  7. The Resource Dispenser calls IDispenserDriver::DestroyResource. The Holder now deletes itself.
  8. The method called in step 2 now returns.
  9. Release your final reference to the Resource Dispenser, which now deletes itself.
Note that the IDispenserManager::RegisterDispenser method does not call AddRef on its pDispenserDriver object, but IHolder::Close does perform a Release on pDispenserDriver. This can cause the Resource Dispenser object to be destroyed prematurely. To prevent this premature destruction, the caller of IHolder::Close must hold a reference to the Resource Dispenser object as described in steps 1 and 5.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header comsvcs.h

See also

IDispenserDriver

IDispenserManager

IHolder