Called by the client of a class object to keep an open object application in memory, allowing instances to be created more quickly.

HRESULT LockServer(

BOOL fLock
//Increments or decrements the lock count



If TRUE, increments the lock count; if FALSE, decrements the lock count.

Return Values


The specified object was either locked ( fLock = TRUE) or unlocked from memory ( fLock = FALSE).


Indicates an unspecified error.


Out of memory.


An unexpected error occurred.


controls whether an object application is kept in memory. Keeping the application alive in memory allows instances to be created more quickly.

Notes to Callers

Most clients do not need to call this function. It is provided only for the benefit of sophisticated clients that require special performance in the creation of certain kinds of objects.

Notes to Implementors

If the lock count is zero, there are no more objects in use, and the application is not under user control, then the server can be closed. One way to implement IClassFactory::LockServer is to call CoLockObjectExternal.

The process that locks the object application is responsible for unlocking it. Once the class object is released, there is no mechanism that guarantees the caller connection to the same object definition later (as in the case where a class object is registered as single-use). It is important to count all calls, not just the last one, to IClassFactory::LockServer, because calls must be balanced before attempting to release the pointer to the class object or an error results. For every call to LockServer with fLock set to TRUE, there must be a call to LockServer with fLock set to FALSE. When the lock count and the class object reference count are both zero, the class object can be freed.

See Also


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