IHostIoCompletionManager::InitializeHostOverlapped Method

Provides the host with an opportunity to initialize any custom data to append to a Win32 OVERLAPPED structure that is used for asynchronous I/O requests.


HRESULT InitializeHostOverlapped (  
    [in] void* pvOverlapped  


[in] A pointer to the Win32 OVERLAPPED structure to be included with the I/O request.

Return Value

HRESULT Description
S_OK InitializeHostOverlapped returned successfully.
HOST_E_CLRNOTAVAILABLE The common language runtime (CLR) has not been loaded into a process, or the CLR is in a state in which it cannot run managed code or process the call successfully.
HOST_E_TIMEOUT The call timed out.
HOST_E_NOT_OWNER The caller does not own the lock.
HOST_E_ABANDONED An event was canceled while a blocked thread or fiber was waiting on it.
E_FAIL An unknown catastrophic failure occurred. When a method returns E_FAIL, the CLR is no longer usable within the process. Subsequent calls to hosting methods return HOST_E_CLRNOTAVAILABLE.
E_OUTOFMEMORY Not enough memory was available to allocate the requested resource.


The Windows Platform functions use the OVERLAPPED structure to store state for asynchronous I/O requests. The CLR calls the InitializeHostOverlapped method to give the host the opportunity to append custom data to an OVERLAPPED instance.


To get to the beginning of their custom data block, hosts must set the offset to the size of the OVERLAPPED structure (sizeof(OVERLAPPED)).

A return value of E_OUTOFMEMORY indicates that the host has failed to initialize its custom data. In this case, the CLR reports an error and fails the call.


Platforms: See System Requirements.

Header: MSCorEE.h

Library: Included as a resource in MSCorEE.dll

.NET Framework Versions: Available since 2.0

See Also

ICLRIoCompletionManager Interface
GetHostOverlappedSize Method
IHostIoCompletionManager Interface