DuplicateHandle (Windows Embedded CE 6.0)

1/6/2010

This function duplicates an object handle. The duplicate handle refers to the same object as the original handle. Therefore, any changes to the object are reflected through both handles.

Syntax

  BOOL DuplicateHandle(
  HANDLE hSourceProcessHandle,
  HANDLE hSourceHandle,
  HANDLE hTargetProcessHandle,
  LPHANDLE lpTargetHandle,
  DWORD dwDesiredAccess,
  BOOL bInheritHandle,
  DWORD dwOptions
);

Parameters

• hSourceProcessHandle
  [in] Handle to the process with the handle to duplicate.

• hSourceHandle
  [in] Handle to duplicate. This is an open object handle that is valid in the context of the source process. For a list of objects whose handles can be duplicated, see the Remarks section.

• hTargetProcessHandle
  [in] Handle to the process that is to receive the duplicated handle. The handle must have PROCESS_DUP_HANDLE access.

• lpTargetHandle
  [out] Pointer to a variable that receives the value of the duplicate handle. This handle value is valid in the context of the target process. Cannot be NULL.

• dwDesiredAccess
  [in] Currently ignored in Windows Embedded CE.

• bInheritHandle
  [in] Indicates whether the handle is inheritable. Must be set to FALSE.

  If FALSE, the new handle cannot be inherited.

• dwOptions
  [in] Specifies optional actions. This parameter can be any combination of the following flags which includes DUPLICATE_SAME_ACCESS.

  Value	Description
  DUPLICATE_CLOSE_SOURCE	Closes the source handle. This occurs regardless of any error status returned.
  DUPLICATE_SAME_ACCESS	The duplicate handle has the same access as the source handle. This flag must be specified for Windows Embedded CE.

Return Value

Nonzero indicates success. Zero indicates failure. To get extended error information, call GetLastError.

Remarks

Either the source process or the target process can call DuplicateHandle, which can also be invoked where the source and target process are the same.

The duplicating process uses the GetCurrentProcess function to get a handle of itself. To get the other process handle, it might be necessary to use some form of interprocess communication, for example, shared memory, to communicate the process identifier to the duplicating process. This identifier is then used in the OpenProcess function to open a handle.

If the process that calls DuplicateHandle is not the target process, the duplicating process must use interprocess communication to pass the value of the duplicate handle to the target process.

DuplicateHandle can duplicate all real handles, not just handles to events returned by CreateEvent or OpenEvent, handles to mutexes returned by CreateMutex, and handles to semaphores returned by CreateSemaphore. All real handles include: event handles, mutex handles, message queue handles, apiset handles, file handles, dbfile handles, semaphore handles, memory map handles, watchdog handles, process handles, thread handles, token handles, and any handles generated by a handle server. Also, pseudo-handles are supported.**

Requirements

See Also

Reference

Synchronization Functions
OpenProcess
CreateEvent
OpenEvent
CreateMutex
CreateProcess
GetCurrentProcess
CreateSemaphore
CreateThread
GetCurrentThread

Other Resources

CreateFileMapping
CloseHandle