Platform SDK: DLLs, Processes, and Threads

QueryServiceLockStatus

The QueryServiceLockStatus function retrieves the lock status of the specified service control manager database.

BOOL QueryServiceLockStatus(
  SC_HANDLE hSCManager,                     // handle to SCM database
  LPQUERY_SERVICE_LOCK_STATUS lpLockStatus, // buffer
  DWORD cbBufSize,                          // size of buffer
  LPDWORD pcbBytesNeeded                    // bytes needed
);

Parameters

hSCManager
[in] Handle to the service control manager database. The OpenSCManager function returns this handle, which must have SC_MANAGER_QUERY_LOCK_STATUS access.
lpLockStatus
[out] Pointer to a QUERY_SERVICE_LOCK_STATUS structure that receives the lock status of the specified database is returned, plus the strings to which its members point.
cbBufSize
[in] Specifies the size, in bytes, of the buffer pointed to by the lpLockStatus parameter.
pcbBytesNeeded
[out] Pointer to a variable that receives the number of bytes needed to return all the lock status information, if the function fails.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

The following error codes can be set by the service control manager. Other error codes can be set by the registry functions that are called by the service control manager.

Error code Meaning
ERROR_ACCESS_DENIED The specified handle was not opened with SC_MANAGER_QUERY_LOCK_STATUS access.
ERROR_INSUFFICIENT_BUFFER There is more lock status information than would fit into the lpLockStatus buffer. The number of bytes required to get all the information is returned in the pcbBytesNeeded parameter. Nothing is written to the lpLockStatus buffer.
ERROR_INVALID_HANDLE The specified handle is invalid.

Remarks

The QueryServiceLockStatus function returns a QUERY_SERVICE_LOCK_STATUS structure that indicates whether the specified database is locked. If the database is locked, the structure provides the account name of the user that owns the lock and the length of time that the lock has been held.

A process calls the LockServiceDatabase function to acquire ownership of a service control manager database lock and the UnlockServiceDatabase function to release the lock.

Requirements

  Windows NT/2000: Requires Windows NT 3.1 or later.
  Header: Declared in Winsvc.h; include Windows.h.
  Library: Use Advapi32.lib.
  Unicode: Implemented as Unicode and ANSI versions on Windows NT/2000.

See Also

Services Overview, Service Functions, LockServiceDatabase, OpenSCManager, QUERY_SERVICE_LOCK_STATUS, UnlockServiceDatabase