FSCTL_TXFS_LIST_TRANSACTIONS control code

Returns a list of all the transactions currently involved in the specified resource manager. If the function fails with ERROR_MORE_DATA, it returns the length of the buffer required to hold the complete list of transactions at the time of this call.

BOOL DeviceIoControl(
  (HANDLE) hDevice,              // handle to device
  FSCTL_TXFS_LIST_TRANSACTIONS, // dwIoControlCode
  NULL,                          // lpInBuffer
  0,                             // nInBufferSize
  (LPVOID) lpOutBuffer,          // output buffer
  (DWORD) nOutBufferSize,        // size of output buffer
  (LPDWORD) lpBytesReturned,     // number of bytes returned
  (LPOVERLAPPED) lpOverlapped    // OVERLAPPED structure
);

Parameters

To perform this operation, call the DeviceIoControl function with the following parameters.

hDevice

A handle to the root of the resource manager to query.

dwIoControlCode

The control code for the operation. Use FSCTL_TXFS_LIST_TRANSACTIONS for this operation.

lpInBuffer

Not used with this operation; set to NULL.

nInBufferSize

Not used with this operation; set to 0 (zero).

lpOutBuffer

A pointer to the output buffer, a TXFS_LIST_TRANSACTIONS structure.

nOutBufferSize

The size of the output buffer, in bytes.

lpBytesReturned

A pointer to a variable that receives the size of the data stored in the output buffer, in bytes.

If lpOverlapped is NULL, lpBytesReturned cannot be NULL. Even when an operation returns no output data and lpOutBuffer is NULL, DeviceIoControl makes use of lpBytesReturned. After such an operation, the value of lpBytesReturned is meaningless.

If lpOverlapped is not NULL, lpBytesReturned can be NULL. If this parameter is not NULL and the operation returns data, lpBytesReturned is meaningless until the overlapped operation has completed. To retrieve the number of bytes returned, call GetOverlappedResult. If hDevice is associated with an I/O completion port, you can retrieve the number of bytes returned by calling GetQueuedCompletionStatus.

lpOverlapped

A pointer to an OVERLAPPED structure.

If hDevice was opened without specifying FILE_FLAG_OVERLAPPED, lpOverlapped is ignored.

If hDevice was opened with the FILE_FLAG_OVERLAPPED flag, the operation is performed as an overlapped (asynchronous) operation. In this case, lpOverlapped must point to a valid OVERLAPPED structure that contains a handle to an event object. Otherwise, the function fails in unpredictable ways.

For overlapped operations, DeviceIoControl returns immediately, and the event object is signaled when the operation has been completed. Otherwise, the function does not return until the operation has been completed or an error occurs.

Return value

If the operation completes successfully, DeviceIoControl returns a nonzero value.

If the operation fails or is pending, DeviceIoControl returns 0 (zero). To get extended error information, call GetLastError.

If the operation fails and GetLastError returns ERROR_MORE_DATA, the BufferSizeRequired member in the output buffer indicates how big a buffer is needed.

Remarks

FSCTL_TXFS_LIST_TRANSACTIONS is a synchronous operation.

The number of transactions returned from one call to the next can change depending on the number of active transactions at any given point in time. If this call returns a request for a larger buffer, that size may or may not be adequate for the next call, based on the number of active transactions at the time of the next call.

Requirements

See also

CreateFile

DeviceIoControl

TXFS_LIST_TRANSACTIONS

TXFS_LIST_TRANSACTIONS_ENTRY

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Build date: 9/10/2011