ClfsReadPreviousRestartArea function (wdm.h)
The ClfsReadPreviousRestartArea routine reads the previous restart record relative to the current record in a read context.
Syntax
CLFSUSER_API NTSTATUS ClfsReadPreviousRestartArea(
[in] PVOID pvReadContext,
[out] PVOID *ppvRestartBuffer,
[out] PULONG pcbRestartBuffer,
[out] PCLFS_LSN plsnRestart
);
Parameters
[in] pvReadContext
A pointer to a read context obtained by a previous call to ClfsReadRestartArea.
[out] ppvRestartBuffer
A pointer to a variable that receives a pointer to the data buffer of the restart record that is read.
[out] pcbRestartBuffer
A pointer to a ULONG-typed variable that receives the size, in bytes, of the buffer pointed to by *ppvRestartBuffer. This is the length of the data buffer of the restart record that is read.
[out] plsnRestart
A pointer to a CLFS_LSN structure that receives the previous LSN of the restart record that was read.
Return value
ClfsReadPreviousRestartArea returns STATUS_SUCCESS if it succeeds; otherwise, it returns one of the error codes defined in Ntstatus.h. If there are no previous restart areas, the return value is STATUS_LOG_START_OF_LOG.
Remarks
For an explanation of CLFS concepts and terminology, see Common Log File System.
For information about reading records from CLFS streams, see Reading Data Records from a CLFS Stream and Reading Restart Records from a CLFS Stream.
Read contexts are not thread-safe. Clients are responsible for serializing access to read contexts.
Clients append restart records to a CLFS log by calling ClfsWriteRestartArea.
With the ReadPreviousLogRestartArea routine, clients can implement a form of fuzzy checkpointing. For example, the checkpoint state could consist of the log records delimited by two or more restart records.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available in Windows Server 2003 R2, Windows Vista, and later versions of Windows. |
| Target Platform | Desktop |
| Header | wdm.h (include Wdm.h) |
| Library | Clfs.lib |
| DLL | Clfs.sys |
| IRQL | <= APC_LEVEL |