Participating in Error Record Persistence

To participate in error record persistence, a PSHED plug-in must implement the following callback functions:

WriteErrorRecord

ReadErrorRecord

ClearErrorRecord

The following code example shows how to implement these callback functions.

//
// The PSHED plug-in's WriteErrorRecord callback function
//
NTSTATUS
  WriteErrorRecord(
    IN OUT PVOID PluginContext,
    IN ULONG Flags,
    IN ULONG RecordLength,
    IN PWHEA_ERROR_RECORD ErrorRecord
    )
{
  // Check if dummy write operation
  if (Flags & WHEA_WRITE_FLAG_DUMMY)
  {
    return STATUS_SUCCESS;
  }

  // Write the error record to the persistent data storage
  ...

  // If successful, return success status
  if (...)
  {
    return STATUS_SUCCESS;
  }

  // Failed to write the error record
  else
  {
    return STATUS_UNSUCCESSFUL;
  }
}

//
// The PSHED plug-in's ReadErrorRecord callback function
//
NTSTATUS
  ReadErrorRecord(
    IN OUT PVOID PluginContext,
    IN ULONG Flags,
    IN ULONGLONG ErrorRecordId,
    OUT ULONGLONG NextErrorRecordId,
    IN OUT PULONG RecordLength,
    IN OUT PWHEA_ERROR_RECORD ErrorRecord
    )
{
  ULONG Length;
  PWHEA_ERROR_RECORD Record;

  // Check if an error record that matches the
  // identifier in the ErrorRecordId parameter
  // exists in the persistent data storage
  if (...)
  {
    // Retrieve the length of the specified error
    // record from the persistent data storage
    Length = ...;

    // Check if the buffer is too small to contain
    // the error record
    if (*RecordLength < Length)
    {
      // Set the RecordLength to the required length
      *RecordLength = Length;

      // Return error status
      return STATUS_BUFFER_TOO_SMALL;
    }

    // Retrieve the error record from the
    // persistent data storage and copy it
    // into the buffer pointed to by the
    // ErrorRecord parameter.
    ...

    // If successful
    if (...)
    {
      // Set RecordLength to the length of the
      // error record
      *RecordLength = Length;

      // Check if there are any other error records
      // in the persistent data storage
      if (...)
      {
        // Return the identifier of the next
        // error record
        *NextErrorRecordId = ...;
      }

      // No other error records
      else
      {
        // Return the identifier of this error record
        *NextErrorRecordId = ErrorRecordId;
      }

      // Return success status
      return STATUS_SUCCESS;
    }

    // Failed to read the error record
    else
    {
      // Return error status
      return STATUS_UNSUCCESSFUL;
    }
  }

  // The error record does not exist in the
  // persistent data storage
  else
  {
    // Return error status
    return STATUS_OBJECT_NOT_FOUND;
  }
}

//
// The PSHED plug-in&#39;s ClearErrorRecord callback function
//
NTSTATUS
  ClearErrorRecord(
    IN OUT PVOID PluginContext,
    IN ULONG Flags,
    IN ULONGLONG ErrorRecordId
    )
{
  // Clear the error record that matches the specified
  // error record identifier from the persistent data
  // storage.
  ...

  // If successful, return success status
  if (...)
  {
    return STATUS_SUCCESS;
  }

  // Failed to clear the error record
  else
  {
    return STATUS_UNSUCCESSFUL;
  }
}

A PSHED plug-in that participates in error record persistence must specify the PshedFAErrorRecordPersistence flag when it registers itself with the operating system.

For more information about error record persistence, see Error Record Persistence Mechanism.


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