IBackgroundCopyCallback::JobError method (bits.h)

BITS calls your implementation of the JobError method when the state of the job changes to BG_JOB_STATE_ERROR.


  [in] IBackgroundCopyJob   *pJob,
  [in] IBackgroundCopyError *pError


[in] pJob

Contains job-related information, such as the number of bytes and files transferred before the error occurred. It also contains the methods to resume and cancel the job. Do not release pJob; BITS releases the interface when the JobError method returns.

[in] pError

Contains error information, such as the file being processed at the time the fatal error occurred and a description of the error. Do not release pError; BITS releases the interface when the JobError method returns.

Return value

This method should return S_OK; otherwise, BITS continues to call this method until S_OK is returned. For performance reasons, you should limit the number of times you return a value other than S_OK to a few times. As an alternative to returning an error code, consider always returning S_OK and handling the error internally. The interval at which this method is called is arbitrary.

Note that if this method fails and you called the IBackgroundCopyJob2::SetNotifyCmdLine method, the command line is executed and this method is not called again.


After you determine the cause of the error, perform one of the following options:

  • To cancel the job, call the IBackgroundCopyJob::Cancel method. The cancel request has no effect on upload jobs if the error occurred after the file was successfully uploaded. However, if the job type is BG_JOB_TYPE_UPLOAD_REPLY and the upload was successful, calling the Cancel method cancels the request for the reply data.
  • To accept the portion of the job that transferred successfully before the error occurred, call the IBackgroundCopyJob::Complete method. This option does not apply to upload jobs; you cannot complete a portion of an upload job.
  • To finish processing the job, fix the problem, and then call the IBackgroundCopyJob::Resume method.
If the job remains in an error state for 90 days (default JobInactivityTimeout Group Policy), BITS cancels the job and deletes related temporary files; job cancellation does not affect files that have been successfully uploaded.

Transient errors do not generate calls to the JobError method.

To determine whether the upload, reply, or server application portion of an upload reply job failed, call the IBackgroundCopyError::GetError method to retrieve the context in which the error occurred. The server application failed if the context is BG_ERROR_CONTEXT_REMOTE_APPLICATION. The context for upload and reply is BG_ERROR_CONTEXT_REMOTE_FILE. The reply failed if the BytesTotal member of the BG_JOB_REPLY_PROGRESS structure is not BG_SIZE_UNKNOWN. Otherwise, the upload failed.

Note  BITS supports up to four simultaneous notifications per user. If one or more applications block all four notifications for a user from returning, an application running as the same user will not receive notifications until one or more of the blocking notifications return. To reduce the chance that your callback blocks other notifications, keep your implementation short.


See the example code for the IBackgroundCopyCallback interface.


Minimum supported client Windows XP
Minimum supported server Windows Server 2003
Target Platform Windows
Header bits.h

See also