Spotlight

The most common cause of FSDeleteObject temporarily failing with fBsyErr is that Spotlight is in the process of indexing the file. If you modify a file, close it, and then immediately try to delete it using FSDeleteObject, it's quite possible that the Spotlight indexer will have it open and you'll get fBsyErr.

There are numerous ways to prevent this problem.

1. If, when you create the file, you know that it shouldn't be indexed (for example, in your case, you know that it's a safe save temporary), create it somewhere that Spotlight won't index, or with a name that causes it not to be indexed.

   Places that won't get indexed by Spotlight include:

   • The standard UNIX temporary directory (/tmp)

   • The temporary items folder returned by Folder Manager with the kTemporaryFolderType selector

   Names that won't get indexed include:

   • Names beginning with a "."

   • Names ending with ".noindex"

   These lists are not exhaustive (r. 4823573) because the full list of what Spotlight doesn't index is likely to change over time. However, if you use one of the techniques listed above, you should be compatible with any future system.

2. The preceeding technique won't work if you can't tell, in advance, whether the file will persist (and need to be indexed) or not. In that case, if you know you've modified the file but it doesn't need to persist, delete the file (using unlink or FSUnlinkObject) before you close it. That way the Spotlight indexer will never be invoked.

3. Alternatively, always delete files using unlink or FSUnlinkObject.

4. When FSDeleteObject fails with fBsyErr, delay for a short period of time and then retry.

Anti-Virus Scanners

Some third party anti-virus scanners can also trigger this problem. When you close a modified file, the anti-virus scanner immediately starts to check it for viruses. If it's still checking when you try to delete the file, FSDeleteObject will fail with fBsyErr.

In this case, the first workaround (option 1 in the previous section) will not work because there are no standard locations or names that prevent anti-virus scanning; you will have to use one of the other options.