Concurrent modification of the same PDF by multiple users.

Q: When I open the same PDF with 2 different users and both users
modify it (in the same process), the PDF was corrupt when the 2nd user
saves the document.

It’s possible to lock the PDF when open it?

How can detect if the PDF is opened by another user?

A: This could happen if you are modifying the same file from multiple
threads within the same process. In this case you need to ensure that
document is locked (perhaps using pdftron.PDF.PDFDoc.Lock()/Unlock()
or some other synchronization?). If you are modifying the same file
prom multiple processes the OS should lock the file for you so you
would not need to do anything extra.