Is the Adobe PDF Library thread-safe?

The Adobe PDF Library, including the .NET and Java Interfaces, are thread safe.

Any number of threads can read a PDF file at one time, but each APDFL variable is specific to the thread where that variable was created. What this means, for example, is that if your application opens PDDoc in thread A, that application cannot also open PDDoc in a different thread. We recommend that you do not share PDF Library data and resources among threads, including PDF documents, unless you are only performing read operations.