ClearCase get file content causes exceptions when multiple users are trying to get the same file at the same time

When retrieving the file contents we get the file contents from cleartool and store them in a temporary file. After we have read this file, the file is deleted.

If two threads try to get the same file at the same time, we get a FileNotFoundException from thread 1 because the file was deleted by thread 2 before it was read by thread 1. We should make sure that multiple threads cannot get in each others way.