Last week I’ve worked with Jeff Johnson to fix a small RPM issue which was bothering us for quite some time. Until this change, RPM was accepting two transactions to be run at the same time but, unfortunately, this might put the database in an inconsistent state, and some headers might get lost while restoring it with –rebuilddb.
Our fix was rather simple, based on fcntl() locking while transactions are being committed to the system. This should be enough, protecting databases while the issue is not fixed The Right Way (the time consuming one ).
Developers of applications linked with RPM should not worry about additional errors, since the current behavior is to wait for the lock to be released while entering in the transaction committing function.