af_transaction, af_commit, af_abort - a simple transaction mechanism
int af_transaction (void)
int af_commit (void)
int af_abort (void)
These functions implement a simple transaction mechanism for AtFS. A
transaction starts with calling af_transaction. All changes to existing
ASOs performed hereafter have no immediate permanent effect. They
rather get into effect, when the transaction is ended. Calling
af_commit ends the transactions and causes all changes to be saved to
disk. af_abort aborts the transaction without saving the changes. These
will then be discarded.
Only modification of the state of existing source ASOs will be
deferred. Creation or deletion of ASOs have immediate effect,
regardless if a transaction is in effect or not. Additionally, all
operations on derived ASOs (all operations on the derived object cache)
are not affected by the transaction.
All archive files that are to be changed when the transaction is
finished are locked until the end of the transaction. The lock
prevents all other applications to perform any modifications on the
archive file. You should make sure, that ending a transaction should
never be dependent on the successful termination of another application
Upon error, -1 is returned and af_errno is set to the corresponding
Changes to the contents of busy versions have immediate effect.