A CommitBarrier allows multiple transactions on separate threads to
perform a single atomic commit. All of the actions performed by all of
the atomic blocks executed by members of the barrier will appear to
occur as a single atomic action, even though they are spread across
multiple threads.
A CommitBarrier allows multiple transactions on separate threads to
perform a single atomic commit. All of the actions performed by all of
the atomic blocks executed by members of the barrier will appear to
occur as a single atomic action, even though they are spread across
multiple threads.
Commit barriers can be used to implement transactors, where actions taken by multiple actors should be atomic as a single unit.
Because there is no ordering possible between the atomic blocks that
make up a commit barrier, if those transactions conflict then the only
way to avoid deadlock is to roll back all of the barrier's members. If
you observe a cancel cause of CommitBarrier.MemberCycle then this has
happened to you, and you need to run more of the logic on a single
thread inside a single transaction.
This abstraction is based on Multiverse's CountDownCommitBarrier, by
Peter Veentjer.
- Authors
Nathan Bronson
- Companion
- object
Value members
Abstract methods
Adds a new member to this coordinated commit and returns a Member
instance that should be used to execute this member's atomic block.
If the existing members of this commit barrier have already completed
(committed or rolled back) then it is not possible to join the commit
and this method will throw IllegalStateException.
Adds a new member to this coordinated commit and returns a Member
instance that should be used to execute this member's atomic block.
If the existing members of this commit barrier have already completed
(committed or rolled back) then it is not possible to join the commit
and this method will throw IllegalStateException.
If a member is added from inside a transaction and that transaction is
later rolled back, the member will be removed from the commit barrier
(by Member.cancel(CreatingTxnRolledBack)), unless
cancelOnLocalRollback is false.
- Value Params
- cancelOnLocalRollback
controls whether the newly created member will be automatically cancelled if this call to
addMemberis from inside a transaction that later rolls back
- Throws
- IllegalStateException
if this commit barrier has already been completed (committed or rolled back)