Class OpOrder.Barrier
- java.lang.Object
-
- org.apache.cassandra.utils.concurrent.OpOrder.Barrier
-
- Enclosing class:
- OpOrder
public final class OpOrder.Barrier extends java.lang.Object
This class represents a synchronisation point providing ordering guarantees on operations started against the enclosing OpOrder. When issue() is called upon it (may only happen once per Barrier), the Barrier atomically partitions new operations from those already running (by expiring the current Group), and activates its isAfter() method which indicates if an operation was started before or after this partition. It offers methods to determine, or block until, all prior operations have finished, and a means to indicate to those operations that they are blocking forward progress. SeeOpOrder
for idiomatic usage.
-
-
Constructor Summary
Constructors Constructor Description Barrier()
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
await()
wait for all operations started prior to issuing the barrier to completeOpOrder.Group
getSyncPoint()
returns the Group we are waiting on - any Group with.compareTo(getSyncPoint()) <= 0
must complete before await() returnsboolean
isAfter(OpOrder.Group group)
void
issue()
Issues (seals) the barrier, meaning no new operations may be issued against it, and expires the current Group.void
markBlocking()
Mark all prior operations as blocking, potentially signalling them to more aggressively make progress
-
-
-
Method Detail
-
isAfter
public boolean isAfter(OpOrder.Group group)
- Returns:
- true if @param group was started prior to the issuing of the barrier. (Until issue is called, always returns true, but if you rely on this behavior you are probably Doing It Wrong.)
-
issue
public void issue()
Issues (seals) the barrier, meaning no new operations may be issued against it, and expires the current Group. Must be called before await() for isAfter() to be properly synchronised.
-
markBlocking
public void markBlocking()
Mark all prior operations as blocking, potentially signalling them to more aggressively make progress
-
await
public void await()
wait for all operations started prior to issuing the barrier to complete
-
getSyncPoint
public OpOrder.Group getSyncPoint()
returns the Group we are waiting on - any Group with.compareTo(getSyncPoint()) <= 0
must complete before await() returns
-
-