Specific Notification for
Java Thread Synchronization

Tom Cargill
Consultant
Box 69, Louisville, CO 80027
www.csn.net/~cargill

Abstract

Java supports thread synchronization by means of
monitor-like primitives. The weak semantics of
Java's signaling mechanism provides little control
over the order in which threads acquire resources,
which encourages the use of the Haphazard Notification
pattern, in which an arbitrary thread is selected
from a set of threads competing for a resource.
For synchronization problems in which such arbitrary
selection of threads is unacceptable, the Specific
Notification pattern may be used to designate exactly
which thread should proceed. Specific Notification
provides an explicit mechanism for thread selection
and scheduling.