This is maintenance repository of JSR-166 specifications. For further information, go to: http://altair.cs.oswego.edu/mailman/listinfo/concurrency-interest.
JSR-166 introduces package java.util.concurrent
containing utility classes commonly useful in concurrent
programming. Like package java.util
, it includes a few small
standardized extensible frameworks, as well as other classes that
provide useful functionality and are otherwise tedious or difficult to
implement.
JSR-166 focuses on breadth, providing critical functionality useful across a wide range of concurrent programming styles and applications, ranging from low-level atomic operations, to customizable locks and synchronization aids, to various concurrent data structures, to high-level execution agents including thread pools. This diversity reflects the range of contexts in which developers of concurrent programs have been found to require or desire support not previously available in J2SE, while also keeping the resulting package small; providing only functionality that has been found to be worthwhile to standardize.
Descriptions and brief motivations for the main components may be found in the associated package documentation. JSR-166 also includes a few changes and additions in packages outside of java.util.concurrent. Here are brief descriptions.
java.util
. Existing class {@link java.util.LinkedList} is
adapted to support Queue, and a new non-thread-safe {@link
java.util.PriorityQueue} is added.
interrupt
method is the only way to
re-assert a thread's interruption status (and in the case of
self-interruption has no other effect than this). The check here
previously caused unjustifiable and uncontrollable failures when
restricted code invoked library code that must reassert interruption
to correctly propagate status when encountering some
InterruptedExceptions
.
destroy
method, which has never been implemented,
has finally been deprecated. This is just a spec change, reflecting
the fact that the reason it has never been implemented is that
it was undesirable and unworkable.
nanoTime
is added to {@link java.lang.System}. It
provides a high-precision timing facility that is distinct from and
uncoordinated with System.currentTimeMillis
.