jdk.util.concurrent.atomic.LongAdder
One or more variables that together maintain an initially zero long sum. When updates (method add(long)) are contended across threads, the set of variables may grow dynamically to reduce contention. Method sum() (or, equivalently, longValue()) returns the current total combined across the variables maintaining the sum.
This class is usually preferable to AtomicLong when multiple threads update a common sum that is used for purposes such as collecting statistics, not for fine-grained synchronization control. Under low update contention, the two classes have similar characteristics. But under high contention, expected throughput of this class is significantly higher, at the expense of higher space consumption.
LongAdders can be used with a ConcurrentHashMap to maintain a scalable frequency map (a form of histogram or multiset). For example, to add a count to a ConcurrentHashMap<String,LongAdder> freqs, initializing if not already present, you can use freqs.computeIfAbsent(k -> new LongAdder()).increment();
This class extends Number, but does not define methods such as equals, hashCode and compareTo because instances are expected to be mutated, and so are not useful as collection keys.
One or more variables that together maintain an initially zero long sum. When updates (method add(long)) are contended across threads, the set of variables may grow dynamically to reduce contention. Method sum() (or, equivalently, longValue()) returns the current total combined across the variables maintaining the sum. This class is usually preferable to AtomicLong when multiple threads update a common sum that is used for purposes such as collecting statistics, not for fine-grained synchronization control. Under low update contention, the two classes have similar characteristics. But under high contention, expected throughput of this class is significantly higher, at the expense of higher space consumption. LongAdders can be used with a ConcurrentHashMap to maintain a scalable frequency map (a form of histogram or multiset). For example, to add a count to a ConcurrentHashMap<String,LongAdder> freqs, initializing if not already present, you can use freqs.computeIfAbsent(k -> new LongAdder()).increment(); This class extends Number, but does not define methods such as equals, hashCode and compareTo because instances are expected to be mutated, and so are not useful as collection keys.
->long-adderclj
(->long-adder)Constructor.
Creates a new adder with initial sum of zero.
Constructor. Creates a new adder with initial sum of zero.
addclj
(add this x)Adds the given value.
x - the value to add - long
Adds the given value. x - the value to add - `long`
double-valueclj
(double-value this)Returns the sum() as a double after a widening primitive conversion.
returns: the numeric value represented by this object after conversion
to type double. - double
Returns the sum() as a double after a widening
primitive conversion.
returns: the numeric value represented by this object after conversion
to type double. - `double`float-valueclj
(float-value this)Returns the sum() as a float after a widening primitive conversion.
returns: the numeric value represented by this object after conversion
to type float. - float
Returns the sum() as a float
after a widening primitive conversion.
returns: the numeric value represented by this object after conversion
to type float. - `float`int-valueclj
(int-value this)Returns the sum() as an int after a narrowing primitive conversion.
returns: the numeric value represented by this object after conversion
to type int. - int
Returns the sum() as an int after a narrowing
primitive conversion.
returns: the numeric value represented by this object after conversion
to type int. - `int`long-valueclj
(long-value this)Equivalent to sum().
returns: the sum - long
Equivalent to sum(). returns: the sum - `long`
resetclj
(reset this)Resets variables maintaining the sum to zero. This method may be a useful alternative to creating a new adder, but is only effective if there are no concurrent updates. Because this method is intrinsically racy, it should only be used when it is known that no threads are concurrently updating.
Resets variables maintaining the sum to zero. This method may be a useful alternative to creating a new adder, but is only effective if there are no concurrent updates. Because this method is intrinsically racy, it should only be used when it is known that no threads are concurrently updating.
sumclj
(sum this)Returns the current sum. The returned value is NOT an atomic snapshot; invocation in the absence of concurrent updates returns an accurate result, but concurrent updates that occur while the sum is being calculated might not be incorporated.
returns: the sum - long
Returns the current sum. The returned value is NOT an atomic snapshot; invocation in the absence of concurrent updates returns an accurate result, but concurrent updates that occur while the sum is being calculated might not be incorporated. returns: the sum - `long`
sum-then-resetclj
(sum-then-reset this)Equivalent in effect to sum() followed by reset(). This method may apply for example during quiescent points between multithreaded computations. If there are updates concurrent with this method, the returned value is not guaranteed to be the final value occurring before the reset.
returns: the sum - long
Equivalent in effect to sum() followed by reset(). This method may apply for example during quiescent points between multithreaded computations. If there are updates concurrent with this method, the returned value is not guaranteed to be the final value occurring before the reset. returns: the sum - `long`
to-stringclj
(to-string this)Returns the String representation of the sum().
returns: the String representation of the sum() - java.lang.String
Returns the String representation of the sum(). returns: the String representation of the sum() - `java.lang.String`
cljdoc is a website building & hosting documentation for Clojure/Script libraries
× close