/*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/publicdomain/zero/1.0/
*/
package java.util.concurrent.atomic;
/*-[
#include "java/lang/IndexOutOfBoundsException.h"
]-*/
/**
* An {@code int} array in which elements may be updated atomically.
* See the {@link java.util.concurrent.atomic} package
* specification for description of the properties of atomic
* variables.
* @since 1.5
* @author Doug Lea
*/
public class AtomicIntegerArray implements java.io.Serializable {
private static final long serialVersionUID = 2862133569453604235L;
private final int[] array;
/**
* Creates a new AtomicIntegerArray of the given length, with all
* elements initially zero.
*
* @param length the length of the array
*/
public AtomicIntegerArray(int length) {
array = new int[length];
}
/**
* Creates a new AtomicIntegerArray with the same length as, and
* all elements copied from, the given array.
*
* @param array the array to copy elements from
* @throws NullPointerException if array is null
*/
public AtomicIntegerArray(int[] array) {
// Visibility guaranteed by final field guarantees
this.array = array.clone();
}
/**
* Returns the length of the array.
*
* @return the length of the array
*/
public final int length() {
return array.length;
}
/*-[
static void CheckIdx(JavaUtilConcurrentAtomicAtomicIntegerArray *self, jint i) {
if (i < 0 || i >= self->array_->size_) {
@throw create_JavaLangIndexOutOfBoundsException_initWithNSString_(
JreStrcat("$I", @"index ", i));
}
}
static inline volatile_jint *GetPtrUnchecked(
JavaUtilConcurrentAtomicAtomicIntegerArray *self, jint i) {
return (volatile_jint *)&self->array_->buffer_[i];
}
static inline volatile_jint *GetPtrChecked(
JavaUtilConcurrentAtomicAtomicIntegerArray *self, jint i) {
CheckIdx(self, i);
return (volatile_jint *)&self->array_->buffer_[i];
}
]-*/
/**
* Gets the current value at position {@code i}.
*
* @param i the index
* @return the current value
*/
public final native int get(int i) /*-[
return __c11_atomic_load(GetPtrChecked(self, i), __ATOMIC_SEQ_CST);
]-*/;
private final native int getUnchecked(int i) /*-[
return __c11_atomic_load(GetPtrUnchecked(self, i), __ATOMIC_SEQ_CST);
]-*/;
/**
* Sets the element at position {@code i} to the given value.
*
* @param i the index
* @param newValue the new value
*/
public final native void set(int i, int newValue) /*-[
__c11_atomic_store(GetPtrChecked(self, i), newValue, __ATOMIC_SEQ_CST);
]-*/;
/**
* Eventually sets the element at position {@code i} to the given value.
*
* @param i the index
* @param newValue the new value
* @since 1.6
*/
public final native void lazySet(int i, int newValue) /*-[
__c11_atomic_store(GetPtrChecked(self, i), newValue, __ATOMIC_RELEASE);
]-*/;
/**
* Atomically sets the element at position {@code i} to the given
* value and returns the old value.
*
* @param i the index
* @param newValue the new value
* @return the previous value
*/
public final native int getAndSet(int i, int newValue) /*-[
return __c11_atomic_exchange(GetPtrChecked(self, i), newValue, __ATOMIC_SEQ_CST);
]-*/;
/**
* Atomically sets the element at position {@code i} to the given
* updated value if the current value {@code ==} the expected value.
*
* @param i the index
* @param expect the expected value
* @param update the new value
* @return true if successful. False return indicates that
* the actual value was not equal to the expected value.
*/
public final native boolean compareAndSet(int i, int expect, int update) /*-[
return __c11_atomic_compare_exchange_strong(
GetPtrChecked(self, i), &expect, update, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
]-*/;
/**
* Atomically sets the element at position {@code i} to the given
* updated value if the current value {@code ==} the expected value.
*
* <p><a href="package-summary.html#weakCompareAndSet">May fail
* spuriously and does not provide ordering guarantees</a>, so is
* only rarely an appropriate alternative to {@code compareAndSet}.
*
* @param i the index
* @param expect the expected value
* @param update the new value
* @return true if successful
*/
public final native boolean weakCompareAndSet(int i, int expect, int update) /*-[
return __c11_atomic_compare_exchange_weak(
GetPtrChecked(self, i), &expect, update, __ATOMIC_RELAXED, __ATOMIC_RELAXED);
]-*/;
/**
* Atomically increments by one the element at index {@code i}.
*
* @param i the index
* @return the previous value
*/
public final int getAndIncrement(int i) {
return getAndAdd(i, 1);
}
/**
* Atomically decrements by one the element at index {@code i}.
*
* @param i the index
* @return the previous value
*/
public final int getAndDecrement(int i) {
return getAndAdd(i, -1);
}
/**
* Atomically adds the given value to the element at index {@code i}.
*
* @param i the index
* @param delta the value to add
* @return the previous value
*/
public final native int getAndAdd(int i, int delta) /*-[
return __c11_atomic_fetch_add(GetPtrChecked(self, i), delta, __ATOMIC_SEQ_CST);
]-*/;
/**
* Atomically increments by one the element at index {@code i}.
*
* @param i the index
* @return the updated value
*/
public final int incrementAndGet(int i) {
return addAndGet(i, 1);
}
/**
* Atomically decrements by one the element at index {@code i}.
*
* @param i the index
* @return the updated value
*/
public final int decrementAndGet(int i) {
return addAndGet(i, -1);
}
/**
* Atomically adds the given value to the element at index {@code i}.
*
* @param i the index
* @param delta the value to add
* @return the updated value
*/
public final native int addAndGet(int i, int delta) /*-[
return __c11_atomic_fetch_add(GetPtrChecked(self, i), delta, __ATOMIC_SEQ_CST) + delta;
]-*/;
/**
* Returns the String representation of the current values of array.
* @return the String representation of the current values of array
*/
public String toString() {
int iMax = array.length - 1;
if (iMax == -1)
return "[]";
StringBuilder b = new StringBuilder();
b.append('[');
for (int i = 0; ; i++) {
b.append(getUnchecked(i));
if (i == iMax)
return b.append(']').toString();
b.append(',').append(' ');
}
}
}