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From agoncha...@apache.org
Subject [06/11] incubator-ignite git commit: IGNITE-45 - Renamed jdk8.backport to jsr166
Date Mon, 23 Mar 2015 03:52:14 GMT
http://git-wip-us.apache.org/repos/asf/incubator-ignite/blob/2cb81f9b/modules/core/src/main/java/org/jdk8/backport/Striped64_8.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/jdk8/backport/Striped64_8.java b/modules/core/src/main/java/org/jdk8/backport/Striped64_8.java
deleted file mode 100644
index 846f0e3..0000000
--- a/modules/core/src/main/java/org/jdk8/backport/Striped64_8.java
+++ /dev/null
@@ -1,346 +0,0 @@
-/*
- * 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/
- */
-
-/*
- * The initial version of this file was copied from JSR-166:
- * http://gee.cs.oswego.edu/dl/concurrency-interest/
- */
-
-package org.jdk8.backport;
-
-import java.util.*;
-
-/**
- * A package-local class holding common representation and mechanics
- * for classes supporting dynamic striping on 64bit values. The class
- * extends Number so that concrete subclasses must publicly do so.
- */
-@SuppressWarnings("ALL")
-abstract class Striped64_8 extends Number {
-    /*
-     * This class maintains a lazily-initialized table of atomically
-     * updated variables, plus an extra "base" field. The table size
-     * is a power of two. Indexing uses masked per-thread hash codes.
-     * Nearly all declarations in this class are package-private,
-     * accessed directly by subclasses.
-     *
-     * Table entries are of class Cell; a variant of AtomicLong padded
-     * to reduce cache contention on most processors. Padding is
-     * overkill for most Atomics because they are usually irregularly
-     * scattered in memory and thus don't interfere much with each
-     * other. But Atomic objects residing in arrays will tend to be
-     * placed adjacent to each other, and so will most often share
-     * cache lines (with a huge negative performance impact) without
-     * this precaution.
-     *
-     * In part because Cells are relatively large, we avoid creating
-     * them until they are needed.  When there is no contention, all
-     * updates are made to the base field.  Upon first contention (a
-     * failed CAS on base update), the table is initialized to size 2.
-     * The table size is doubled upon further contention until
-     * reaching the nearest power of two greater than or equal to the
-     * number of CPUS. Table slots remain empty (null) until they are
-     * needed.
-     *
-     * A single spinlock ("busy") is used for initializing and
-     * resizing the table, as well as populating slots with new Cells.
-     * There is no need for a blocking lock: When the lock is not
-     * available, threads try other slots (or the base).  During these
-     * retries, there is increased contention and reduced locality,
-     * which is still better than alternatives.
-     *
-     * Per-thread hash codes are initialized to random values.
-     * Contention and/or table collisions are indicated by failed
-     * CASes when performing an update operation (see method
-     * retryUpdate). Upon a collision, if the table size is less than
-     * the capacity, it is doubled in size unless some other thread
-     * holds the lock. If a hashed slot is empty, and lock is
-     * available, a new Cell is created. Otherwise, if the slot
-     * exists, a CAS is tried.  Retries proceed by "double hashing",
-     * using a secondary hash (Marsaglia XorShift) to try to find a
-     * free slot.
-     *
-     * The table size is capped because, when there are more threads
-     * than CPUs, supposing that each thread were bound to a CPU,
-     * there would exist a perfect hash function mapping threads to
-     * slots that eliminates collisions. When we reach capacity, we
-     * search for this mapping by randomly varying the hash codes of
-     * colliding threads.  Because search is random, and collisions
-     * only become known via CAS failures, convergence can be slow,
-     * and because threads are typically not bound to CPUS forever,
-     * may not occur at all. However, despite these limitations,
-     * observed contention rates are typically low in these cases.
-     *
-     * It is possible for a Cell to become unused when threads that
-     * once hashed to it terminate, as well as in the case where
-     * doubling the table causes no thread to hash to it under
-     * expanded mask.  We do not try to detect or remove such cells,
-     * under the assumption that for long-running instances, observed
-     * contention levels will recur, so the cells will eventually be
-     * needed again; and for short-lived ones, it does not matter.
-     */
-
-    /**
-     * Padded variant of AtomicLong supporting only raw accesses plus CAS.
-     * The value field is placed between pads, hoping that the JVM doesn't
-     * reorder them.
-     *
-     * JVM intrinsics note: It would be possible to use a release-only
-     * form of CAS here, if it were provided.
-     */
-    static final class Cell {
-        volatile long p0, p1, p2, p3, p4, p5, p6;
-        volatile long value;
-        volatile long q0, q1, q2, q3, q4, q5, q6;
-        Cell(long x) { value = x; }
-
-        final boolean cas(long cmp, long val) {
-            return UNSAFE.compareAndSwapLong(this, valueOffset, cmp, val);
-        }
-
-        // Unsafe mechanics
-        private static final sun.misc.Unsafe UNSAFE;
-        private static final long valueOffset;
-        static {
-            try {
-                UNSAFE = getUnsafe();
-                Class<?> ak = Cell.class;
-                valueOffset = UNSAFE.objectFieldOffset
-                    (ak.getDeclaredField("value"));
-            } catch (Exception e) {
-                throw new Error(e);
-            }
-        }
-
-    }
-
-    /**
-     * Holder for the thread-local hash code. The code is initially
-     * random, but may be set to a different value upon collisions.
-     */
-    static final class HashCode {
-        static final Random rng = new Random();
-        int code;
-        HashCode() {
-            int h = rng.nextInt(); // Avoid zero to allow xorShift rehash
-            code = (h == 0) ? 1 : h;
-        }
-    }
-
-    /**
-     * The corresponding ThreadLocal class
-     */
-    static final class ThreadHashCode extends ThreadLocal<HashCode> {
-        public HashCode initialValue() { return new HashCode(); }
-    }
-
-    /**
-     * Static per-thread hash codes. Shared across all instances to
-     * reduce ThreadLocal pollution and because adjustments due to
-     * collisions in one table are likely to be appropriate for
-     * others.
-     */
-    static final ThreadHashCode threadHashCode = new ThreadHashCode();
-
-    /** Number of CPUS, to place bound on table size */
-    static final int NCPU = Runtime.getRuntime().availableProcessors();
-
-    /**
-     * Table of cells. When non-null, size is a power of 2.
-     */
-    transient volatile Cell[] cells;
-
-    /**
-     * Base value, used mainly when there is no contention, but also as
-     * a fallback during table initialization races. Updated via CAS.
-     */
-    transient volatile long base;
-
-    /**
-     * Spinlock (locked via CAS) used when resizing and/or creating Cells.
-     */
-    transient volatile int busy;
-
-    /**
-     * Package-private default constructor
-     */
-    Striped64_8() {
-    }
-
-    /**
-     * CASes the base field.
-     */
-    final boolean casBase(long cmp, long val) {
-        return UNSAFE.compareAndSwapLong(this, baseOffset, cmp, val);
-    }
-
-    /**
-     * CASes the busy field from 0 to 1 to acquire lock.
-     */
-    final boolean casBusy() {
-        return UNSAFE.compareAndSwapInt(this, busyOffset, 0, 1);
-    }
-
-    /**
-     * Computes the function of current and new value. Subclasses
-     * should open-code this update function for most uses, but the
-     * virtualized form is needed within retryUpdate.
-     *
-     * @param currentValue the current value (of either base or a cell)
-     * @param newValue the argument from a user update call
-     * @return result of the update function
-     */
-    abstract long fn(long currentValue, long newValue);
-
-    /**
-     * Handles cases of updates involving initialization, resizing,
-     * creating new Cells, and/or contention. See above for
-     * explanation. This method suffers the usual non-modularity
-     * problems of optimistic retry code, relying on rechecked sets of
-     * reads.
-     *
-     * @param x the value
-     * @param hc the hash code holder
-     * @param wasUncontended false if CAS failed before call
-     */
-    final void retryUpdate(long x, HashCode hc, boolean wasUncontended) {
-        int h = hc.code;
-        boolean collide = false;                // True if last slot nonempty
-        for (;;) {
-            Cell[] as; Cell a; int n; long v;
-            if ((as = cells) != null && (n = as.length) > 0) {
-                if ((a = as[(n - 1) & h]) == null) {
-                    if (busy == 0) {            // Try to attach new Cell
-                        Cell r = new Cell(x);   // Optimistically create
-                        if (busy == 0 && casBusy()) {
-                            boolean created = false;
-                            try {               // Recheck under lock
-                                Cell[] rs; int m, j;
-                                if ((rs = cells) != null &&
-                                    (m = rs.length) > 0 &&
-                                    rs[j = (m - 1) & h] == null) {
-                                    rs[j] = r;
-                                    created = true;
-                                }
-                            } finally {
-                                busy = 0;
-                            }
-                            if (created)
-                                break;
-                            continue;           // Slot is now non-empty
-                        }
-                    }
-                    collide = false;
-                }
-                else if (!wasUncontended)       // CAS already known to fail
-                    wasUncontended = true;      // Continue after rehash
-                else if (a.cas(v = a.value, fn(v, x)))
-                    break;
-                else if (n >= NCPU || cells != as)
-                    collide = false;            // At max size or stale
-                else if (!collide)
-                    collide = true;
-                else if (busy == 0 && casBusy()) {
-                    try {
-                        if (cells == as) {      // Expand table unless stale
-                            Cell[] rs = new Cell[n << 1];
-                            for (int i = 0; i < n; ++i)
-                                rs[i] = as[i];
-                            cells = rs;
-                        }
-                    } finally {
-                        busy = 0;
-                    }
-                    collide = false;
-                    continue;                   // Retry with expanded table
-                }
-                h ^= h << 13;                   // Rehash
-                h ^= h >>> 17;
-                h ^= h << 5;
-            }
-            else if (busy == 0 && cells == as && casBusy()) {
-                boolean init = false;
-                try {                           // Initialize table
-                    if (cells == as) {
-                        Cell[] rs = new Cell[2];
-                        rs[h & 1] = new Cell(x);
-                        cells = rs;
-                        init = true;
-                    }
-                } finally {
-                    busy = 0;
-                }
-                if (init)
-                    break;
-            }
-            else if (casBase(v = base, fn(v, x)))
-                break;                          // Fall back on using base
-        }
-        hc.code = h;                            // Record index for next time
-    }
-
-
-    /**
-     * Sets base and all cells to the given value.
-     */
-    final void internalReset(long initialValue) {
-        Cell[] as = cells;
-        base = initialValue;
-        if (as != null) {
-            int n = as.length;
-            for (int i = 0; i < n; ++i) {
-                Cell a = as[i];
-                if (a != null)
-                    a.value = initialValue;
-            }
-        }
-    }
-
-    // Unsafe mechanics
-    private static final sun.misc.Unsafe UNSAFE;
-    private static final long baseOffset;
-    private static final long busyOffset;
-    static {
-        try {
-            UNSAFE = getUnsafe();
-            Class<?> sk = Striped64_8.class;
-            baseOffset = UNSAFE.objectFieldOffset
-                (sk.getDeclaredField("base"));
-            busyOffset = UNSAFE.objectFieldOffset
-                (sk.getDeclaredField("busy"));
-        } catch (Exception e) {
-            throw new Error(e);
-        }
-    }
-
-    /**
-     * Returns a sun.misc.Unsafe.  Suitable for use in a 3rd party package.
-     * Replace with a simple call to Unsafe.getUnsafe when integrating
-     * into a jdk.
-     *
-     * @return a sun.misc.Unsafe
-     */
-    private static sun.misc.Unsafe getUnsafe() {
-        try {
-            return sun.misc.Unsafe.getUnsafe();
-        } catch (SecurityException se) {
-            try {
-                return java.security.AccessController.doPrivileged
-                    (new java.security
-                        .PrivilegedExceptionAction<sun.misc.Unsafe>() {
-                        public sun.misc.Unsafe run() throws Exception {
-                            java.lang.reflect.Field f = sun.misc
-                                .Unsafe.class.getDeclaredField("theUnsafe");
-                            f.setAccessible(true);
-                            return (sun.misc.Unsafe) f.get(null);
-                        }});
-            } catch (java.security.PrivilegedActionException e) {
-                throw new RuntimeException("Could not initialize intrinsics",
-                    e.getCause());
-            }
-        }
-    }
-}

http://git-wip-us.apache.org/repos/asf/incubator-ignite/blob/2cb81f9b/modules/core/src/main/java/org/jdk8/backport/ThreadLocalRandom8.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/jdk8/backport/ThreadLocalRandom8.java b/modules/core/src/main/java/org/jdk8/backport/ThreadLocalRandom8.java
deleted file mode 100644
index 7a1493d..0000000
--- a/modules/core/src/main/java/org/jdk8/backport/ThreadLocalRandom8.java
+++ /dev/null
@@ -1,202 +0,0 @@
-/*
- * 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/
- */
-
-/*
- * The initial version of this file was copied from JSR-166:
- * http://gee.cs.oswego.edu/dl/concurrency-interest/
- */
-
-package org.jdk8.backport;
-
-import java.util.*;
-
-/**
- * A random number generator isolated to the current thread.  Like the
- * global {@link java.util.Random} generator used by the {@link
- * java.lang.Math} class, a {@code ThreadLocalRandom} is initialized
- * with an internally generated seed that may not otherwise be
- * modified. When applicable, use of {@code ThreadLocalRandom} rather
- * than shared {@code Random} objects in concurrent programs will
- * typically encounter much less overhead and contention.  Use of
- * {@code ThreadLocalRandom} is particularly appropriate when multiple
- * tasks use random numbers in parallel in thread pools.
- *
- * <p>Usages of this class should typically be of the form:
- * {@code ThreadLocalRandom.current().nextX(...)} (where
- * {@code X} is {@code Int}, {@code Long}, etc).
- * When all usages are of this form, it is never possible to
- * accidently share a {@code ThreadLocalRandom} across multiple threads.
- *
- * <p>This class also provides additional commonly used bounded random
- * generation methods.
- *
- * @since 1.7
- * @author Doug Lea
- */
-@SuppressWarnings("ALL")
-public class ThreadLocalRandom8 extends Random {
-    // same constants as Random, but must be re-declared because private
-    private static final long multiplier = 0x5DEECE66DL;
-    private static final long addend = 0xBL;
-    private static final long mask = (1L << 48) - 1;
-
-    /**
-     * The random seed. We can't use super.seed.
-     */
-    private long rnd;
-
-    /**
-     * Initialization flag to permit calls to setSeed to succeed only
-     * while executing the Random constructor.  We can't allow others
-     * since it would cause setting seed in one part of a program to
-     * unintentionally impact other usages by the thread.
-     */
-    boolean initialized;
-
-    // Padding to help avoid memory contention among seed updates in
-    // different TLRs in the common case that they are located near
-    // each other.
-    private long pad0, pad1, pad2, pad3, pad4, pad5, pad6, pad7;
-
-    /**
-     * The actual ThreadLocal
-     */
-    private static final ThreadLocal<ThreadLocalRandom8> localRandom =
-        new ThreadLocal<ThreadLocalRandom8>() {
-            protected ThreadLocalRandom8 initialValue() {
-                return new ThreadLocalRandom8();
-            }
-        };
-
-
-    /**
-     * Constructor called only by localRandom.initialValue.
-     */
-    ThreadLocalRandom8() {
-        super();
-        initialized = true;
-    }
-
-    /**
-     * Returns the current thread's {@code ThreadLocalRandom}.
-     *
-     * @return the current thread's {@code ThreadLocalRandom}
-     */
-    public static ThreadLocalRandom8 current() {
-        return localRandom.get();
-    }
-
-    /**
-     * Throws {@code UnsupportedOperationException}.  Setting seeds in
-     * this generator is not supported.
-     *
-     * @throws UnsupportedOperationException always
-     */
-    public void setSeed(long seed) {
-        if (initialized)
-            throw new UnsupportedOperationException();
-        rnd = (seed ^ multiplier) & mask;
-    }
-
-    protected int next(int bits) {
-        rnd = (rnd * multiplier + addend) & mask;
-        return (int) (rnd >>> (48-bits));
-    }
-
-    /**
-     * Returns a pseudorandom, uniformly distributed value between the
-     * given least value (inclusive) and bound (exclusive).
-     *
-     * @param least the least value returned
-     * @param bound the upper bound (exclusive)
-     * @throws IllegalArgumentException if least greater than or equal
-     * to bound
-     * @return the next value
-     */
-    public int nextInt(int least, int bound) {
-        if (least >= bound)
-            throw new IllegalArgumentException();
-        return nextInt(bound - least) + least;
-    }
-
-    /**
-     * Returns a pseudorandom, uniformly distributed value
-     * between 0 (inclusive) and the specified value (exclusive).
-     *
-     * @param n the bound on the random number to be returned.  Must be
-     *        positive.
-     * @return the next value
-     * @throws IllegalArgumentException if n is not positive
-     */
-    public long nextLong(long n) {
-        if (n <= 0)
-            throw new IllegalArgumentException("n must be positive");
-        // Divide n by two until small enough for nextInt. On each
-        // iteration (at most 31 of them but usually much less),
-        // randomly choose both whether to include high bit in result
-        // (offset) and whether to continue with the lower vs upper
-        // half (which makes a difference only if odd).
-        long offset = 0;
-        while (n >= Integer.MAX_VALUE) {
-            int bits = next(2);
-            long half = n >>> 1;
-            long nextn = ((bits & 2) == 0) ? half : n - half;
-            if ((bits & 1) == 0)
-                offset += n - nextn;
-            n = nextn;
-        }
-        return offset + nextInt((int) n);
-    }
-
-    /**
-     * Returns a pseudorandom, uniformly distributed value between the
-     * given least value (inclusive) and bound (exclusive).
-     *
-     * @param least the least value returned
-     * @param bound the upper bound (exclusive)
-     * @return the next value
-     * @throws IllegalArgumentException if least greater than or equal
-     * to bound
-     */
-    public long nextLong(long least, long bound) {
-        if (least >= bound)
-            throw new IllegalArgumentException();
-        return nextLong(bound - least) + least;
-    }
-
-    /**
-     * Returns a pseudorandom, uniformly distributed {@code double} value
-     * between 0 (inclusive) and the specified value (exclusive).
-     *
-     * @param n the bound on the random number to be returned.  Must be
-     *        positive.
-     * @return the next value
-     * @throws IllegalArgumentException if n is not positive
-     */
-    public double nextDouble(double n) {
-        if (n <= 0)
-            throw new IllegalArgumentException("n must be positive");
-        return nextDouble() * n;
-    }
-
-    /**
-     * Returns a pseudorandom, uniformly distributed value between the
-     * given least value (inclusive) and bound (exclusive).
-     *
-     * @param least the least value returned
-     * @param bound the upper bound (exclusive)
-     * @return the next value
-     * @throws IllegalArgumentException if least greater than or equal
-     * to bound
-     */
-    public double nextDouble(double least, double bound) {
-        if (least >= bound)
-            throw new IllegalArgumentException();
-        return nextDouble() * (bound - least) + least;
-    }
-
-    private static final long serialVersionUID = -5851777807851030925L;
-}


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