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package jsr166e; |
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import jsr166e.LongAdder; |
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import java.util.Arrays; |
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import java.util.Map; |
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import java.util.Set; |
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import java.util.Collection; |
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import java.util.ConcurrentModificationException; |
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import java.util.NoSuchElementException; |
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import java.util.concurrent.ConcurrentMap; |
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import java.util.concurrent.locks.LockSupport; |
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import java.io.Serializable; |
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/** |
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* <p> The table is dynamically expanded when there are too many |
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* collisions (i.e., keys that have distinct hash codes but fall into |
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* the same slot modulo the table size), with the expected average |
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* effect of maintaining roughly two bins per mapping. There may be |
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* much variance around this average as mappings are added and |
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* removed, but overall, this maintains a commonly accepted time/space |
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* tradeoff for hash tables. However, resizing this or any other kind |
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* of hash table may be a relatively slow operation. When possible, it |
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* is a good idea to provide a size estimate as an optional {@code |
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* effect of maintaining roughly two bins per mapping (corresponding |
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* to a 0.75 load factor threshold for resizing). There may be much |
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* variance around this average as mappings are added and removed, but |
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* overall, this maintains a commonly accepted time/space tradeoff for |
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* hash tables. However, resizing this or any other kind of hash |
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* table may be a relatively slow operation. When possible, it is a |
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* good idea to provide a size estimate as an optional {@code |
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* initialCapacity} constructor argument. An additional optional |
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* {@code loadFactor} constructor argument provides a further means of |
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* customizing initial table capacity by specifying the table density |
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* versions of this class, constructors may optionally specify an |
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* expected {@code concurrencyLevel} as an additional hint for |
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* internal sizing. Note that using many keys with exactly the same |
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* {@code hashCode{}} is a sure way to slow down performance of any |
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* {@code hashCode()} is a sure way to slow down performance of any |
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* hash table. |
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* |
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* <p>This class and its views and iterators implement all of the |
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* <p><em>jsr166e note: This class is a candidate replacement for |
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* java.util.concurrent.ConcurrentHashMap.<em> |
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* |
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* @since 1.8 |
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* @since 1.5 |
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* @author Doug Lea |
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* @param <K> the type of keys maintained by this map |
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* @param <V> the type of mapped values |
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private static final long serialVersionUID = 7249069246763182397L; |
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|
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/** |
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* A function computing a mapping from the given key to a value, |
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* or {@code null} if there is no mapping. This is a place-holder |
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* for an upcoming JDK8 interface. |
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* A function computing a mapping from the given key to a value. |
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* This is a place-holder for an upcoming JDK8 interface. |
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*/ |
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public static interface MappingFunction<K, V> { |
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/** |
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* Returns a value for the given key, or null if there is no |
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* mapping. If this function throws an (unchecked) exception, |
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* the exception is rethrown to its caller, and no mapping is |
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* recorded. Because this function is invoked within |
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* atomicity control, the computation should be short and |
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* simple. The most common usage is to construct a new object |
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* serving as an initial mapped value. |
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* Returns a non-null value for the given key. |
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* |
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* @param key the (non-null) key |
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* @return a value, or null if none |
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* @return a non-null value |
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*/ |
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V map(K key); |
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} |
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|
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/** |
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* A function computing a new mapping given a key and its current |
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* mapped value (or {@code null} if there is no current |
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* mapping). This is a place-holder for an upcoming JDK8 |
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* interface. |
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*/ |
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public static interface RemappingFunction<K, V> { |
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/** |
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* Returns a new value given a key and its current value. |
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* |
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* @param key the (non-null) key |
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* @param value the current value, or null if there is no mapping |
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* @return a non-null value |
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*/ |
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V remap(K key, V value); |
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} |
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|
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/* |
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* Overview: |
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* |
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* The primary design goal of this hash table is to maintain |
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* concurrent readability (typically method get(), but also |
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* iterators and related methods) while minimizing update |
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* contention. |
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* contention. Secondary goals are to keep space consumption about |
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* the same or better than java.util.HashMap, and to support high |
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* initial insertion rates on an empty table by many threads. |
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* |
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* Each key-value mapping is held in a Node. Because Node fields |
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* can contain special values, they are defined using plain Object |
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* work off Object types. And similarly, so do the internal |
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* methods of auxiliary iterator and view classes. All public |
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* generic typed methods relay in/out of these internal methods, |
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* supplying null-checks and casts as needed. |
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* supplying null-checks and casts as needed. This also allows |
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* many of the public methods to be factored into a smaller number |
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* of internal methods (although sadly not so for the five |
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* sprawling variants of put-related operations). |
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* |
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* The table is lazily initialized to a power-of-two size upon the |
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* first insertion. Each bin in the table contains a list of |
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* Nodes (most often, zero or one Node). Table accesses require |
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* volatile/atomic reads, writes, and CASes. Because there is no |
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* other way to arrange this without adding further indirections, |
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* we use intrinsics (sun.misc.Unsafe) operations. The lists of |
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* nodes within bins are always accurately traversable under |
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* volatile reads, so long as lookups check hash code and |
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* non-nullness of value before checking key equality. (All valid |
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* hash codes are nonnegative. Negative values are reserved for |
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* special forwarding nodes; see below.) |
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* Nodes (most often, the list has only zero or one Node). Table |
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* accesses require volatile/atomic reads, writes, and CASes. |
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* Because there is no other way to arrange this without adding |
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* further indirections, we use intrinsics (sun.misc.Unsafe) |
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* operations. The lists of nodes within bins are always |
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* accurately traversable under volatile reads, so long as lookups |
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* check hash code and non-nullness of value before checking key |
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* equality. |
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* |
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* We use the top two bits of Node hash fields for control |
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* purposes -- they are available anyway because of addressing |
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* constraints. As explained further below, these top bits are |
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* used as follows: |
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* 00 - Normal |
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* 01 - Locked |
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* 11 - Locked and may have a thread waiting for lock |
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* 10 - Node is a forwarding node |
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* |
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* The lower 30 bits of each Node's hash field contain a |
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* transformation (for better randomization -- method "spread") of |
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* the key's hash code, except for forwarding nodes, for which the |
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* lower bits are zero (and so always have hash field == MOVED). |
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* |
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* Insertion (via put or putIfAbsent) of the first node in an |
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* Insertion (via put or its variants) of the first node in an |
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* empty bin is performed by just CASing it to the bin. This is |
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* on average by far the most common case for put operations. |
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* Other update operations (insert, delete, and replace) require |
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* locks. We do not want to waste the space required to associate |
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* a distinct lock object with each bin, so instead use the first |
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* node of a bin list itself as a lock, using plain "synchronized" |
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* locks. These save space and we can live with block-structured |
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* lock/unlock operations. Using the first node of a list as a |
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* lock does not by itself suffice though: When a node is locked, |
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* any update must first validate that it is still the first node, |
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* and retry if not. Because new nodes are always appended to |
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* lists, once a node is first in a bin, it remains first until |
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* deleted or the bin becomes invalidated. However, operations |
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* that only conditionally update can and sometimes do inspect |
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* nodes until the point of update. This is a converse of sorts to |
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* the lazy locking technique described by Herlihy & Shavit. |
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* by far the most common case for put operations. Other update |
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* operations (insert, delete, and replace) require locks. We do |
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* not want to waste the space required to associate a distinct |
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* lock object with each bin, so instead use the first node of a |
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* bin list itself as a lock. Blocking support for these locks |
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* relies on the builtin "synchronized" monitors. However, we |
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* also need a tryLock construction, so we overlay these by using |
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* bits of the Node hash field for lock control (see above), and |
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* so normally use builtin monitors only for blocking and |
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* signalling using wait/notifyAll constructions. See |
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* Node.tryAwaitLock. |
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* |
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* Using the first node of a list as a lock does not by itself |
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* suffice though: When a node is locked, any update must first |
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* validate that it is still the first node after locking it, and |
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* retry if not. Because new nodes are always appended to lists, |
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* once a node is first in a bin, it remains first until deleted |
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* or the bin becomes invalidated (upon resizing). However, |
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* operations that only conditionally update may inspect nodes |
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* until the point of update. This is a converse of sorts to the |
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* lazy locking technique described by Herlihy & Shavit. |
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* |
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* The main disadvantage of this approach is that most update |
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* The main disadvantage of per-bin locks is that other update |
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* operations on other nodes in a bin list protected by the same |
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* lock can stall, for example when user equals() or mapping |
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* functions take a long time. However, statistically, this is |
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* that these assumptions hold unless users define exactly the |
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* same value for too many hashCodes. |
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* |
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* The table is resized when occupancy exceeds a threshold. Only |
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* a single thread performs the resize (using field "resizing", to |
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* arrange exclusion), but the table otherwise remains usable for |
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* reads and updates. Resizing proceeds by transferring bins, one |
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* by one, from the table to the next table. Upon transfer, the |
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* old table bin contains only a special forwarding node (with |
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* negative hash field) that contains the next table as its |
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* key. On encountering a forwarding node, access and update |
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* operations restart, using the new table. To ensure concurrent |
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* readability of traversals, transfers must proceed from the last |
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* bin (table.length - 1) up towards the first. Upon seeing a |
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* forwarding node, traversals (see class InternalIterator) |
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* arrange to move to the new table for the rest of the traversal |
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* without revisiting nodes. This constrains bin transfers to a |
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* particular order, and so can block indefinitely waiting for the |
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* next lock, and other threads cannot help with the transfer. |
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* However, expected stalls are infrequent enough to not warrant |
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* the additional overhead of access and iteration schemes that |
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* could admit out-of-order or concurrent bin transfers. |
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* The table is resized when occupancy exceeds an occupancy |
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* threshold (nominally, 0.75, but see below). Only a single |
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* thread performs the resize (using field "sizeCtl", to arrange |
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* exclusion), but the table otherwise remains usable for reads |
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* and updates. Resizing proceeds by transferring bins, one by |
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* one, from the table to the next table. Because we are using |
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* power-of-two expansion, the elements from each bin must either |
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* stay at same index, or move with a power of two offset. We |
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* eliminate unnecessary node creation by catching cases where old |
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* nodes can be reused because their next fields won't change. On |
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* average, only about one-sixth of them need cloning when a table |
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* doubles. The nodes they replace will be garbage collectable as |
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* soon as they are no longer referenced by any reader thread that |
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* may be in the midst of concurrently traversing table. Upon |
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* transfer, the old table bin contains only a special forwarding |
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* node (with hash field "MOVED") that contains the next table as |
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* its key. On encountering a forwarding node, access and update |
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* operations restart, using the new table. |
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* |
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* Each bin transfer requires its bin lock. However, unlike other |
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* cases, a transfer can skip a bin if it fails to acquire its |
248 |
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* lock, and revisit it later. Method rebuild maintains a buffer |
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* of TRANSFER_BUFFER_SIZE bins that have been skipped because of |
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* failure to acquire a lock, and blocks only if none are |
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* available (i.e., only very rarely). The transfer operation |
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* must also ensure that all accessible bins in both the old and |
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* new table are usable by any traversal. When there are no lock |
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* acquisition failures, this is arranged simply by proceeding |
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* from the last bin (table.length - 1) up towards the first. |
256 |
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* Upon seeing a forwarding node, traversals (see class |
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* InternalIterator) arrange to move to the new table without |
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* revisiting nodes. However, when any node is skipped during a |
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* transfer, all earlier table bins may have become visible, so |
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* are initialized with a reverse-forwarding node back to the old |
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* table until the new ones are established. (This sometimes |
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* requires transiently locking a forwarding node, which is |
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* possible under the above encoding.) These more expensive |
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* mechanics trigger only when necessary. |
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* |
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* This traversal scheme also applies to partial traversals of |
266 |
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* The traversal scheme also applies to partial traversals of |
267 |
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* ranges of bins (via an alternate InternalIterator constructor) |
268 |
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* to support partitioned aggregate operations (that are not |
269 |
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* otherwise implemented yet). Also, read-only operations give up |
274 |
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* Lazy table initialization minimizes footprint until first use, |
275 |
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* and also avoids resizings when the first operation is from a |
276 |
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* putAll, constructor with map argument, or deserialization. |
277 |
< |
* These cases attempt to override the targetCapacity used in |
278 |
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* growTable. These harmlessly fail to take effect in cases of |
223 |
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* races with other ongoing resizings. Uses of the threshold and |
224 |
< |
* targetCapacity during attempted initializations or resizings |
225 |
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* are racy but fall back on checks to preserve correctness. |
277 |
> |
* These cases attempt to override the initial capacity settings, |
278 |
> |
* but harmlessly fail to take effect in cases of races. |
279 |
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* |
280 |
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* The element count is maintained using a LongAdder, which avoids |
281 |
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* contention on updates but can encounter cache thrashing if read |
282 |
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* too frequently during concurrent access. To avoid reading so |
283 |
< |
* often, resizing is normally attempted only upon adding to a bin |
284 |
< |
* already holding two or more nodes. Under uniform hash |
285 |
< |
* distributions, the probability of this occurring at threshold |
286 |
< |
* is around 13%, meaning that only about 1 in 8 puts check |
287 |
< |
* threshold (and after resizing, many fewer do so). But this |
288 |
< |
* approximation has high variance for small table sizes, so we |
289 |
< |
* check on any collision for sizes <= 64. Further, to increase |
290 |
< |
* the probability that a resize occurs soon enough, we offset the |
291 |
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* threshold (see THRESHOLD_OFFSET) by the expected number of puts |
292 |
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* between checks. |
283 |
> |
* often, resizing is attempted either when a bin lock is |
284 |
> |
* contended, or upon adding to a bin already holding two or more |
285 |
> |
* nodes (checked before adding in the xIfAbsent methods, after |
286 |
> |
* adding in others). Under uniform hash distributions, the |
287 |
> |
* probability of this occurring at threshold is around 13%, |
288 |
> |
* meaning that only about 1 in 8 puts check threshold (and after |
289 |
> |
* resizing, many fewer do so). But this approximation has high |
290 |
> |
* variance for small table sizes, so we check on any collision |
291 |
> |
* for sizes <= 64. The bulk putAll operation further reduces |
292 |
> |
* contention by only committing count updates upon these size |
293 |
> |
* checks. |
294 |
|
* |
295 |
|
* Maintaining API and serialization compatibility with previous |
296 |
|
* versions of this class introduces several oddities. Mainly: We |
297 |
|
* leave untouched but unused constructor arguments refering to |
298 |
< |
* concurrencyLevel. We also declare an unused "Segment" class |
299 |
< |
* that is instantiated in minimal form only when serializing. |
298 |
> |
* concurrencyLevel. We accept a loadFactor constructor argument, |
299 |
> |
* but apply it only to initial table capacity (which is the only |
300 |
> |
* time that we can guarantee to honor it.) We also declare an |
301 |
> |
* unused "Segment" class that is instantiated in minimal form |
302 |
> |
* only when serializing. |
303 |
|
*/ |
304 |
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|
305 |
|
/* ---------------- Constants -------------- */ |
307 |
|
/** |
308 |
|
* The largest possible table capacity. This value must be |
309 |
|
* exactly 1<<30 to stay within Java array allocation and indexing |
310 |
< |
* bounds for power of two table sizes. |
310 |
> |
* bounds for power of two table sizes, and is further required |
311 |
> |
* because the top two bits of 32bit hash fields are used for |
312 |
> |
* control purposes. |
313 |
|
*/ |
314 |
|
private static final int MAXIMUM_CAPACITY = 1 << 30; |
315 |
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|
320 |
|
private static final int DEFAULT_CAPACITY = 16; |
321 |
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|
322 |
|
/** |
323 |
+ |
* The largest possible (non-power of two) array size. |
324 |
+ |
* Needed by toArray and related methods. |
325 |
+ |
*/ |
326 |
+ |
static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; |
327 |
+ |
|
328 |
+ |
/** |
329 |
+ |
* The default concurrency level for this table. Unused but |
330 |
+ |
* defined for compatibility with previous versions of this class. |
331 |
+ |
*/ |
332 |
+ |
private static final int DEFAULT_CONCURRENCY_LEVEL = 16; |
333 |
+ |
|
334 |
+ |
/** |
335 |
|
* The load factor for this table. Overrides of this value in |
336 |
|
* constructors affect only the initial table capacity. The |
337 |
< |
* actual floating point value isn't normally used, because it is |
338 |
< |
* simpler to rely on the expression {@code n - (n >>> 2)} for the |
339 |
< |
* associated resizing threshold. |
337 |
> |
* actual floating point value isn't normally used -- it is |
338 |
> |
* simpler to use expressions such as {@code n - (n >>> 2)} for |
339 |
> |
* the associated resizing threshold. |
340 |
|
*/ |
341 |
|
private static final float LOAD_FACTOR = 0.75f; |
342 |
|
|
343 |
|
/** |
344 |
< |
* The count value to offset thresholds to compensate for checking |
345 |
< |
* for the need to resize only when inserting into bins with two |
346 |
< |
* or more elements. See above for explanation. |
344 |
> |
* The buffer size for skipped bins during transfers. The |
345 |
> |
* value is arbitrary but should be large enough to avoid |
346 |
> |
* most locking stalls during resizes. |
347 |
> |
*/ |
348 |
> |
private static final int TRANSFER_BUFFER_SIZE = 32; |
349 |
> |
|
350 |
> |
/* |
351 |
> |
* Encodings for special uses of Node hash fields. See above for |
352 |
> |
* explanation. |
353 |
> |
*/ |
354 |
> |
static final int MOVED = 0x80000000; // hash field for forwarding nodes |
355 |
> |
static final int LOCKED = 0x40000000; // set/tested only as a bit |
356 |
> |
static final int WAITING = 0xc0000000; // both bits set/tested together |
357 |
> |
static final int HASH_BITS = 0x3fffffff; // usable bits of normal node hash |
358 |
> |
|
359 |
> |
/* ---------------- Fields -------------- */ |
360 |
> |
|
361 |
> |
/** |
362 |
> |
* The array of bins. Lazily initialized upon first insertion. |
363 |
> |
* Size is always a power of two. Accessed directly by iterators. |
364 |
> |
*/ |
365 |
> |
transient volatile Node[] table; |
366 |
> |
|
367 |
> |
/** |
368 |
> |
* The counter maintaining number of elements. |
369 |
|
*/ |
370 |
< |
private static final int THRESHOLD_OFFSET = 8; |
370 |
> |
private transient final LongAdder counter; |
371 |
|
|
372 |
|
/** |
373 |
< |
* The default concurrency level for this table. Unused except as |
374 |
< |
* a sizing hint, but defined for compatibility with previous |
375 |
< |
* versions of this class. |
373 |
> |
* Table initialization and resizing control. When negative, the |
374 |
> |
* table is being initialized or resized. Otherwise, when table is |
375 |
> |
* null, holds the initial table size to use upon creation, or 0 |
376 |
> |
* for default. After initialization, holds the next element count |
377 |
> |
* value upon which to resize the table. |
378 |
|
*/ |
379 |
< |
private static final int DEFAULT_CONCURRENCY_LEVEL = 16; |
379 |
> |
private transient volatile int sizeCtl; |
380 |
> |
|
381 |
> |
// views |
382 |
> |
private transient KeySet<K,V> keySet; |
383 |
> |
private transient Values<K,V> values; |
384 |
> |
private transient EntrySet<K,V> entrySet; |
385 |
> |
|
386 |
> |
/** For serialization compatibility. Null unless serialized; see below */ |
387 |
> |
private Segment<K,V>[] segments; |
388 |
|
|
389 |
|
/* ---------------- Nodes -------------- */ |
390 |
|
|
391 |
|
/** |
392 |
|
* Key-value entry. Note that this is never exported out as a |
393 |
< |
* user-visible Map.Entry. Nodes with a negative hash field are |
394 |
< |
* special, and do not contain user keys or values. Otherwise, |
395 |
< |
* keys are never null, and null val fields indicate that a node |
396 |
< |
* is in the process of being deleted or created. For purposes of |
397 |
< |
* read-only, access, a key may be read before a val, but can only |
398 |
< |
* be used after checking val. (For an update operation, when a |
399 |
< |
* lock is held on a node, order doesn't matter.) |
393 |
> |
* user-visible Map.Entry (see WriteThroughEntry and SnapshotEntry |
394 |
> |
* below). Nodes with a hash field of MOVED are special, and do |
395 |
> |
* not contain user keys or values. Otherwise, keys are never |
396 |
> |
* null, and null val fields indicate that a node is in the |
397 |
> |
* process of being deleted or created. For purposes of read-only |
398 |
> |
* access, a key may be read before a val, but can only be used |
399 |
> |
* after checking val to be non-null. |
400 |
|
*/ |
401 |
|
static final class Node { |
402 |
< |
final int hash; |
402 |
> |
volatile int hash; |
403 |
|
final Object key; |
404 |
|
volatile Object val; |
405 |
|
volatile Node next; |
410 |
|
this.val = val; |
411 |
|
this.next = next; |
412 |
|
} |
310 |
– |
} |
413 |
|
|
414 |
< |
/** |
415 |
< |
* Sign bit of node hash value indicating to use table in node.key. |
416 |
< |
*/ |
417 |
< |
private static final int SIGN_BIT = 0x80000000; |
316 |
< |
|
317 |
< |
/* ---------------- Fields -------------- */ |
414 |
> |
/** CompareAndSet the hash field */ |
415 |
> |
final boolean casHash(int cmp, int val) { |
416 |
> |
return UNSAFE.compareAndSwapInt(this, hashOffset, cmp, val); |
417 |
> |
} |
418 |
|
|
419 |
< |
/** |
420 |
< |
* The array of bins. Lazily initialized upon first insertion. |
421 |
< |
* Size is always a power of two. Accessed directly by iterators. |
322 |
< |
*/ |
323 |
< |
transient volatile Node[] table; |
419 |
> |
/** The number of spins before blocking for a lock */ |
420 |
> |
static final int MAX_SPINS = |
421 |
> |
Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1; |
422 |
|
|
423 |
< |
/** The counter maintaining number of elements. */ |
424 |
< |
private transient final LongAdder counter; |
425 |
< |
/** Nonzero when table is being initialized or resized. Updated via CAS. */ |
426 |
< |
private transient volatile int resizing; |
427 |
< |
/** The next element count value upon which to resize the table. */ |
428 |
< |
private transient int threshold; |
429 |
< |
/** The target capacity; volatile to cover initialization races. */ |
430 |
< |
private transient volatile int targetCapacity; |
423 |
> |
/** |
424 |
> |
* Spins a while if LOCKED bit set and this node is the first |
425 |
> |
* of its bin, and then sets WAITING bits on hash field and |
426 |
> |
* blocks (once) if they are still set. It is OK for this |
427 |
> |
* method to return even if lock is not available upon exit, |
428 |
> |
* which enables these simple single-wait mechanics. |
429 |
> |
* |
430 |
> |
* The corresponding signalling operation is performed within |
431 |
> |
* callers: Upon detecting that WAITING has been set when |
432 |
> |
* unlocking lock (via a failed CAS from non-waiting LOCKED |
433 |
> |
* state), unlockers acquire the sync lock and perform a |
434 |
> |
* notifyAll. |
435 |
> |
*/ |
436 |
> |
final void tryAwaitLock(Node[] tab, int i) { |
437 |
> |
if (tab != null && i >= 0 && i < tab.length) { // bounds check |
438 |
> |
int spins = MAX_SPINS, h; |
439 |
> |
while (tabAt(tab, i) == this && ((h = hash) & LOCKED) != 0) { |
440 |
> |
if (spins >= 0) { |
441 |
> |
if (--spins == MAX_SPINS >>> 1) |
442 |
> |
Thread.yield(); // heuristically yield mid-way |
443 |
> |
} |
444 |
> |
else if (casHash(h, h | WAITING)) { |
445 |
> |
synchronized (this) { |
446 |
> |
if (tabAt(tab, i) == this && |
447 |
> |
(hash & WAITING) == WAITING) { |
448 |
> |
try { |
449 |
> |
wait(); |
450 |
> |
} catch (InterruptedException ie) { |
451 |
> |
Thread.currentThread().interrupt(); |
452 |
> |
} |
453 |
> |
} |
454 |
> |
else |
455 |
> |
notifyAll(); // possibly won race vs signaller |
456 |
> |
} |
457 |
> |
break; |
458 |
> |
} |
459 |
> |
} |
460 |
> |
} |
461 |
> |
} |
462 |
|
|
463 |
< |
// views |
464 |
< |
private transient KeySet<K,V> keySet; |
465 |
< |
private transient Values<K,V> values; |
337 |
< |
private transient EntrySet<K,V> entrySet; |
463 |
> |
// Unsafe mechanics for casHash |
464 |
> |
private static final sun.misc.Unsafe UNSAFE; |
465 |
> |
private static final long hashOffset; |
466 |
|
|
467 |
< |
/** For serialization compatibility. Null unless serialized; see below */ |
468 |
< |
private Segment<K,V>[] segments; |
467 |
> |
static { |
468 |
> |
try { |
469 |
> |
UNSAFE = getUnsafe(); |
470 |
> |
Class<?> k = Node.class; |
471 |
> |
hashOffset = UNSAFE.objectFieldOffset |
472 |
> |
(k.getDeclaredField("hash")); |
473 |
> |
} catch (Exception e) { |
474 |
> |
throw new Error(e); |
475 |
> |
} |
476 |
> |
} |
477 |
> |
} |
478 |
|
|
479 |
|
/* ---------------- Table element access -------------- */ |
480 |
|
|
502 |
|
UNSAFE.putObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE, v); |
503 |
|
} |
504 |
|
|
368 |
– |
/* ----------------Table Initialization and Resizing -------------- */ |
369 |
– |
|
370 |
– |
/** |
371 |
– |
* Returns a power of two table size for the given desired capacity. |
372 |
– |
* See Hackers Delight, sec 3.2 |
373 |
– |
*/ |
374 |
– |
private static final int tableSizeFor(int c) { |
375 |
– |
int n = c - 1; |
376 |
– |
n |= n >>> 1; |
377 |
– |
n |= n >>> 2; |
378 |
– |
n |= n >>> 4; |
379 |
– |
n |= n >>> 8; |
380 |
– |
n |= n >>> 16; |
381 |
– |
return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1; |
382 |
– |
} |
383 |
– |
|
384 |
– |
/** |
385 |
– |
* If not already resizing, initializes or creates next table and |
386 |
– |
* transfers bins. Initial table size uses the capacity recorded |
387 |
– |
* in targetCapacity. Rechecks occupancy after a transfer to see |
388 |
– |
* if another resize is already needed because resizings are |
389 |
– |
* lagging additions. |
390 |
– |
* |
391 |
– |
* @return current table |
392 |
– |
*/ |
393 |
– |
private final Node[] growTable() { |
394 |
– |
if (resizing == 0 && |
395 |
– |
UNSAFE.compareAndSwapInt(this, resizingOffset, 0, 1)) { |
396 |
– |
try { |
397 |
– |
for (;;) { |
398 |
– |
Node[] tab = table; |
399 |
– |
int n, c, m; |
400 |
– |
if (tab == null) |
401 |
– |
n = (c = targetCapacity) > 0 ? c : DEFAULT_CAPACITY; |
402 |
– |
else if ((m = tab.length) < MAXIMUM_CAPACITY && |
403 |
– |
counter.sum() >= (long)threshold) |
404 |
– |
n = m << 1; |
405 |
– |
else |
406 |
– |
break; |
407 |
– |
threshold = n - (n >>> 2) - THRESHOLD_OFFSET; |
408 |
– |
Node[] nextTab = new Node[n]; |
409 |
– |
if (tab != null) |
410 |
– |
transfer(tab, nextTab, |
411 |
– |
new Node(SIGN_BIT, nextTab, null, null)); |
412 |
– |
table = nextTab; |
413 |
– |
if (tab == null) |
414 |
– |
break; |
415 |
– |
} |
416 |
– |
} finally { |
417 |
– |
resizing = 0; |
418 |
– |
} |
419 |
– |
} |
420 |
– |
else if (table == null) |
421 |
– |
Thread.yield(); // lost initialization race; just spin |
422 |
– |
return table; |
423 |
– |
} |
424 |
– |
|
425 |
– |
/** |
426 |
– |
* Reclassifies nodes in each bin to new table. Because we are |
427 |
– |
* using power-of-two expansion, the elements from each bin must |
428 |
– |
* either stay at same index, or move with a power of two |
429 |
– |
* offset. We eliminate unnecessary node creation by catching |
430 |
– |
* cases where old nodes can be reused because their next fields |
431 |
– |
* won't change. Statistically, only about one-sixth of them need |
432 |
– |
* cloning when a table doubles. The nodes they replace will be |
433 |
– |
* garbage collectable as soon as they are no longer referenced by |
434 |
– |
* any reader thread that may be in the midst of concurrently |
435 |
– |
* traversing table. |
436 |
– |
* |
437 |
– |
* Transfers are done from the bottom up to preserve iterator |
438 |
– |
* traversability. On each step, the old bin is locked, |
439 |
– |
* moved/copied, and then replaced with a forwarding node. |
440 |
– |
*/ |
441 |
– |
private static final void transfer(Node[] tab, Node[] nextTab, Node fwd) { |
442 |
– |
int n = tab.length; |
443 |
– |
Node ignore = nextTab[n + n - 1]; // force bounds check |
444 |
– |
for (int i = n - 1; i >= 0; --i) { |
445 |
– |
for (Node e;;) { |
446 |
– |
if ((e = tabAt(tab, i)) != null) { |
447 |
– |
boolean validated = false; |
448 |
– |
synchronized (e) { |
449 |
– |
if (tabAt(tab, i) == e) { |
450 |
– |
validated = true; |
451 |
– |
Node lo = null, hi = null, lastRun = e; |
452 |
– |
int runBit = e.hash & n; |
453 |
– |
for (Node p = e.next; p != null; p = p.next) { |
454 |
– |
int b = p.hash & n; |
455 |
– |
if (b != runBit) { |
456 |
– |
runBit = b; |
457 |
– |
lastRun = p; |
458 |
– |
} |
459 |
– |
} |
460 |
– |
if (runBit == 0) |
461 |
– |
lo = lastRun; |
462 |
– |
else |
463 |
– |
hi = lastRun; |
464 |
– |
for (Node p = e; p != lastRun; p = p.next) { |
465 |
– |
int ph = p.hash; |
466 |
– |
Object pk = p.key, pv = p.val; |
467 |
– |
if ((ph & n) == 0) |
468 |
– |
lo = new Node(ph, pk, pv, lo); |
469 |
– |
else |
470 |
– |
hi = new Node(ph, pk, pv, hi); |
471 |
– |
} |
472 |
– |
setTabAt(nextTab, i, lo); |
473 |
– |
setTabAt(nextTab, i + n, hi); |
474 |
– |
setTabAt(tab, i, fwd); |
475 |
– |
} |
476 |
– |
} |
477 |
– |
if (validated) |
478 |
– |
break; |
479 |
– |
} |
480 |
– |
else if (casTabAt(tab, i, e, fwd)) |
481 |
– |
break; |
482 |
– |
} |
483 |
– |
} |
484 |
– |
} |
485 |
– |
|
505 |
|
/* ---------------- Internal access and update methods -------------- */ |
506 |
|
|
507 |
|
/** |
508 |
|
* Applies a supplemental hash function to a given hashCode, which |
509 |
|
* defends against poor quality hash functions. The result must |
510 |
< |
* be non-negative, and for reasonable performance must have good |
511 |
< |
* avalanche properties; i.e., that each bit of the argument |
512 |
< |
* affects each bit (except sign bit) of the result. |
510 |
> |
* be have the top 2 bits clear. For reasonable performance, this |
511 |
> |
* function must have good avalanche properties; i.e., that each |
512 |
> |
* bit of the argument affects each bit of the result. (Although |
513 |
> |
* we don't care about the unused top 2 bits.) |
514 |
|
*/ |
515 |
|
private static final int spread(int h) { |
516 |
|
// Apply base step of MurmurHash; see http://code.google.com/p/smhasher/ |
517 |
+ |
// Despite two multiplies, this is often faster than others |
518 |
+ |
// with comparable bit-spread properties. |
519 |
|
h ^= h >>> 16; |
520 |
|
h *= 0x85ebca6b; |
521 |
|
h ^= h >>> 13; |
522 |
|
h *= 0xc2b2ae35; |
523 |
< |
return (h >>> 16) ^ (h & 0x7fffffff); // mask out sign bit |
523 |
> |
return ((h >>> 16) ^ h) & HASH_BITS; // mask out top bits |
524 |
|
} |
525 |
|
|
526 |
|
/** Implementation for get and containsKey */ |
527 |
|
private final Object internalGet(Object k) { |
528 |
|
int h = spread(k.hashCode()); |
529 |
|
retry: for (Node[] tab = table; tab != null;) { |
530 |
< |
Node e; Object ek, ev; int eh; // locals to read fields once |
530 |
> |
Node e; Object ek, ev; int eh; // locals to read fields once |
531 |
|
for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) { |
532 |
< |
if ((eh = e.hash) == h) { |
533 |
< |
if ((ev = e.val) != null && |
512 |
< |
((ek = e.key) == k || k.equals(ek))) |
513 |
< |
return ev; |
514 |
< |
} |
515 |
< |
else if (eh < 0) { // sign bit set |
516 |
< |
tab = (Node[])e.key; // bin was moved during resize |
532 |
> |
if ((eh = e.hash) == MOVED) { |
533 |
> |
tab = (Node[])e.key; // restart with new table |
534 |
|
continue retry; |
535 |
|
} |
536 |
+ |
if ((eh & HASH_BITS) == h && (ev = e.val) != null && |
537 |
+ |
((ek = e.key) == k || k.equals(ek))) |
538 |
+ |
return ev; |
539 |
|
} |
540 |
|
break; |
541 |
|
} |
542 |
|
return null; |
543 |
|
} |
544 |
|
|
545 |
< |
/** Implementation for put and putIfAbsent */ |
546 |
< |
private final Object internalPut(Object k, Object v, boolean replace) { |
545 |
> |
/** |
546 |
> |
* Implementation for the four public remove/replace methods: |
547 |
> |
* Replaces node value with v, conditional upon match of cv if |
548 |
> |
* non-null. If resulting value is null, delete. |
549 |
> |
*/ |
550 |
> |
private final Object internalReplace(Object k, Object v, Object cv) { |
551 |
> |
int h = spread(k.hashCode()); |
552 |
> |
Object oldVal = null; |
553 |
> |
for (Node[] tab = table;;) { |
554 |
> |
Node f; int i, fh; |
555 |
> |
if (tab == null || |
556 |
> |
(f = tabAt(tab, i = (tab.length - 1) & h)) == null) |
557 |
> |
break; |
558 |
> |
else if ((fh = f.hash) == MOVED) |
559 |
> |
tab = (Node[])f.key; |
560 |
> |
else if ((fh & HASH_BITS) != h && f.next == null) // precheck |
561 |
> |
break; // rules out possible existence |
562 |
> |
else if ((fh & LOCKED) != 0) { |
563 |
> |
checkForResize(); // try resizing if can't get lock |
564 |
> |
f.tryAwaitLock(tab, i); |
565 |
> |
} |
566 |
> |
else if (f.casHash(fh, fh | LOCKED)) { |
567 |
> |
boolean validated = false; |
568 |
> |
boolean deleted = false; |
569 |
> |
try { |
570 |
> |
if (tabAt(tab, i) == f) { |
571 |
> |
validated = true; |
572 |
> |
for (Node e = f, pred = null;;) { |
573 |
> |
Object ek, ev; |
574 |
> |
if ((e.hash & HASH_BITS) == h && |
575 |
> |
((ev = e.val) != null) && |
576 |
> |
((ek = e.key) == k || k.equals(ek))) { |
577 |
> |
if (cv == null || cv == ev || cv.equals(ev)) { |
578 |
> |
oldVal = ev; |
579 |
> |
if ((e.val = v) == null) { |
580 |
> |
deleted = true; |
581 |
> |
Node en = e.next; |
582 |
> |
if (pred != null) |
583 |
> |
pred.next = en; |
584 |
> |
else |
585 |
> |
setTabAt(tab, i, en); |
586 |
> |
} |
587 |
> |
} |
588 |
> |
break; |
589 |
> |
} |
590 |
> |
pred = e; |
591 |
> |
if ((e = e.next) == null) |
592 |
> |
break; |
593 |
> |
} |
594 |
> |
} |
595 |
> |
} finally { |
596 |
> |
if (!f.casHash(fh | LOCKED, fh)) { |
597 |
> |
f.hash = fh; |
598 |
> |
synchronized (f) { f.notifyAll(); }; |
599 |
> |
} |
600 |
> |
} |
601 |
> |
if (validated) { |
602 |
> |
if (deleted) |
603 |
> |
counter.add(-1L); |
604 |
> |
break; |
605 |
> |
} |
606 |
> |
} |
607 |
> |
} |
608 |
> |
return oldVal; |
609 |
> |
} |
610 |
> |
|
611 |
> |
/* |
612 |
> |
* Internal versions of the five insertion methods, each a |
613 |
> |
* little more complicated than the last. All have |
614 |
> |
* the same basic structure as the first (internalPut): |
615 |
> |
* 1. If table uninitialized, create |
616 |
> |
* 2. If bin empty, try to CAS new node |
617 |
> |
* 3. If bin stale, use new table |
618 |
> |
* 4. Lock and validate; if valid, scan and add or update |
619 |
> |
* |
620 |
> |
* The others interweave other checks and/or alternative actions: |
621 |
> |
* * Plain put checks for and performs resize after insertion. |
622 |
> |
* * putIfAbsent prescans for mapping without lock (and fails to add |
623 |
> |
* if present), which also makes pre-emptive resize checks worthwhile. |
624 |
> |
* * computeIfAbsent extends form used in putIfAbsent with additional |
625 |
> |
* mechanics to deal with, calls, potential exceptions and null |
626 |
> |
* returns from function call. |
627 |
> |
* * compute uses the same function-call mechanics, but without |
628 |
> |
* the prescans |
629 |
> |
* * putAll attempts to pre-allocate enough table space |
630 |
> |
* and more lazily performs count updates and checks. |
631 |
> |
* |
632 |
> |
* Someday when details settle down a bit more, it might be worth |
633 |
> |
* some factoring to reduce sprawl. |
634 |
> |
*/ |
635 |
> |
|
636 |
> |
/** Implementation for put */ |
637 |
> |
private final Object internalPut(Object k, Object v) { |
638 |
|
int h = spread(k.hashCode()); |
639 |
< |
Object oldVal = null; // previous value or null if none |
639 |
> |
boolean checkSize = false; |
640 |
|
for (Node[] tab = table;;) { |
641 |
< |
Node e; int i; Object ek, ev; |
641 |
> |
int i; Node f; int fh; |
642 |
|
if (tab == null) |
643 |
< |
tab = growTable(); |
644 |
< |
else if ((e = tabAt(tab, i = (tab.length - 1) & h)) == null) { |
643 |
> |
tab = initTable(); |
644 |
> |
else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { |
645 |
|
if (casTabAt(tab, i, null, new Node(h, k, v, null))) |
646 |
|
break; // no lock when adding to empty bin |
647 |
|
} |
648 |
< |
else if (e.hash < 0) // resized -- restart with new table |
649 |
< |
tab = (Node[])e.key; |
650 |
< |
else if (!replace && e.hash == h && (ev = e.val) != null && |
651 |
< |
((ek = e.key) == k || k.equals(ek))) { |
652 |
< |
if (tabAt(tab, i) == e) { // inspect and validate 1st node |
542 |
< |
oldVal = ev; // without lock for putIfAbsent |
543 |
< |
break; |
544 |
< |
} |
648 |
> |
else if ((fh = f.hash) == MOVED) |
649 |
> |
tab = (Node[])f.key; |
650 |
> |
else if ((fh & LOCKED) != 0) { |
651 |
> |
checkForResize(); |
652 |
> |
f.tryAwaitLock(tab, i); |
653 |
|
} |
654 |
< |
else { |
654 |
> |
else if (f.casHash(fh, fh | LOCKED)) { |
655 |
> |
Object oldVal = null; |
656 |
|
boolean validated = false; |
657 |
< |
boolean checkSize = false; |
658 |
< |
synchronized (e) { // lock the 1st node of bin list |
550 |
< |
if (tabAt(tab, i) == e) { |
657 |
> |
try { // needed in case equals() throws |
658 |
> |
if (tabAt(tab, i) == f) { |
659 |
|
validated = true; // retry if 1st already deleted |
660 |
< |
for (Node first = e;;) { |
661 |
< |
if (e.hash == h && |
662 |
< |
((ek = e.key) == k || k.equals(ek)) && |
663 |
< |
(ev = e.val) != null) { |
660 |
> |
for (Node e = f;;) { |
661 |
> |
Object ek, ev; |
662 |
> |
if ((e.hash & HASH_BITS) == h && |
663 |
> |
(ev = e.val) != null && |
664 |
> |
((ek = e.key) == k || k.equals(ek))) { |
665 |
|
oldVal = ev; |
666 |
< |
if (replace) |
558 |
< |
e.val = v; |
666 |
> |
e.val = v; |
667 |
|
break; |
668 |
|
} |
669 |
|
Node last = e; |
670 |
|
if ((e = e.next) == null) { |
671 |
|
last.next = new Node(h, k, v, null); |
672 |
< |
if (last != first || tab.length <= 64) |
672 |
> |
if (last != f || tab.length <= 64) |
673 |
|
checkSize = true; |
674 |
|
break; |
675 |
|
} |
676 |
|
} |
677 |
|
} |
678 |
+ |
} finally { // unlock and signal if needed |
679 |
+ |
if (!f.casHash(fh | LOCKED, fh)) { |
680 |
+ |
f.hash = fh; |
681 |
+ |
synchronized (f) { f.notifyAll(); }; |
682 |
+ |
} |
683 |
|
} |
684 |
|
if (validated) { |
685 |
< |
if (checkSize && tab.length < MAXIMUM_CAPACITY && |
686 |
< |
resizing == 0 && counter.sum() >= (long)threshold) |
574 |
< |
growTable(); |
685 |
> |
if (oldVal != null) |
686 |
> |
return oldVal; |
687 |
|
break; |
688 |
|
} |
689 |
|
} |
690 |
|
} |
691 |
< |
if (oldVal == null) |
692 |
< |
counter.increment(); // update counter outside of locks |
693 |
< |
return oldVal; |
691 |
> |
counter.add(1L); |
692 |
> |
if (checkSize) |
693 |
> |
checkForResize(); |
694 |
> |
return null; |
695 |
|
} |
696 |
|
|
697 |
< |
/** |
698 |
< |
* Implementation for the four public remove/replace methods: |
586 |
< |
* Replaces node value with v, conditional upon match of cv if |
587 |
< |
* non-null. If resulting value is null, delete. |
588 |
< |
*/ |
589 |
< |
private final Object internalReplace(Object k, Object v, Object cv) { |
697 |
> |
/** Implementation for putIfAbsent */ |
698 |
> |
private final Object internalPutIfAbsent(Object k, Object v) { |
699 |
|
int h = spread(k.hashCode()); |
700 |
|
for (Node[] tab = table;;) { |
701 |
< |
Node e; int i; |
702 |
< |
if (tab == null || |
703 |
< |
(e = tabAt(tab, i = (tab.length - 1) & h)) == null) |
704 |
< |
return null; |
705 |
< |
else if (e.hash < 0) |
706 |
< |
tab = (Node[])e.key; |
701 |
> |
int i; Node f; int fh; Object fk, fv; |
702 |
> |
if (tab == null) |
703 |
> |
tab = initTable(); |
704 |
> |
else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { |
705 |
> |
if (casTabAt(tab, i, null, new Node(h, k, v, null))) |
706 |
> |
break; |
707 |
> |
} |
708 |
> |
else if ((fh = f.hash) == MOVED) |
709 |
> |
tab = (Node[])f.key; |
710 |
> |
else if ((fh & HASH_BITS) == h && (fv = f.val) != null && |
711 |
> |
((fk = f.key) == k || k.equals(fk))) |
712 |
> |
return fv; |
713 |
|
else { |
714 |
< |
Object oldVal = null; |
715 |
< |
boolean validated = false; |
716 |
< |
boolean deleted = false; |
717 |
< |
synchronized (e) { |
718 |
< |
if (tabAt(tab, i) == e) { |
719 |
< |
validated = true; |
720 |
< |
Node pred = null; |
721 |
< |
do { |
722 |
< |
Object ek, ev; |
723 |
< |
if (e.hash == h && |
724 |
< |
((ek = e.key) == k || k.equals(ek)) && |
725 |
< |
((ev = e.val) != null)) { |
726 |
< |
if (cv == null || cv == ev || cv.equals(ev)) { |
714 |
> |
Node g = f.next; |
715 |
> |
if (g != null) { // at least 2 nodes -- search and maybe resize |
716 |
> |
for (Node e = g;;) { |
717 |
> |
Object ek, ev; |
718 |
> |
if ((e.hash & HASH_BITS) == h && (ev = e.val) != null && |
719 |
> |
((ek = e.key) == k || k.equals(ek))) |
720 |
> |
return ev; |
721 |
> |
if ((e = e.next) == null) { |
722 |
> |
checkForResize(); |
723 |
> |
break; |
724 |
> |
} |
725 |
> |
} |
726 |
> |
} |
727 |
> |
if (((fh = f.hash) & LOCKED) != 0) { |
728 |
> |
checkForResize(); |
729 |
> |
f.tryAwaitLock(tab, i); |
730 |
> |
} |
731 |
> |
else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) { |
732 |
> |
Object oldVal = null; |
733 |
> |
boolean validated = false; |
734 |
> |
try { |
735 |
> |
if (tabAt(tab, i) == f) { |
736 |
> |
validated = true; |
737 |
> |
for (Node e = f;;) { |
738 |
> |
Object ek, ev; |
739 |
> |
if ((e.hash & HASH_BITS) == h && |
740 |
> |
(ev = e.val) != null && |
741 |
> |
((ek = e.key) == k || k.equals(ek))) { |
742 |
|
oldVal = ev; |
743 |
< |
if ((e.val = v) == null) { |
744 |
< |
deleted = true; |
745 |
< |
Node en = e.next; |
746 |
< |
if (pred != null) |
747 |
< |
pred.next = en; |
748 |
< |
else |
619 |
< |
setTabAt(tab, i, en); |
620 |
< |
} |
743 |
> |
break; |
744 |
> |
} |
745 |
> |
Node last = e; |
746 |
> |
if ((e = e.next) == null) { |
747 |
> |
last.next = new Node(h, k, v, null); |
748 |
> |
break; |
749 |
|
} |
622 |
– |
break; |
750 |
|
} |
751 |
< |
} while ((e = (pred = e).next) != null); |
751 |
> |
} |
752 |
> |
} finally { |
753 |
> |
if (!f.casHash(fh | LOCKED, fh)) { |
754 |
> |
f.hash = fh; |
755 |
> |
synchronized (f) { f.notifyAll(); }; |
756 |
> |
} |
757 |
> |
} |
758 |
> |
if (validated) { |
759 |
> |
if (oldVal != null) |
760 |
> |
return oldVal; |
761 |
> |
break; |
762 |
|
} |
763 |
|
} |
764 |
< |
if (validated) { |
765 |
< |
if (deleted) |
766 |
< |
counter.decrement(); |
767 |
< |
return oldVal; |
764 |
> |
} |
765 |
> |
} |
766 |
> |
counter.add(1L); |
767 |
> |
return null; |
768 |
> |
} |
769 |
> |
|
770 |
> |
/** Implementation for computeIfAbsent */ |
771 |
> |
private final Object internalComputeIfAbsent(K k, |
772 |
> |
MappingFunction<? super K, ?> mf) { |
773 |
> |
int h = spread(k.hashCode()); |
774 |
> |
Object val = null; |
775 |
> |
for (Node[] tab = table;;) { |
776 |
> |
Node f; int i, fh; Object fk, fv; |
777 |
> |
if (tab == null) |
778 |
> |
tab = initTable(); |
779 |
> |
else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { |
780 |
> |
Node node = new Node(fh = h | LOCKED, k, null, null); |
781 |
> |
boolean validated = false; |
782 |
> |
if (casTabAt(tab, i, null, node)) { |
783 |
> |
validated = true; |
784 |
> |
try { |
785 |
> |
if ((val = mf.map(k)) != null) |
786 |
> |
node.val = val; |
787 |
> |
} finally { |
788 |
> |
if (val == null) |
789 |
> |
setTabAt(tab, i, null); |
790 |
> |
if (!node.casHash(fh, h)) { |
791 |
> |
node.hash = h; |
792 |
> |
synchronized (node) { node.notifyAll(); }; |
793 |
> |
} |
794 |
> |
} |
795 |
> |
} |
796 |
> |
if (validated) |
797 |
> |
break; |
798 |
> |
} |
799 |
> |
else if ((fh = f.hash) == MOVED) |
800 |
> |
tab = (Node[])f.key; |
801 |
> |
else if ((fh & HASH_BITS) == h && (fv = f.val) != null && |
802 |
> |
((fk = f.key) == k || k.equals(fk))) |
803 |
> |
return fv; |
804 |
> |
else { |
805 |
> |
Node g = f.next; |
806 |
> |
if (g != null) { |
807 |
> |
for (Node e = g;;) { |
808 |
> |
Object ek, ev; |
809 |
> |
if ((e.hash & HASH_BITS) == h && (ev = e.val) != null && |
810 |
> |
((ek = e.key) == k || k.equals(ek))) |
811 |
> |
return ev; |
812 |
> |
if ((e = e.next) == null) { |
813 |
> |
checkForResize(); |
814 |
> |
break; |
815 |
> |
} |
816 |
> |
} |
817 |
> |
} |
818 |
> |
if (((fh = f.hash) & LOCKED) != 0) { |
819 |
> |
checkForResize(); |
820 |
> |
f.tryAwaitLock(tab, i); |
821 |
> |
} |
822 |
> |
else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) { |
823 |
> |
boolean validated = false; |
824 |
> |
try { |
825 |
> |
if (tabAt(tab, i) == f) { |
826 |
> |
validated = true; |
827 |
> |
for (Node e = f;;) { |
828 |
> |
Object ek, ev; |
829 |
> |
if ((e.hash & HASH_BITS) == h && |
830 |
> |
(ev = e.val) != null && |
831 |
> |
((ek = e.key) == k || k.equals(ek))) { |
832 |
> |
val = ev; |
833 |
> |
break; |
834 |
> |
} |
835 |
> |
Node last = e; |
836 |
> |
if ((e = e.next) == null) { |
837 |
> |
if ((val = mf.map(k)) != null) |
838 |
> |
last.next = new Node(h, k, val, null); |
839 |
> |
break; |
840 |
> |
} |
841 |
> |
} |
842 |
> |
} |
843 |
> |
} finally { |
844 |
> |
if (!f.casHash(fh | LOCKED, fh)) { |
845 |
> |
f.hash = fh; |
846 |
> |
synchronized (f) { f.notifyAll(); }; |
847 |
> |
} |
848 |
> |
} |
849 |
> |
if (validated) |
850 |
> |
break; |
851 |
|
} |
852 |
|
} |
853 |
|
} |
854 |
+ |
if (val == null) |
855 |
+ |
throw new NullPointerException(); |
856 |
+ |
counter.add(1L); |
857 |
+ |
return val; |
858 |
|
} |
859 |
|
|
860 |
< |
/** Implementation for computeIfAbsent and compute. Like put, but messier. */ |
860 |
> |
/** Implementation for compute */ |
861 |
|
@SuppressWarnings("unchecked") |
862 |
< |
private final V internalCompute(K k, |
863 |
< |
MappingFunction<? super K, ? extends V> f, |
640 |
< |
boolean replace) { |
862 |
> |
private final Object internalCompute(K k, |
863 |
> |
RemappingFunction<? super K, V> mf) { |
864 |
|
int h = spread(k.hashCode()); |
865 |
< |
V val = null; |
865 |
> |
Object val = null; |
866 |
|
boolean added = false; |
867 |
< |
Node[] tab = table; |
868 |
< |
outer:for (;;) { |
869 |
< |
Node e; int i; Object ek, ev; |
867 |
> |
boolean checkSize = false; |
868 |
> |
for (Node[] tab = table;;) { |
869 |
> |
Node f; int i, fh; |
870 |
|
if (tab == null) |
871 |
< |
tab = growTable(); |
872 |
< |
else if ((e = tabAt(tab, i = (tab.length - 1) & h)) == null) { |
873 |
< |
Node node = new Node(h, k, null, null); |
871 |
> |
tab = initTable(); |
872 |
> |
else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { |
873 |
> |
Node node = new Node(fh = h | LOCKED, k, null, null); |
874 |
|
boolean validated = false; |
875 |
< |
synchronized (node) { // must lock while computing value |
876 |
< |
if (casTabAt(tab, i, null, node)) { |
877 |
< |
validated = true; |
878 |
< |
try { |
879 |
< |
val = f.map(k); |
880 |
< |
if (val != null) { |
881 |
< |
node.val = val; |
882 |
< |
added = true; |
883 |
< |
} |
884 |
< |
} finally { |
885 |
< |
if (!added) |
886 |
< |
setTabAt(tab, i, null); |
875 |
> |
if (casTabAt(tab, i, null, node)) { |
876 |
> |
validated = true; |
877 |
> |
try { |
878 |
> |
if ((val = mf.remap(k, null)) != null) { |
879 |
> |
node.val = val; |
880 |
> |
added = true; |
881 |
> |
} |
882 |
> |
} finally { |
883 |
> |
if (!added) |
884 |
> |
setTabAt(tab, i, null); |
885 |
> |
if (!node.casHash(fh, h)) { |
886 |
> |
node.hash = h; |
887 |
> |
synchronized (node) { node.notifyAll(); }; |
888 |
|
} |
889 |
|
} |
890 |
|
} |
891 |
|
if (validated) |
892 |
|
break; |
893 |
|
} |
894 |
< |
else if (e.hash < 0) |
895 |
< |
tab = (Node[])e.key; |
896 |
< |
else if (!replace && e.hash == h && (ev = e.val) != null && |
897 |
< |
((ek = e.key) == k || k.equals(ek))) { |
898 |
< |
if (tabAt(tab, i) == e) { |
675 |
< |
val = (V)ev; |
676 |
< |
break; |
677 |
< |
} |
894 |
> |
else if ((fh = f.hash) == MOVED) |
895 |
> |
tab = (Node[])f.key; |
896 |
> |
else if ((fh & LOCKED) != 0) { |
897 |
> |
checkForResize(); |
898 |
> |
f.tryAwaitLock(tab, i); |
899 |
|
} |
900 |
< |
else if (Thread.holdsLock(e)) |
680 |
< |
throw new IllegalStateException("Recursive map computation"); |
681 |
< |
else { |
900 |
> |
else if (f.casHash(fh, fh | LOCKED)) { |
901 |
|
boolean validated = false; |
902 |
< |
boolean checkSize = false; |
903 |
< |
synchronized (e) { |
685 |
< |
if (tabAt(tab, i) == e) { |
902 |
> |
try { |
903 |
> |
if (tabAt(tab, i) == f) { |
904 |
|
validated = true; |
905 |
< |
for (Node first = e;;) { |
906 |
< |
if (e.hash == h && |
907 |
< |
((ek = e.key) == k || k.equals(ek)) && |
908 |
< |
((ev = e.val) != null)) { |
909 |
< |
Object fv; |
910 |
< |
if (replace && (fv = f.map(k)) != null) |
911 |
< |
ev = e.val = fv; |
912 |
< |
val = (V)ev; |
905 |
> |
for (Node e = f;;) { |
906 |
> |
Object ek, ev; |
907 |
> |
if ((e.hash & HASH_BITS) == h && |
908 |
> |
(ev = e.val) != null && |
909 |
> |
((ek = e.key) == k || k.equals(ek))) { |
910 |
> |
val = mf.remap(k, (V)ev); |
911 |
> |
if (val != null) |
912 |
> |
e.val = val; |
913 |
|
break; |
914 |
|
} |
915 |
|
Node last = e; |
916 |
|
if ((e = e.next) == null) { |
917 |
< |
if ((val = f.map(k)) != null) { |
917 |
> |
if ((val = mf.remap(k, null)) != null) { |
918 |
|
last.next = new Node(h, k, val, null); |
919 |
|
added = true; |
920 |
< |
if (last != first || tab.length <= 64) |
920 |
> |
if (last != f || tab.length <= 64) |
921 |
|
checkSize = true; |
922 |
|
} |
923 |
|
break; |
924 |
|
} |
925 |
|
} |
926 |
|
} |
927 |
+ |
} finally { |
928 |
+ |
if (!f.casHash(fh | LOCKED, fh)) { |
929 |
+ |
f.hash = fh; |
930 |
+ |
synchronized (f) { f.notifyAll(); }; |
931 |
+ |
} |
932 |
|
} |
933 |
< |
if (validated) { |
711 |
< |
if (checkSize && tab.length < MAXIMUM_CAPACITY && |
712 |
< |
resizing == 0 && counter.sum() >= (long)threshold) |
713 |
< |
growTable(); |
933 |
> |
if (validated) |
934 |
|
break; |
715 |
– |
} |
935 |
|
} |
936 |
|
} |
937 |
< |
if (added) |
938 |
< |
counter.increment(); |
937 |
> |
if (val == null) |
938 |
> |
throw new NullPointerException(); |
939 |
> |
if (added) { |
940 |
> |
counter.add(1L); |
941 |
> |
if (checkSize) |
942 |
> |
checkForResize(); |
943 |
> |
} |
944 |
|
return val; |
945 |
|
} |
946 |
|
|
947 |
+ |
/** Implementation for putAll */ |
948 |
+ |
private final void internalPutAll(Map<?, ?> m) { |
949 |
+ |
tryPresize(m.size()); |
950 |
+ |
long delta = 0L; // number of uncommitted additions |
951 |
+ |
boolean npe = false; // to throw exception on exit for nulls |
952 |
+ |
try { // to clean up counts on other exceptions |
953 |
+ |
for (Map.Entry<?, ?> entry : m.entrySet()) { |
954 |
+ |
Object k, v; |
955 |
+ |
if (entry == null || (k = entry.getKey()) == null || |
956 |
+ |
(v = entry.getValue()) == null) { |
957 |
+ |
npe = true; |
958 |
+ |
break; |
959 |
+ |
} |
960 |
+ |
int h = spread(k.hashCode()); |
961 |
+ |
for (Node[] tab = table;;) { |
962 |
+ |
int i; Node f; int fh; |
963 |
+ |
if (tab == null) |
964 |
+ |
tab = initTable(); |
965 |
+ |
else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){ |
966 |
+ |
if (casTabAt(tab, i, null, new Node(h, k, v, null))) { |
967 |
+ |
++delta; |
968 |
+ |
break; |
969 |
+ |
} |
970 |
+ |
} |
971 |
+ |
else if ((fh = f.hash) == MOVED) |
972 |
+ |
tab = (Node[])f.key; |
973 |
+ |
else if ((fh & LOCKED) != 0) { |
974 |
+ |
counter.add(delta); |
975 |
+ |
delta = 0L; |
976 |
+ |
checkForResize(); |
977 |
+ |
f.tryAwaitLock(tab, i); |
978 |
+ |
} |
979 |
+ |
else if (f.casHash(fh, fh | LOCKED)) { |
980 |
+ |
boolean validated = false; |
981 |
+ |
boolean tooLong = false; |
982 |
+ |
try { |
983 |
+ |
if (tabAt(tab, i) == f) { |
984 |
+ |
validated = true; |
985 |
+ |
for (Node e = f;;) { |
986 |
+ |
Object ek, ev; |
987 |
+ |
if ((e.hash & HASH_BITS) == h && |
988 |
+ |
(ev = e.val) != null && |
989 |
+ |
((ek = e.key) == k || k.equals(ek))) { |
990 |
+ |
e.val = v; |
991 |
+ |
break; |
992 |
+ |
} |
993 |
+ |
Node last = e; |
994 |
+ |
if ((e = e.next) == null) { |
995 |
+ |
++delta; |
996 |
+ |
last.next = new Node(h, k, v, null); |
997 |
+ |
break; |
998 |
+ |
} |
999 |
+ |
tooLong = true; |
1000 |
+ |
} |
1001 |
+ |
} |
1002 |
+ |
} finally { |
1003 |
+ |
if (!f.casHash(fh | LOCKED, fh)) { |
1004 |
+ |
f.hash = fh; |
1005 |
+ |
synchronized (f) { f.notifyAll(); }; |
1006 |
+ |
} |
1007 |
+ |
} |
1008 |
+ |
if (validated) { |
1009 |
+ |
if (tooLong) { |
1010 |
+ |
counter.add(delta); |
1011 |
+ |
delta = 0L; |
1012 |
+ |
checkForResize(); |
1013 |
+ |
} |
1014 |
+ |
break; |
1015 |
+ |
} |
1016 |
+ |
} |
1017 |
+ |
} |
1018 |
+ |
} |
1019 |
+ |
} finally { |
1020 |
+ |
if (delta != 0) |
1021 |
+ |
counter.add(delta); |
1022 |
+ |
} |
1023 |
+ |
if (npe) |
1024 |
+ |
throw new NullPointerException(); |
1025 |
+ |
} |
1026 |
+ |
|
1027 |
+ |
/* ---------------- Table Initialization and Resizing -------------- */ |
1028 |
+ |
|
1029 |
+ |
/** |
1030 |
+ |
* Returns a power of two table size for the given desired capacity. |
1031 |
+ |
* See Hackers Delight, sec 3.2 |
1032 |
+ |
*/ |
1033 |
+ |
private static final int tableSizeFor(int c) { |
1034 |
+ |
int n = c - 1; |
1035 |
+ |
n |= n >>> 1; |
1036 |
+ |
n |= n >>> 2; |
1037 |
+ |
n |= n >>> 4; |
1038 |
+ |
n |= n >>> 8; |
1039 |
+ |
n |= n >>> 16; |
1040 |
+ |
return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1; |
1041 |
+ |
} |
1042 |
+ |
|
1043 |
+ |
/** |
1044 |
+ |
* Initializes table, using the size recorded in sizeCtl. |
1045 |
+ |
*/ |
1046 |
+ |
private final Node[] initTable() { |
1047 |
+ |
Node[] tab; int sc; |
1048 |
+ |
while ((tab = table) == null) { |
1049 |
+ |
if ((sc = sizeCtl) < 0) |
1050 |
+ |
Thread.yield(); // lost initialization race; just spin |
1051 |
+ |
else if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { |
1052 |
+ |
try { |
1053 |
+ |
if ((tab = table) == null) { |
1054 |
+ |
int n = (sc > 0) ? sc : DEFAULT_CAPACITY; |
1055 |
+ |
tab = table = new Node[n]; |
1056 |
+ |
sc = n - (n >>> 2); |
1057 |
+ |
} |
1058 |
+ |
} finally { |
1059 |
+ |
sizeCtl = sc; |
1060 |
+ |
} |
1061 |
+ |
break; |
1062 |
+ |
} |
1063 |
+ |
} |
1064 |
+ |
return tab; |
1065 |
+ |
} |
1066 |
+ |
|
1067 |
+ |
/** |
1068 |
+ |
* If table is too small and not already resizing, creates next |
1069 |
+ |
* table and transfers bins. Rechecks occupancy after a transfer |
1070 |
+ |
* to see if another resize is already needed because resizings |
1071 |
+ |
* are lagging additions. |
1072 |
+ |
*/ |
1073 |
+ |
private final void checkForResize() { |
1074 |
+ |
Node[] tab; int n, sc; |
1075 |
+ |
while ((tab = table) != null && |
1076 |
+ |
(n = tab.length) < MAXIMUM_CAPACITY && |
1077 |
+ |
(sc = sizeCtl) >= 0 && counter.sum() >= (long)sc && |
1078 |
+ |
UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { |
1079 |
+ |
try { |
1080 |
+ |
if (tab == table) { |
1081 |
+ |
table = rebuild(tab); |
1082 |
+ |
sc = (n << 1) - (n >>> 1); |
1083 |
+ |
} |
1084 |
+ |
} finally { |
1085 |
+ |
sizeCtl = sc; |
1086 |
+ |
} |
1087 |
+ |
} |
1088 |
+ |
} |
1089 |
+ |
|
1090 |
+ |
/** |
1091 |
+ |
* Tries to presize table to accommodate the given number of elements. |
1092 |
+ |
* |
1093 |
+ |
* @param size number of elements (doesn't need to be perfectly accurate) |
1094 |
+ |
*/ |
1095 |
+ |
private final void tryPresize(int size) { |
1096 |
+ |
int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY : |
1097 |
+ |
tableSizeFor(size + (size >>> 1) + 1); |
1098 |
+ |
int sc; |
1099 |
+ |
while ((sc = sizeCtl) >= 0) { |
1100 |
+ |
Node[] tab = table; int n; |
1101 |
+ |
if (tab == null || (n = tab.length) == 0) { |
1102 |
+ |
n = (sc > c) ? sc : c; |
1103 |
+ |
if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { |
1104 |
+ |
try { |
1105 |
+ |
if (table == tab) { |
1106 |
+ |
table = new Node[n]; |
1107 |
+ |
sc = n - (n >>> 2); |
1108 |
+ |
} |
1109 |
+ |
} finally { |
1110 |
+ |
sizeCtl = sc; |
1111 |
+ |
} |
1112 |
+ |
} |
1113 |
+ |
} |
1114 |
+ |
else if (c <= sc || n >= MAXIMUM_CAPACITY) |
1115 |
+ |
break; |
1116 |
+ |
else if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { |
1117 |
+ |
try { |
1118 |
+ |
if (table == tab) { |
1119 |
+ |
table = rebuild(tab); |
1120 |
+ |
sc = (n << 1) - (n >>> 1); |
1121 |
+ |
} |
1122 |
+ |
} finally { |
1123 |
+ |
sizeCtl = sc; |
1124 |
+ |
} |
1125 |
+ |
} |
1126 |
+ |
} |
1127 |
+ |
} |
1128 |
+ |
|
1129 |
+ |
/* |
1130 |
+ |
* Moves and/or copies the nodes in each bin to new table. See |
1131 |
+ |
* above for explanation. |
1132 |
+ |
* |
1133 |
+ |
* @return the new table |
1134 |
+ |
*/ |
1135 |
+ |
private static final Node[] rebuild(Node[] tab) { |
1136 |
+ |
int n = tab.length; |
1137 |
+ |
Node[] nextTab = new Node[n << 1]; |
1138 |
+ |
Node fwd = new Node(MOVED, nextTab, null, null); |
1139 |
+ |
int[] buffer = null; // holds bins to revisit; null until needed |
1140 |
+ |
Node rev = null; // reverse forwarder; null until needed |
1141 |
+ |
int nbuffered = 0; // the number of bins in buffer list |
1142 |
+ |
int bufferIndex = 0; // buffer index of current buffered bin |
1143 |
+ |
int bin = n - 1; // current non-buffered bin or -1 if none |
1144 |
+ |
|
1145 |
+ |
for (int i = bin;;) { // start upwards sweep |
1146 |
+ |
int fh; Node f; |
1147 |
+ |
if ((f = tabAt(tab, i)) == null) { |
1148 |
+ |
if (bin >= 0) { // no lock needed (or available) |
1149 |
+ |
if (!casTabAt(tab, i, f, fwd)) |
1150 |
+ |
continue; |
1151 |
+ |
} |
1152 |
+ |
else { // transiently use a locked forwarding node |
1153 |
+ |
Node g = new Node(MOVED|LOCKED, nextTab, null, null); |
1154 |
+ |
if (!casTabAt(tab, i, f, g)) |
1155 |
+ |
continue; |
1156 |
+ |
setTabAt(nextTab, i, null); |
1157 |
+ |
setTabAt(nextTab, i + n, null); |
1158 |
+ |
setTabAt(tab, i, fwd); |
1159 |
+ |
if (!g.casHash(MOVED|LOCKED, MOVED)) { |
1160 |
+ |
g.hash = MOVED; |
1161 |
+ |
synchronized (g) { g.notifyAll(); } |
1162 |
+ |
} |
1163 |
+ |
} |
1164 |
+ |
} |
1165 |
+ |
else if (((fh = f.hash) & LOCKED) == 0 && f.casHash(fh, fh|LOCKED)) { |
1166 |
+ |
boolean validated = false; |
1167 |
+ |
try { // split to lo and hi lists; copying as needed |
1168 |
+ |
if (tabAt(tab, i) == f) { |
1169 |
+ |
validated = true; |
1170 |
+ |
Node e = f, lastRun = f; |
1171 |
+ |
Node lo = null, hi = null; |
1172 |
+ |
int runBit = e.hash & n; |
1173 |
+ |
for (Node p = e.next; p != null; p = p.next) { |
1174 |
+ |
int b = p.hash & n; |
1175 |
+ |
if (b != runBit) { |
1176 |
+ |
runBit = b; |
1177 |
+ |
lastRun = p; |
1178 |
+ |
} |
1179 |
+ |
} |
1180 |
+ |
if (runBit == 0) |
1181 |
+ |
lo = lastRun; |
1182 |
+ |
else |
1183 |
+ |
hi = lastRun; |
1184 |
+ |
for (Node p = e; p != lastRun; p = p.next) { |
1185 |
+ |
int ph = p.hash & HASH_BITS; |
1186 |
+ |
Object pk = p.key, pv = p.val; |
1187 |
+ |
if ((ph & n) == 0) |
1188 |
+ |
lo = new Node(ph, pk, pv, lo); |
1189 |
+ |
else |
1190 |
+ |
hi = new Node(ph, pk, pv, hi); |
1191 |
+ |
} |
1192 |
+ |
setTabAt(nextTab, i, lo); |
1193 |
+ |
setTabAt(nextTab, i + n, hi); |
1194 |
+ |
setTabAt(tab, i, fwd); |
1195 |
+ |
} |
1196 |
+ |
} finally { |
1197 |
+ |
if (!f.casHash(fh | LOCKED, fh)) { |
1198 |
+ |
f.hash = fh; |
1199 |
+ |
synchronized (f) { f.notifyAll(); }; |
1200 |
+ |
} |
1201 |
+ |
} |
1202 |
+ |
if (!validated) |
1203 |
+ |
continue; |
1204 |
+ |
} |
1205 |
+ |
else { |
1206 |
+ |
if (buffer == null) // initialize buffer for revisits |
1207 |
+ |
buffer = new int[TRANSFER_BUFFER_SIZE]; |
1208 |
+ |
if (bin < 0 && bufferIndex > 0) { |
1209 |
+ |
int j = buffer[--bufferIndex]; |
1210 |
+ |
buffer[bufferIndex] = i; |
1211 |
+ |
i = j; // swap with another bin |
1212 |
+ |
continue; |
1213 |
+ |
} |
1214 |
+ |
if (bin < 0 || nbuffered >= TRANSFER_BUFFER_SIZE) { |
1215 |
+ |
f.tryAwaitLock(tab, i); |
1216 |
+ |
continue; // no other options -- block |
1217 |
+ |
} |
1218 |
+ |
if (rev == null) // initialize reverse-forwarder |
1219 |
+ |
rev = new Node(MOVED, tab, null, null); |
1220 |
+ |
if (tabAt(tab, i) != f || (f.hash & LOCKED) == 0) |
1221 |
+ |
continue; // recheck before adding to list |
1222 |
+ |
buffer[nbuffered++] = i; |
1223 |
+ |
setTabAt(nextTab, i, rev); // install place-holders |
1224 |
+ |
setTabAt(nextTab, i + n, rev); |
1225 |
+ |
} |
1226 |
+ |
|
1227 |
+ |
if (bin > 0) |
1228 |
+ |
i = --bin; |
1229 |
+ |
else if (buffer != null && nbuffered > 0) { |
1230 |
+ |
bin = -1; |
1231 |
+ |
i = buffer[bufferIndex = --nbuffered]; |
1232 |
+ |
} |
1233 |
+ |
else |
1234 |
+ |
return nextTab; |
1235 |
+ |
} |
1236 |
+ |
} |
1237 |
+ |
|
1238 |
|
/** |
1239 |
< |
* Implementation for clear. Steps through each bin, removing all nodes. |
1239 |
> |
* Implementation for clear. Steps through each bin, removing all |
1240 |
> |
* nodes. |
1241 |
|
*/ |
1242 |
|
private final void internalClear() { |
1243 |
|
long delta = 0L; // negative number of deletions |
1244 |
|
int i = 0; |
1245 |
|
Node[] tab = table; |
1246 |
|
while (tab != null && i < tab.length) { |
1247 |
< |
Node e = tabAt(tab, i); |
1248 |
< |
if (e == null) |
1247 |
> |
int fh; |
1248 |
> |
Node f = tabAt(tab, i); |
1249 |
> |
if (f == null) |
1250 |
|
++i; |
1251 |
< |
else if (e.hash < 0) |
1252 |
< |
tab = (Node[])e.key; |
1253 |
< |
else { |
1251 |
> |
else if ((fh = f.hash) == MOVED) |
1252 |
> |
tab = (Node[])f.key; |
1253 |
> |
else if ((fh & LOCKED) != 0) { |
1254 |
> |
counter.add(delta); // opportunistically update count |
1255 |
> |
delta = 0L; |
1256 |
> |
f.tryAwaitLock(tab, i); |
1257 |
> |
} |
1258 |
> |
else if (f.casHash(fh, fh | LOCKED)) { |
1259 |
|
boolean validated = false; |
1260 |
< |
synchronized (e) { |
1261 |
< |
if (tabAt(tab, i) == e) { |
1260 |
> |
try { |
1261 |
> |
if (tabAt(tab, i) == f) { |
1262 |
|
validated = true; |
1263 |
< |
Node en; |
742 |
< |
do { |
743 |
< |
en = e.next; |
1263 |
> |
for (Node e = f; e != null; e = e.next) { |
1264 |
|
if (e.val != null) { // currently always true |
1265 |
|
e.val = null; |
1266 |
|
--delta; |
1267 |
|
} |
1268 |
< |
} while ((e = en) != null); |
1268 |
> |
} |
1269 |
|
setTabAt(tab, i, null); |
1270 |
|
} |
1271 |
+ |
} finally { |
1272 |
+ |
if (!f.casHash(fh | LOCKED, fh)) { |
1273 |
+ |
f.hash = fh; |
1274 |
+ |
synchronized (f) { f.notifyAll(); }; |
1275 |
+ |
} |
1276 |
|
} |
1277 |
|
if (validated) |
1278 |
|
++i; |
1279 |
|
} |
1280 |
|
} |
1281 |
< |
counter.add(delta); |
1281 |
> |
if (delta != 0) |
1282 |
> |
counter.add(delta); |
1283 |
|
} |
1284 |
|
|
1285 |
+ |
|
1286 |
|
/* ----------------Table Traversal -------------- */ |
1287 |
|
|
1288 |
|
/** |
1298 |
|
* valid. |
1299 |
|
* |
1300 |
|
* Internal traversals directly access these fields, as in: |
1301 |
< |
* {@code while (it.next != null) { process(nextKey); it.advance(); }} |
1301 |
> |
* {@code while (it.next != null) { process(it.nextKey); it.advance(); }} |
1302 |
|
* |
1303 |
|
* Exported iterators (subclasses of ViewIterator) extract key, |
1304 |
|
* value, or key-value pairs as return values of Iterator.next(), |
1305 |
|
* and encapsulate the it.next check as hasNext(); |
1306 |
|
* |
1307 |
< |
* The iterator visits each valid node that was reachable upon |
1308 |
< |
* iterator construction once. It might miss some that were added |
1309 |
< |
* to a bin after the bin was visited, which is OK wrt consistency |
1310 |
< |
* guarantees. Maintaining this property in the face of possible |
1311 |
< |
* ongoing resizes requires a fair amount of bookkeeping state |
1312 |
< |
* that is difficult to optimize away amidst volatile accesses. |
1313 |
< |
* Even so, traversal maintains reasonable throughput. |
1307 |
> |
* The iterator visits once each still-valid node that was |
1308 |
> |
* reachable upon iterator construction. It might miss some that |
1309 |
> |
* were added to a bin after the bin was visited, which is OK wrt |
1310 |
> |
* consistency guarantees. Maintaining this property in the face |
1311 |
> |
* of possible ongoing resizes requires a fair amount of |
1312 |
> |
* bookkeeping state that is difficult to optimize away amidst |
1313 |
> |
* volatile accesses. Even so, traversal maintains reasonable |
1314 |
> |
* throughput. |
1315 |
|
* |
1316 |
|
* Normally, iteration proceeds bin-by-bin traversing lists. |
1317 |
|
* However, if the table has been resized, then all future steps |
1349 |
|
this.tab = tab; |
1350 |
|
baseSize = (tab == null) ? 0 : tab.length; |
1351 |
|
baseLimit = (hi <= baseSize) ? hi : baseSize; |
1352 |
< |
index = baseIndex = lo; |
1352 |
> |
index = baseIndex = (lo >= 0) ? lo : 0; |
1353 |
|
next = null; |
1354 |
|
advance(); |
1355 |
|
} |
1358 |
|
final void advance() { |
1359 |
|
Node e = last = next; |
1360 |
|
outer: do { |
1361 |
< |
if (e != null) // pass used or skipped node |
1361 |
> |
if (e != null) // advance past used/skipped node |
1362 |
|
e = e.next; |
1363 |
< |
while (e == null) { // get to next non-null bin |
1364 |
< |
Node[] t; int b, i, n; // checks must use locals |
1363 |
> |
while (e == null) { // get to next non-null bin |
1364 |
> |
Node[] t; int b, i, n; // checks must use locals |
1365 |
|
if ((b = baseIndex) >= baseLimit || (i = index) < 0 || |
1366 |
|
(t = tab) == null || i >= (n = t.length)) |
1367 |
|
break outer; |
1368 |
< |
else if ((e = tabAt(t, i)) != null && e.hash < 0) |
1369 |
< |
tab = (Node[])e.key; // restarts due to null val |
1370 |
< |
else // visit upper slots if present |
1368 |
> |
else if ((e = tabAt(t, i)) != null && e.hash == MOVED) |
1369 |
> |
tab = (Node[])e.key; // restarts due to null val |
1370 |
> |
else // visit upper slots if present |
1371 |
|
index = (i += baseSize) < n ? i : (baseIndex = b + 1); |
1372 |
|
} |
1373 |
|
nextKey = e.key; |
1374 |
< |
} while ((nextVal = e.val) == null); // skip deleted or special nodes |
1374 |
> |
} while ((nextVal = e.val) == null);// skip deleted or special nodes |
1375 |
|
next = e; |
1376 |
|
} |
1377 |
|
} |
1383 |
|
*/ |
1384 |
|
public ConcurrentHashMapV8() { |
1385 |
|
this.counter = new LongAdder(); |
858 |
– |
this.targetCapacity = DEFAULT_CAPACITY; |
1386 |
|
} |
1387 |
|
|
1388 |
|
/** |
1402 |
|
MAXIMUM_CAPACITY : |
1403 |
|
tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1)); |
1404 |
|
this.counter = new LongAdder(); |
1405 |
< |
this.targetCapacity = cap; |
1405 |
> |
this.sizeCtl = cap; |
1406 |
|
} |
1407 |
|
|
1408 |
|
/** |
1412 |
|
*/ |
1413 |
|
public ConcurrentHashMapV8(Map<? extends K, ? extends V> m) { |
1414 |
|
this.counter = new LongAdder(); |
1415 |
< |
this.targetCapacity = DEFAULT_CAPACITY; |
1416 |
< |
putAll(m); |
1415 |
> |
this.sizeCtl = DEFAULT_CAPACITY; |
1416 |
> |
internalPutAll(m); |
1417 |
|
} |
1418 |
|
|
1419 |
|
/** |
1428 |
|
* establishing the initial table size |
1429 |
|
* @throws IllegalArgumentException if the initial capacity of |
1430 |
|
* elements is negative or the load factor is nonpositive |
1431 |
+ |
* |
1432 |
+ |
* @since 1.6 |
1433 |
|
*/ |
1434 |
|
public ConcurrentHashMapV8(int initialCapacity, float loadFactor) { |
1435 |
|
this(initialCapacity, loadFactor, 1); |
1460 |
|
if (initialCapacity < concurrencyLevel) // Use at least as many bins |
1461 |
|
initialCapacity = concurrencyLevel; // as estimated threads |
1462 |
|
long size = (long)(1.0 + (long)initialCapacity / loadFactor); |
1463 |
< |
int cap = ((size >= (long)MAXIMUM_CAPACITY) ? |
1464 |
< |
MAXIMUM_CAPACITY: tableSizeFor((int)size)); |
1463 |
> |
int cap = ((size >= (long)MAXIMUM_CAPACITY) ? |
1464 |
> |
MAXIMUM_CAPACITY: tableSizeFor((int)size)); |
1465 |
|
this.counter = new LongAdder(); |
1466 |
< |
this.targetCapacity = cap; |
1466 |
> |
this.sizeCtl = cap; |
1467 |
|
} |
1468 |
|
|
1469 |
|
/** |
1483 |
|
(int)n); |
1484 |
|
} |
1485 |
|
|
1486 |
+ |
final long longSize() { // accurate version of size needed for views |
1487 |
+ |
long n = counter.sum(); |
1488 |
+ |
return (n < 0L) ? 0L : n; |
1489 |
+ |
} |
1490 |
+ |
|
1491 |
|
/** |
1492 |
|
* Returns the value to which the specified key is mapped, |
1493 |
|
* or {@code null} if this map contains no mapping for the key. |
1580 |
|
public V put(K key, V value) { |
1581 |
|
if (key == null || value == null) |
1582 |
|
throw new NullPointerException(); |
1583 |
< |
return (V)internalPut(key, value, true); |
1583 |
> |
return (V)internalPut(key, value); |
1584 |
|
} |
1585 |
|
|
1586 |
|
/** |
1594 |
|
public V putIfAbsent(K key, V value) { |
1595 |
|
if (key == null || value == null) |
1596 |
|
throw new NullPointerException(); |
1597 |
< |
return (V)internalPut(key, value, false); |
1597 |
> |
return (V)internalPutIfAbsent(key, value); |
1598 |
|
} |
1599 |
|
|
1600 |
|
/** |
1605 |
|
* @param m mappings to be stored in this map |
1606 |
|
*/ |
1607 |
|
public void putAll(Map<? extends K, ? extends V> m) { |
1608 |
< |
if (m == null) |
1075 |
< |
throw new NullPointerException(); |
1076 |
< |
/* |
1077 |
< |
* If uninitialized, try to adjust targetCapacity to |
1078 |
< |
* accommodate the given number of elements. |
1079 |
< |
*/ |
1080 |
< |
if (table == null) { |
1081 |
< |
int size = m.size(); |
1082 |
< |
int cap = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY : |
1083 |
< |
tableSizeFor(size + (size >>> 1) + 1); |
1084 |
< |
if (cap > targetCapacity) |
1085 |
< |
targetCapacity = cap; |
1086 |
< |
} |
1087 |
< |
for (Map.Entry<? extends K, ? extends V> e : m.entrySet()) |
1088 |
< |
put(e.getKey(), e.getValue()); |
1608 |
> |
internalPutAll(m); |
1609 |
|
} |
1610 |
|
|
1611 |
|
/** |
1612 |
|
* If the specified key is not already associated with a value, |
1613 |
< |
* computes its value using the given mappingFunction, and if |
1614 |
< |
* non-null, enters it into the map. This is equivalent to |
1615 |
< |
* <pre> {@code |
1613 |
> |
* computes its value using the given mappingFunction and |
1614 |
> |
* enters it into the map. This is equivalent to |
1615 |
> |
* <pre> {@code |
1616 |
|
* if (map.containsKey(key)) |
1617 |
|
* return map.get(key); |
1618 |
|
* value = mappingFunction.map(key); |
1619 |
< |
* if (value != null) |
1100 |
< |
* map.put(key, value); |
1619 |
> |
* map.put(key, value); |
1620 |
|
* return value;}</pre> |
1621 |
|
* |
1622 |
< |
* except that the action is performed atomically. Some attempted |
1623 |
< |
* update operations on this map by other threads may be blocked |
1624 |
< |
* while computation is in progress, so the computation should be |
1625 |
< |
* short and simple, and must not attempt to update any other |
1626 |
< |
* mappings of this Map. The most appropriate usage is to |
1627 |
< |
* construct a new object serving as an initial mapped value, or |
1628 |
< |
* memoized result, as in: |
1622 |
> |
* except that the action is performed atomically. If the |
1623 |
> |
* function returns {@code null} (in which case a {@code |
1624 |
> |
* NullPointerException} is thrown), or the function itself throws |
1625 |
> |
* an (unchecked) exception, the exception is rethrown to its |
1626 |
> |
* caller, and no mapping is recorded. Some attempted update |
1627 |
> |
* operations on this map by other threads may be blocked while |
1628 |
> |
* computation is in progress, so the computation should be short |
1629 |
> |
* and simple, and must not attempt to update any other mappings |
1630 |
> |
* of this Map. The most appropriate usage is to construct a new |
1631 |
> |
* object serving as an initial mapped value, or memoized result, |
1632 |
> |
* as in: |
1633 |
> |
* |
1634 |
|
* <pre> {@code |
1635 |
|
* map.computeIfAbsent(key, new MappingFunction<K, V>() { |
1636 |
|
* public V map(K k) { return new Value(f(k)); }});}</pre> |
1638 |
|
* @param key key with which the specified value is to be associated |
1639 |
|
* @param mappingFunction the function to compute a value |
1640 |
|
* @return the current (existing or computed) value associated with |
1641 |
< |
* the specified key, or {@code null} if the computation |
1642 |
< |
* returned {@code null} |
1643 |
< |
* @throws NullPointerException if the specified key or mappingFunction |
1120 |
< |
* is null |
1641 |
> |
* the specified key. |
1642 |
> |
* @throws NullPointerException if the specified key, mappingFunction, |
1643 |
> |
* or computed value is null |
1644 |
|
* @throws IllegalStateException if the computation detectably |
1645 |
|
* attempts a recursive update to this map that would |
1646 |
|
* otherwise never complete |
1647 |
|
* @throws RuntimeException or Error if the mappingFunction does so, |
1648 |
|
* in which case the mapping is left unestablished |
1649 |
|
*/ |
1650 |
+ |
@SuppressWarnings("unchecked") |
1651 |
|
public V computeIfAbsent(K key, MappingFunction<? super K, ? extends V> mappingFunction) { |
1652 |
|
if (key == null || mappingFunction == null) |
1653 |
|
throw new NullPointerException(); |
1654 |
< |
return internalCompute(key, mappingFunction, false); |
1654 |
> |
return (V)internalComputeIfAbsent(key, mappingFunction); |
1655 |
|
} |
1656 |
|
|
1657 |
|
/** |
1658 |
< |
* Computes the value associated with the given key using the given |
1659 |
< |
* mappingFunction, and if non-null, enters it into the map. This |
1660 |
< |
* is equivalent to |
1658 |
> |
* Computes and enters a new mapping value given a key and |
1659 |
> |
* its current mapped value (or {@code null} if there is no current |
1660 |
> |
* mapping). This is equivalent to |
1661 |
|
* <pre> {@code |
1662 |
< |
* value = mappingFunction.map(key); |
1663 |
< |
* if (value != null) |
1140 |
< |
* map.put(key, value); |
1141 |
< |
* else |
1142 |
< |
* value = map.get(key); |
1143 |
< |
* return value;}</pre> |
1662 |
> |
* map.put(key, remappingFunction.remap(key, map.get(key)); |
1663 |
> |
* }</pre> |
1664 |
|
* |
1665 |
< |
* except that the action is performed atomically. Some attempted |
1665 |
> |
* except that the action is performed atomically. If the |
1666 |
> |
* function returns {@code null} (in which case a {@code |
1667 |
> |
* NullPointerException} is thrown), or the function itself throws |
1668 |
> |
* an (unchecked) exception, the exception is rethrown to its |
1669 |
> |
* caller, and current mapping is left unchanged. Some attempted |
1670 |
|
* update operations on this map by other threads may be blocked |
1671 |
|
* while computation is in progress, so the computation should be |
1672 |
|
* short and simple, and must not attempt to update any other |
1673 |
< |
* mappings of this Map. |
1673 |
> |
* mappings of this Map. For example, to either create or |
1674 |
> |
* append new messages to a value mapping: |
1675 |
> |
* |
1676 |
> |
* <pre> {@code |
1677 |
> |
* Map<Key, String> map = ...; |
1678 |
> |
* final String msg = ...; |
1679 |
> |
* map.compute(key, new RemappingFunction<Key, String>() { |
1680 |
> |
* public String remap(Key k, String v) { |
1681 |
> |
* return (v == null) ? msg : v + msg;});}}</pre> |
1682 |
|
* |
1683 |
|
* @param key key with which the specified value is to be associated |
1684 |
< |
* @param mappingFunction the function to compute a value |
1685 |
< |
* @return the current value associated with |
1686 |
< |
* the specified key, or {@code null} if the computation |
1687 |
< |
* returned {@code null} and the value was not otherwise present |
1688 |
< |
* @throws NullPointerException if the specified key or mappingFunction |
1157 |
< |
* is null |
1684 |
> |
* @param remappingFunction the function to compute a value |
1685 |
> |
* @return the new value associated with |
1686 |
> |
* the specified key. |
1687 |
> |
* @throws NullPointerException if the specified key or remappingFunction |
1688 |
> |
* or computed value is null |
1689 |
|
* @throws IllegalStateException if the computation detectably |
1690 |
|
* attempts a recursive update to this map that would |
1691 |
|
* otherwise never complete |
1692 |
< |
* @throws RuntimeException or Error if the mappingFunction does so, |
1692 |
> |
* @throws RuntimeException or Error if the remappingFunction does so, |
1693 |
|
* in which case the mapping is unchanged |
1694 |
|
*/ |
1695 |
< |
public V compute(K key, MappingFunction<? super K, ? extends V> mappingFunction) { |
1696 |
< |
if (key == null || mappingFunction == null) |
1695 |
> |
@SuppressWarnings("unchecked") |
1696 |
> |
public V compute(K key, RemappingFunction<? super K, V> remappingFunction) { |
1697 |
> |
if (key == null || remappingFunction == null) |
1698 |
|
throw new NullPointerException(); |
1699 |
< |
return internalCompute(key, mappingFunction, true); |
1699 |
> |
return (V)internalCompute(key, remappingFunction); |
1700 |
|
} |
1701 |
|
|
1702 |
|
/** |
1992 |
|
Object k = nextKey; |
1993 |
|
Object v = nextVal; |
1994 |
|
advance(); |
1995 |
< |
return new WriteThroughEntry<K,V>(map, (K)k, (V)v); |
1995 |
> |
return new WriteThroughEntry<K,V>((K)k, (V)v, map); |
1996 |
> |
} |
1997 |
> |
} |
1998 |
> |
|
1999 |
> |
static final class SnapshotEntryIterator<K,V> extends ViewIterator<K,V> |
2000 |
> |
implements Iterator<Map.Entry<K,V>> { |
2001 |
> |
SnapshotEntryIterator(ConcurrentHashMapV8<K, V> map) { super(map); } |
2002 |
> |
|
2003 |
> |
@SuppressWarnings("unchecked") |
2004 |
> |
public final Map.Entry<K,V> next() { |
2005 |
> |
if (next == null) |
2006 |
> |
throw new NoSuchElementException(); |
2007 |
> |
Object k = nextKey; |
2008 |
> |
Object v = nextVal; |
2009 |
> |
advance(); |
2010 |
> |
return new SnapshotEntry<K,V>((K)k, (V)v); |
2011 |
|
} |
2012 |
|
} |
2013 |
|
|
2014 |
|
/** |
2015 |
< |
* Custom Entry class used by EntryIterator.next(), that relays |
1469 |
< |
* setValue changes to the underlying map. |
2015 |
> |
* Base of writeThrough and Snapshot entry classes |
2016 |
|
*/ |
2017 |
< |
static final class WriteThroughEntry<K,V> implements Map.Entry<K, V> { |
1472 |
< |
final ConcurrentHashMapV8<K, V> map; |
2017 |
> |
static abstract class MapEntry<K,V> implements Map.Entry<K, V> { |
2018 |
|
final K key; // non-null |
2019 |
|
V val; // non-null |
2020 |
< |
WriteThroughEntry(ConcurrentHashMapV8<K, V> map, K key, V val) { |
1476 |
< |
this.map = map; this.key = key; this.val = val; |
1477 |
< |
} |
1478 |
< |
|
2020 |
> |
MapEntry(K key, V val) { this.key = key; this.val = val; } |
2021 |
|
public final K getKey() { return key; } |
2022 |
|
public final V getValue() { return val; } |
2023 |
|
public final int hashCode() { return key.hashCode() ^ val.hashCode(); } |
2032 |
|
(v == val || v.equals(val))); |
2033 |
|
} |
2034 |
|
|
2035 |
+ |
public abstract V setValue(V value); |
2036 |
+ |
} |
2037 |
+ |
|
2038 |
+ |
/** |
2039 |
+ |
* Entry used by EntryIterator.next(), that relays setValue |
2040 |
+ |
* changes to the underlying map. |
2041 |
+ |
*/ |
2042 |
+ |
static final class WriteThroughEntry<K,V> extends MapEntry<K,V> |
2043 |
+ |
implements Map.Entry<K, V> { |
2044 |
+ |
final ConcurrentHashMapV8<K, V> map; |
2045 |
+ |
WriteThroughEntry(K key, V val, ConcurrentHashMapV8<K, V> map) { |
2046 |
+ |
super(key, val); |
2047 |
+ |
this.map = map; |
2048 |
+ |
} |
2049 |
+ |
|
2050 |
|
/** |
2051 |
|
* Sets our entry's value and writes through to the map. The |
2052 |
|
* value to return is somewhat arbitrary here. Since a |
2065 |
|
} |
2066 |
|
} |
2067 |
|
|
2068 |
+ |
/** |
2069 |
+ |
* Internal version of entry, that doesn't write though changes |
2070 |
+ |
*/ |
2071 |
+ |
static final class SnapshotEntry<K,V> extends MapEntry<K,V> |
2072 |
+ |
implements Map.Entry<K, V> { |
2073 |
+ |
SnapshotEntry(K key, V val) { super(key, val); } |
2074 |
+ |
public final V setValue(V value) { // only locally update |
2075 |
+ |
if (value == null) throw new NullPointerException(); |
2076 |
+ |
V v = val; |
2077 |
+ |
val = value; |
2078 |
+ |
return v; |
2079 |
+ |
} |
2080 |
+ |
} |
2081 |
+ |
|
2082 |
|
/* ----------------Views -------------- */ |
2083 |
|
|
2084 |
< |
/* |
2085 |
< |
* These currently just extend java.util.AbstractX classes, but |
2086 |
< |
* may need a new custom base to support partitioned traversal. |
2084 |
> |
/** |
2085 |
> |
* Base class for views. This is done mainly to allow adding |
2086 |
> |
* customized parallel traversals (not yet implemented.) |
2087 |
|
*/ |
2088 |
< |
|
1518 |
< |
static final class KeySet<K,V> extends AbstractSet<K> { |
2088 |
> |
static abstract class MapView<K, V> { |
2089 |
|
final ConcurrentHashMapV8<K, V> map; |
2090 |
< |
KeySet(ConcurrentHashMapV8<K, V> map) { this.map = map; } |
1521 |
< |
|
2090 |
> |
MapView(ConcurrentHashMapV8<K, V> map) { this.map = map; } |
2091 |
|
public final int size() { return map.size(); } |
2092 |
|
public final boolean isEmpty() { return map.isEmpty(); } |
2093 |
|
public final void clear() { map.clear(); } |
2094 |
+ |
|
2095 |
+ |
// implementations below rely on concrete classes supplying these |
2096 |
+ |
abstract Iterator<?> iter(); |
2097 |
+ |
abstract public boolean contains(Object o); |
2098 |
+ |
abstract public boolean remove(Object o); |
2099 |
+ |
|
2100 |
+ |
private static final String oomeMsg = "Required array size too large"; |
2101 |
+ |
|
2102 |
+ |
public final Object[] toArray() { |
2103 |
+ |
long sz = map.longSize(); |
2104 |
+ |
if (sz > (long)(MAX_ARRAY_SIZE)) |
2105 |
+ |
throw new OutOfMemoryError(oomeMsg); |
2106 |
+ |
int n = (int)sz; |
2107 |
+ |
Object[] r = new Object[n]; |
2108 |
+ |
int i = 0; |
2109 |
+ |
Iterator<?> it = iter(); |
2110 |
+ |
while (it.hasNext()) { |
2111 |
+ |
if (i == n) { |
2112 |
+ |
if (n >= MAX_ARRAY_SIZE) |
2113 |
+ |
throw new OutOfMemoryError(oomeMsg); |
2114 |
+ |
if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1) |
2115 |
+ |
n = MAX_ARRAY_SIZE; |
2116 |
+ |
else |
2117 |
+ |
n += (n >>> 1) + 1; |
2118 |
+ |
r = Arrays.copyOf(r, n); |
2119 |
+ |
} |
2120 |
+ |
r[i++] = it.next(); |
2121 |
+ |
} |
2122 |
+ |
return (i == n) ? r : Arrays.copyOf(r, i); |
2123 |
+ |
} |
2124 |
+ |
|
2125 |
+ |
@SuppressWarnings("unchecked") |
2126 |
+ |
public final <T> T[] toArray(T[] a) { |
2127 |
+ |
long sz = map.longSize(); |
2128 |
+ |
if (sz > (long)(MAX_ARRAY_SIZE)) |
2129 |
+ |
throw new OutOfMemoryError(oomeMsg); |
2130 |
+ |
int m = (int)sz; |
2131 |
+ |
T[] r = (a.length >= m) ? a : |
2132 |
+ |
(T[])java.lang.reflect.Array |
2133 |
+ |
.newInstance(a.getClass().getComponentType(), m); |
2134 |
+ |
int n = r.length; |
2135 |
+ |
int i = 0; |
2136 |
+ |
Iterator<?> it = iter(); |
2137 |
+ |
while (it.hasNext()) { |
2138 |
+ |
if (i == n) { |
2139 |
+ |
if (n >= MAX_ARRAY_SIZE) |
2140 |
+ |
throw new OutOfMemoryError(oomeMsg); |
2141 |
+ |
if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1) |
2142 |
+ |
n = MAX_ARRAY_SIZE; |
2143 |
+ |
else |
2144 |
+ |
n += (n >>> 1) + 1; |
2145 |
+ |
r = Arrays.copyOf(r, n); |
2146 |
+ |
} |
2147 |
+ |
r[i++] = (T)it.next(); |
2148 |
+ |
} |
2149 |
+ |
if (a == r && i < n) { |
2150 |
+ |
r[i] = null; // null-terminate |
2151 |
+ |
return r; |
2152 |
+ |
} |
2153 |
+ |
return (i == n) ? r : Arrays.copyOf(r, i); |
2154 |
+ |
} |
2155 |
+ |
|
2156 |
+ |
public final int hashCode() { |
2157 |
+ |
int h = 0; |
2158 |
+ |
for (Iterator<?> it = iter(); it.hasNext();) |
2159 |
+ |
h += it.next().hashCode(); |
2160 |
+ |
return h; |
2161 |
+ |
} |
2162 |
+ |
|
2163 |
+ |
public final String toString() { |
2164 |
+ |
StringBuilder sb = new StringBuilder(); |
2165 |
+ |
sb.append('['); |
2166 |
+ |
Iterator<?> it = iter(); |
2167 |
+ |
if (it.hasNext()) { |
2168 |
+ |
for (;;) { |
2169 |
+ |
Object e = it.next(); |
2170 |
+ |
sb.append(e == this ? "(this Collection)" : e); |
2171 |
+ |
if (!it.hasNext()) |
2172 |
+ |
break; |
2173 |
+ |
sb.append(',').append(' '); |
2174 |
+ |
} |
2175 |
+ |
} |
2176 |
+ |
return sb.append(']').toString(); |
2177 |
+ |
} |
2178 |
+ |
|
2179 |
+ |
public final boolean containsAll(Collection<?> c) { |
2180 |
+ |
if (c != this) { |
2181 |
+ |
for (Iterator<?> it = c.iterator(); it.hasNext();) { |
2182 |
+ |
Object e = it.next(); |
2183 |
+ |
if (e == null || !contains(e)) |
2184 |
+ |
return false; |
2185 |
+ |
} |
2186 |
+ |
} |
2187 |
+ |
return true; |
2188 |
+ |
} |
2189 |
+ |
|
2190 |
+ |
public final boolean removeAll(Collection<?> c) { |
2191 |
+ |
boolean modified = false; |
2192 |
+ |
for (Iterator<?> it = iter(); it.hasNext();) { |
2193 |
+ |
if (c.contains(it.next())) { |
2194 |
+ |
it.remove(); |
2195 |
+ |
modified = true; |
2196 |
+ |
} |
2197 |
+ |
} |
2198 |
+ |
return modified; |
2199 |
+ |
} |
2200 |
+ |
|
2201 |
+ |
public final boolean retainAll(Collection<?> c) { |
2202 |
+ |
boolean modified = false; |
2203 |
+ |
for (Iterator<?> it = iter(); it.hasNext();) { |
2204 |
+ |
if (!c.contains(it.next())) { |
2205 |
+ |
it.remove(); |
2206 |
+ |
modified = true; |
2207 |
+ |
} |
2208 |
+ |
} |
2209 |
+ |
return modified; |
2210 |
+ |
} |
2211 |
+ |
|
2212 |
+ |
} |
2213 |
+ |
|
2214 |
+ |
static final class KeySet<K,V> extends MapView<K,V> implements Set<K> { |
2215 |
+ |
KeySet(ConcurrentHashMapV8<K, V> map) { super(map); } |
2216 |
|
public final boolean contains(Object o) { return map.containsKey(o); } |
2217 |
|
public final boolean remove(Object o) { return map.remove(o) != null; } |
2218 |
+ |
|
2219 |
|
public final Iterator<K> iterator() { |
2220 |
|
return new KeyIterator<K,V>(map); |
2221 |
|
} |
2222 |
+ |
final Iterator<?> iter() { |
2223 |
+ |
return new KeyIterator<K,V>(map); |
2224 |
+ |
} |
2225 |
+ |
public final boolean add(K e) { |
2226 |
+ |
throw new UnsupportedOperationException(); |
2227 |
+ |
} |
2228 |
+ |
public final boolean addAll(Collection<? extends K> c) { |
2229 |
+ |
throw new UnsupportedOperationException(); |
2230 |
+ |
} |
2231 |
+ |
public boolean equals(Object o) { |
2232 |
+ |
Set<?> c; |
2233 |
+ |
return ((o instanceof Set) && |
2234 |
+ |
((c = (Set<?>)o) == this || |
2235 |
+ |
(containsAll(c) && c.containsAll(this)))); |
2236 |
+ |
} |
2237 |
|
} |
2238 |
|
|
2239 |
< |
static final class Values<K,V> extends AbstractCollection<V> { |
2240 |
< |
final ConcurrentHashMapV8<K, V> map; |
2241 |
< |
Values(ConcurrentHashMapV8<K, V> map) { this.map = map; } |
1535 |
< |
|
1536 |
< |
public final int size() { return map.size(); } |
1537 |
< |
public final boolean isEmpty() { return map.isEmpty(); } |
1538 |
< |
public final void clear() { map.clear(); } |
2239 |
> |
static final class Values<K,V> extends MapView<K,V> |
2240 |
> |
implements Collection<V> { |
2241 |
> |
Values(ConcurrentHashMapV8<K, V> map) { super(map); } |
2242 |
|
public final boolean contains(Object o) { return map.containsValue(o); } |
2243 |
+ |
|
2244 |
+ |
public final boolean remove(Object o) { |
2245 |
+ |
if (o != null) { |
2246 |
+ |
Iterator<V> it = new ValueIterator<K,V>(map); |
2247 |
+ |
while (it.hasNext()) { |
2248 |
+ |
if (o.equals(it.next())) { |
2249 |
+ |
it.remove(); |
2250 |
+ |
return true; |
2251 |
+ |
} |
2252 |
+ |
} |
2253 |
+ |
} |
2254 |
+ |
return false; |
2255 |
+ |
} |
2256 |
|
public final Iterator<V> iterator() { |
2257 |
|
return new ValueIterator<K,V>(map); |
2258 |
|
} |
2259 |
+ |
final Iterator<?> iter() { |
2260 |
+ |
return new ValueIterator<K,V>(map); |
2261 |
+ |
} |
2262 |
+ |
public final boolean add(V e) { |
2263 |
+ |
throw new UnsupportedOperationException(); |
2264 |
+ |
} |
2265 |
+ |
public final boolean addAll(Collection<? extends V> c) { |
2266 |
+ |
throw new UnsupportedOperationException(); |
2267 |
+ |
} |
2268 |
|
} |
2269 |
|
|
2270 |
< |
static final class EntrySet<K,V> extends AbstractSet<Map.Entry<K,V>> { |
2271 |
< |
final ConcurrentHashMapV8<K, V> map; |
2272 |
< |
EntrySet(ConcurrentHashMapV8<K, V> map) { this.map = map; } |
1548 |
< |
|
1549 |
< |
public final int size() { return map.size(); } |
1550 |
< |
public final boolean isEmpty() { return map.isEmpty(); } |
1551 |
< |
public final void clear() { map.clear(); } |
1552 |
< |
public final Iterator<Map.Entry<K,V>> iterator() { |
1553 |
< |
return new EntryIterator<K,V>(map); |
1554 |
< |
} |
2270 |
> |
static final class EntrySet<K,V> extends MapView<K,V> |
2271 |
> |
implements Set<Map.Entry<K,V>> { |
2272 |
> |
EntrySet(ConcurrentHashMapV8<K, V> map) { super(map); } |
2273 |
|
|
2274 |
|
public final boolean contains(Object o) { |
2275 |
|
Object k, v, r; Map.Entry<?,?> e; |
2287 |
|
(v = e.getValue()) != null && |
2288 |
|
map.remove(k, v)); |
2289 |
|
} |
2290 |
+ |
|
2291 |
+ |
public final Iterator<Map.Entry<K,V>> iterator() { |
2292 |
+ |
return new EntryIterator<K,V>(map); |
2293 |
+ |
} |
2294 |
+ |
final Iterator<?> iter() { |
2295 |
+ |
return new SnapshotEntryIterator<K,V>(map); |
2296 |
+ |
} |
2297 |
+ |
public final boolean add(Entry<K,V> e) { |
2298 |
+ |
throw new UnsupportedOperationException(); |
2299 |
+ |
} |
2300 |
+ |
public final boolean addAll(Collection<? extends Entry<K,V>> c) { |
2301 |
+ |
throw new UnsupportedOperationException(); |
2302 |
+ |
} |
2303 |
+ |
public boolean equals(Object o) { |
2304 |
+ |
Set<?> c; |
2305 |
+ |
return ((o instanceof Set) && |
2306 |
+ |
((c = (Set<?>)o) == this || |
2307 |
+ |
(containsAll(c) && c.containsAll(this)))); |
2308 |
+ |
} |
2309 |
|
} |
2310 |
|
|
2311 |
|
/* ---------------- Serialization Support -------------- */ |
2359 |
|
throws java.io.IOException, ClassNotFoundException { |
2360 |
|
s.defaultReadObject(); |
2361 |
|
this.segments = null; // unneeded |
2362 |
< |
// initalize transient final field |
2362 |
> |
// initialize transient final field |
2363 |
|
UNSAFE.putObjectVolatile(this, counterOffset, new LongAdder()); |
1627 |
– |
this.targetCapacity = DEFAULT_CAPACITY; |
2364 |
|
|
2365 |
|
// Create all nodes, then place in table once size is known |
2366 |
|
long size = 0L; |
2377 |
|
} |
2378 |
|
if (p != null) { |
2379 |
|
boolean init = false; |
2380 |
< |
if (resizing == 0 && |
2381 |
< |
UNSAFE.compareAndSwapInt(this, resizingOffset, 0, 1)) { |
2380 |
> |
int n; |
2381 |
> |
if (size >= (long)(MAXIMUM_CAPACITY >>> 1)) |
2382 |
> |
n = MAXIMUM_CAPACITY; |
2383 |
> |
else { |
2384 |
> |
int sz = (int)size; |
2385 |
> |
n = tableSizeFor(sz + (sz >>> 1) + 1); |
2386 |
> |
} |
2387 |
> |
int sc = sizeCtl; |
2388 |
> |
if (n > sc && |
2389 |
> |
UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { |
2390 |
|
try { |
2391 |
|
if (table == null) { |
2392 |
|
init = true; |
1649 |
– |
int n; |
1650 |
– |
if (size >= (long)(MAXIMUM_CAPACITY >>> 1)) |
1651 |
– |
n = MAXIMUM_CAPACITY; |
1652 |
– |
else { |
1653 |
– |
int sz = (int)size; |
1654 |
– |
n = tableSizeFor(sz + (sz >>> 1) + 1); |
1655 |
– |
} |
1656 |
– |
threshold = n - (n >>> 2) - THRESHOLD_OFFSET; |
2393 |
|
Node[] tab = new Node[n]; |
2394 |
|
int mask = n - 1; |
2395 |
|
while (p != null) { |
2401 |
|
} |
2402 |
|
table = tab; |
2403 |
|
counter.add(size); |
2404 |
+ |
sc = n - (n >>> 2); |
2405 |
|
} |
2406 |
|
} finally { |
2407 |
< |
resizing = 0; |
2407 |
> |
sizeCtl = sc; |
2408 |
|
} |
2409 |
|
} |
2410 |
|
if (!init) { // Can only happen if unsafely published. |
2411 |
|
while (p != null) { |
2412 |
< |
internalPut(p.key, p.val, true); |
2412 |
> |
internalPut(p.key, p.val); |
2413 |
|
p = p.next; |
2414 |
|
} |
2415 |
|
} |
2419 |
|
// Unsafe mechanics |
2420 |
|
private static final sun.misc.Unsafe UNSAFE; |
2421 |
|
private static final long counterOffset; |
2422 |
< |
private static final long resizingOffset; |
2422 |
> |
private static final long sizeCtlOffset; |
2423 |
|
private static final long ABASE; |
2424 |
|
private static final int ASHIFT; |
2425 |
|
|
2430 |
|
Class<?> k = ConcurrentHashMapV8.class; |
2431 |
|
counterOffset = UNSAFE.objectFieldOffset |
2432 |
|
(k.getDeclaredField("counter")); |
2433 |
< |
resizingOffset = UNSAFE.objectFieldOffset |
2434 |
< |
(k.getDeclaredField("resizing")); |
2433 |
> |
sizeCtlOffset = UNSAFE.objectFieldOffset |
2434 |
> |
(k.getDeclaredField("sizeCtl")); |
2435 |
|
Class<?> sc = Node[].class; |
2436 |
|
ABASE = UNSAFE.arrayBaseOffset(sc); |
2437 |
|
ss = UNSAFE.arrayIndexScale(sc); |