| 12 |
|
import java.io.Serializable; |
| 13 |
|
import java.lang.reflect.ParameterizedType; |
| 14 |
|
import java.lang.reflect.Type; |
| 15 |
+ |
import java.util.AbstractMap; |
| 16 |
|
import java.util.Arrays; |
| 17 |
|
import java.util.Collection; |
| 18 |
|
import java.util.Comparator; |
| 219 |
|
* @param <K> the type of keys maintained by this map |
| 220 |
|
* @param <V> the type of mapped values |
| 221 |
|
*/ |
| 222 |
< |
public class ConcurrentHashMapV8<K,V> |
| 222 |
> |
public class ConcurrentHashMapV8<K,V> extends AbstractMap<K,V> |
| 223 |
|
implements ConcurrentMap<K,V>, Serializable { |
| 224 |
|
private static final long serialVersionUID = 7249069246763182397L; |
| 225 |
|
|
| 447 |
|
* related operations (which is the main reason we cannot use |
| 448 |
|
* existing collections such as TreeMaps). TreeBins contain |
| 449 |
|
* Comparable elements, but may contain others, as well as |
| 450 |
< |
* elements that are Comparable but not necessarily Comparable |
| 451 |
< |
* for the same T, so we cannot invoke compareTo among them. To |
| 452 |
< |
* handle this, the tree is ordered primarily by hash value, then |
| 453 |
< |
* by Comparable.compareTo order if applicable. On lookup at a |
| 454 |
< |
* node, if elements are not comparable or compare as 0 then both |
| 455 |
< |
* left and right children may need to be searched in the case of |
| 456 |
< |
* tied hash values. (This corresponds to the full list search |
| 457 |
< |
* that would be necessary if all elements were non-Comparable and |
| 458 |
< |
* had tied hashes.) The red-black balancing code is updated from |
| 459 |
< |
* pre-jdk-collections |
| 450 |
> |
* elements that are Comparable but not necessarily Comparable for |
| 451 |
> |
* the same T, so we cannot invoke compareTo among them. To handle |
| 452 |
> |
* this, the tree is ordered primarily by hash value, then by |
| 453 |
> |
* Comparable.compareTo order if applicable. On lookup at a node, |
| 454 |
> |
* if elements are not comparable or compare as 0 then both left |
| 455 |
> |
* and right children may need to be searched in the case of tied |
| 456 |
> |
* hash values. (This corresponds to the full list search that |
| 457 |
> |
* would be necessary if all elements were non-Comparable and had |
| 458 |
> |
* tied hashes.) On insertion, to keep a total ordering (or as |
| 459 |
> |
* close as is required here) across rebalancings, we compare |
| 460 |
> |
* classes and identityHashCodes as tie-breakers. The red-black |
| 461 |
> |
* balancing code is updated from pre-jdk-collections |
| 462 |
|
* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java) |
| 463 |
|
* based in turn on Cormen, Leiserson, and Rivest "Introduction to |
| 464 |
|
* Algorithms" (CLR). |
| 488 |
|
* unused "Segment" class that is instantiated in minimal form |
| 489 |
|
* only when serializing. |
| 490 |
|
* |
| 491 |
+ |
* Also, solely for compatibility with previous versions of this |
| 492 |
+ |
* class, it extends AbstractMap, even though all of its methods |
| 493 |
+ |
* are overridden, so it is just useless baggage. |
| 494 |
+ |
* |
| 495 |
|
* This file is organized to make things a little easier to follow |
| 496 |
|
* while reading than they might otherwise: First the main static |
| 497 |
|
* declarations and utilities, then fields, then main public |
| 575 |
|
/* |
| 576 |
|
* Encodings for Node hash fields. See above for explanation. |
| 577 |
|
*/ |
| 578 |
< |
static final int MOVED = 0x8fffffff; // (-1) hash for forwarding nodes |
| 579 |
< |
static final int TREEBIN = 0x80000000; // hash for roots of trees |
| 580 |
< |
static final int RESERVED = 0x80000001; // hash for transient reservations |
| 578 |
> |
static final int MOVED = -1; // hash for forwarding nodes |
| 579 |
> |
static final int TREEBIN = -2; // hash for roots of trees |
| 580 |
> |
static final int RESERVED = -3; // hash for transient reservations |
| 581 |
|
static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash |
| 582 |
|
|
| 583 |
|
/** Number of CPUS, to place bounds on some sizings */ |
| 604 |
|
final int hash; |
| 605 |
|
final K key; |
| 606 |
|
volatile V val; |
| 607 |
< |
Node<K,V> next; |
| 607 |
> |
volatile Node<K,V> next; |
| 608 |
|
|
| 609 |
|
Node(int hash, K key, V val, Node<K,V> next) { |
| 610 |
|
this.hash = hash; |
| 729 |
|
* errors by users, these checks must operate on local variables, |
| 730 |
|
* which accounts for some odd-looking inline assignments below. |
| 731 |
|
* Note that calls to setTabAt always occur within locked regions, |
| 732 |
< |
* and so do not need full volatile semantics, but still require |
| 733 |
< |
* ordering to maintain concurrent readability. |
| 732 |
> |
* and so in principle require only release ordering, not need |
| 733 |
> |
* full volatile semantics, but are currently coded as volatile |
| 734 |
> |
* writes to be conservative. |
| 735 |
|
*/ |
| 736 |
|
|
| 737 |
|
@SuppressWarnings("unchecked") |
| 745 |
|
} |
| 746 |
|
|
| 747 |
|
static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) { |
| 748 |
< |
U.putOrderedObject(tab, ((long)i << ASHIFT) + ABASE, v); |
| 748 |
> |
U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v); |
| 749 |
|
} |
| 750 |
|
|
| 751 |
|
/* ---------------- Fields -------------- */ |
| 1366 |
|
* Saves the state of the {@code ConcurrentHashMapV8} instance to a |
| 1367 |
|
* stream (i.e., serializes it). |
| 1368 |
|
* @param s the stream |
| 1369 |
+ |
* @throws java.io.IOException if an I/O error occurs |
| 1370 |
|
* @serialData |
| 1371 |
|
* the key (Object) and value (Object) |
| 1372 |
|
* for each key-value mapping, followed by a null pair. |
| 1409 |
|
/** |
| 1410 |
|
* Reconstitutes the instance from a stream (that is, deserializes it). |
| 1411 |
|
* @param s the stream |
| 1412 |
+ |
* @throws ClassNotFoundException if the class of a serialized object |
| 1413 |
+ |
* could not be found |
| 1414 |
+ |
* @throws java.io.IOException if an I/O error occurs |
| 1415 |
|
*/ |
| 1416 |
|
private void readObject(java.io.ObjectInputStream s) |
| 1417 |
|
throws java.io.IOException, ClassNotFoundException { |
| 2112 |
|
* |
| 2113 |
|
* @param initialCapacity The implementation performs internal |
| 2114 |
|
* sizing to accommodate this many elements. |
| 2115 |
+ |
* @return the new set |
| 2116 |
|
* @throws IllegalArgumentException if the initial capacity of |
| 2117 |
|
* elements is negative |
| 2105 |
– |
* @return the new set |
| 2118 |
|
* @since 1.8 |
| 2119 |
|
*/ |
| 2120 |
|
public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) { |
| 2152 |
|
} |
| 2153 |
|
|
| 2154 |
|
Node<K,V> find(int h, Object k) { |
| 2155 |
< |
Node<K,V> e; int n; |
| 2156 |
< |
Node<K,V>[] tab = nextTable; |
| 2157 |
< |
if (k != null && tab != null && (n = tab.length) > 0 && |
| 2158 |
< |
(e = tabAt(tab, (n - 1) & h)) != null) { |
| 2159 |
< |
do { |
| 2155 |
> |
// loop to avoid arbitrarily deep recursion on forwarding nodes |
| 2156 |
> |
outer: for (Node<K,V>[] tab = nextTable;;) { |
| 2157 |
> |
Node<K,V> e; int n; |
| 2158 |
> |
if (k == null || tab == null || (n = tab.length) == 0 || |
| 2159 |
> |
(e = tabAt(tab, (n - 1) & h)) == null) |
| 2160 |
> |
return null; |
| 2161 |
> |
for (;;) { |
| 2162 |
|
int eh; K ek; |
| 2163 |
|
if ((eh = e.hash) == h && |
| 2164 |
|
((ek = e.key) == k || (ek != null && k.equals(ek)))) |
| 2165 |
|
return e; |
| 2166 |
< |
if (eh < 0) |
| 2167 |
< |
return e.find(h, k); |
| 2168 |
< |
} while ((e = e.next) != null); |
| 2166 |
> |
if (eh < 0) { |
| 2167 |
> |
if (e instanceof ForwardingNode) { |
| 2168 |
> |
tab = ((ForwardingNode<K,V>)e).nextTable; |
| 2169 |
> |
continue outer; |
| 2170 |
> |
} |
| 2171 |
> |
else |
| 2172 |
> |
return e.find(h, k); |
| 2173 |
> |
} |
| 2174 |
> |
if ((e = e.next) == null) |
| 2175 |
> |
return null; |
| 2176 |
> |
} |
| 2177 |
|
} |
| 2156 |
– |
return null; |
| 2178 |
|
} |
| 2179 |
|
} |
| 2180 |
|
|
| 2348 |
|
int nextn = nextTab.length; |
| 2349 |
|
ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab); |
| 2350 |
|
boolean advance = true; |
| 2351 |
+ |
boolean finishing = false; // to ensure sweep before committing nextTab |
| 2352 |
|
for (int i = 0, bound = 0;;) { |
| 2353 |
|
int nextIndex, nextBound, fh; Node<K,V> f; |
| 2354 |
|
while (advance) { |
| 2355 |
< |
if (--i >= bound) |
| 2355 |
> |
if (--i >= bound || finishing) |
| 2356 |
|
advance = false; |
| 2357 |
|
else if ((nextIndex = transferIndex) <= transferOrigin) { |
| 2358 |
|
i = -1; |
| 2368 |
|
} |
| 2369 |
|
} |
| 2370 |
|
if (i < 0 || i >= n || i + n >= nextn) { |
| 2371 |
+ |
if (finishing) { |
| 2372 |
+ |
nextTable = null; |
| 2373 |
+ |
table = nextTab; |
| 2374 |
+ |
sizeCtl = (n << 1) - (n >>> 1); |
| 2375 |
+ |
return; |
| 2376 |
+ |
} |
| 2377 |
|
for (int sc;;) { |
| 2378 |
|
if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) { |
| 2379 |
< |
if (sc == -1) { |
| 2380 |
< |
nextTable = null; |
| 2381 |
< |
table = nextTab; |
| 2382 |
< |
sizeCtl = (n << 1) - (n >>> 1); |
| 2383 |
< |
} |
| 2356 |
< |
return; |
| 2379 |
> |
if (sc != -1) |
| 2380 |
> |
return; |
| 2381 |
> |
finishing = advance = true; |
| 2382 |
> |
i = n; // recheck before commit |
| 2383 |
> |
break; |
| 2384 |
|
} |
| 2385 |
|
} |
| 2386 |
|
} |
| 2422 |
|
else |
| 2423 |
|
hn = new Node<K,V>(ph, pk, pv, hn); |
| 2424 |
|
} |
| 2425 |
+ |
setTabAt(nextTab, i, ln); |
| 2426 |
+ |
setTabAt(nextTab, i + n, hn); |
| 2427 |
+ |
setTabAt(tab, i, fwd); |
| 2428 |
+ |
advance = true; |
| 2429 |
|
} |
| 2430 |
|
else if (f instanceof TreeBin) { |
| 2431 |
|
TreeBin<K,V> t = (TreeBin<K,V>)f; |
| 2457 |
|
(hc != 0) ? new TreeBin<K,V>(lo) : t; |
| 2458 |
|
hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) : |
| 2459 |
|
(lc != 0) ? new TreeBin<K,V>(hi) : t; |
| 2460 |
+ |
setTabAt(nextTab, i, ln); |
| 2461 |
+ |
setTabAt(nextTab, i + n, hn); |
| 2462 |
+ |
setTabAt(tab, i, fwd); |
| 2463 |
+ |
advance = true; |
| 2464 |
|
} |
| 2430 |
– |
else |
| 2431 |
– |
ln = hn = null; |
| 2432 |
– |
setTabAt(nextTab, i, ln); |
| 2433 |
– |
setTabAt(nextTab, i + n, hn); |
| 2434 |
– |
setTabAt(tab, i, fwd); |
| 2435 |
– |
advance = true; |
| 2465 |
|
} |
| 2466 |
|
} |
| 2467 |
|
} |
| 2482 |
|
U.compareAndSwapInt(this, SIZECTL, sc, -2)) |
| 2483 |
|
transfer(tab, null); |
| 2484 |
|
} |
| 2485 |
< |
else if ((b = tabAt(tab, index)) != null) { |
| 2485 |
> |
else if ((b = tabAt(tab, index)) != null && b.hash >= 0) { |
| 2486 |
|
synchronized (b) { |
| 2487 |
|
if (tabAt(tab, index) == b) { |
| 2488 |
|
TreeNode<K,V> hd = null, tl = null; |
| 2557 |
|
p = pr; |
| 2558 |
|
else if ((pk = p.key) == k || (pk != null && k.equals(pk))) |
| 2559 |
|
return p; |
| 2560 |
< |
else if (pl == null && pr == null) |
| 2561 |
< |
break; |
| 2560 |
> |
else if (pl == null) |
| 2561 |
> |
p = pr; |
| 2562 |
> |
else if (pr == null) |
| 2563 |
> |
p = pl; |
| 2564 |
|
else if ((kc != null || |
| 2565 |
|
(kc = comparableClassFor(k)) != null) && |
| 2566 |
|
(dir = compareComparables(kc, k, pk)) != 0) |
| 2567 |
|
p = (dir < 0) ? pl : pr; |
| 2568 |
< |
else if (pl == null) |
| 2538 |
< |
p = pr; |
| 2539 |
< |
else if (pr == null || |
| 2540 |
< |
(q = pr.findTreeNode(h, k, kc)) == null) |
| 2541 |
< |
p = pl; |
| 2542 |
< |
else |
| 2568 |
> |
else if ((q = pr.findTreeNode(h, k, kc)) != null) |
| 2569 |
|
return q; |
| 2570 |
+ |
else |
| 2571 |
+ |
p = pl; |
| 2572 |
|
} while (p != null); |
| 2573 |
|
} |
| 2574 |
|
return null; |
| 2595 |
|
static final int READER = 4; // increment value for setting read lock |
| 2596 |
|
|
| 2597 |
|
/** |
| 2598 |
+ |
* Tie-breaking utility for ordering insertions when equal |
| 2599 |
+ |
* hashCodes and non-comparable. We don't require a total |
| 2600 |
+ |
* order, just a consistent insertion rule to maintain |
| 2601 |
+ |
* equivalence across rebalancings. Tie-breaking further than |
| 2602 |
+ |
* necessary simplifies testing a bit. |
| 2603 |
+ |
*/ |
| 2604 |
+ |
static int tieBreakOrder(Object a, Object b) { |
| 2605 |
+ |
int d; |
| 2606 |
+ |
if (a == null || b == null || |
| 2607 |
+ |
(d = a.getClass().getName(). |
| 2608 |
+ |
compareTo(b.getClass().getName())) == 0) |
| 2609 |
+ |
d = (System.identityHashCode(a) <= System.identityHashCode(b) ? |
| 2610 |
+ |
-1 : 1); |
| 2611 |
+ |
return d; |
| 2612 |
+ |
} |
| 2613 |
+ |
|
| 2614 |
+ |
/** |
| 2615 |
|
* Creates bin with initial set of nodes headed by b. |
| 2616 |
|
*/ |
| 2617 |
|
TreeBin(TreeNode<K,V> b) { |
| 2627 |
|
r = x; |
| 2628 |
|
} |
| 2629 |
|
else { |
| 2630 |
< |
Object key = x.key; |
| 2631 |
< |
int hash = x.hash; |
| 2630 |
> |
K k = x.key; |
| 2631 |
> |
int h = x.hash; |
| 2632 |
|
Class<?> kc = null; |
| 2633 |
|
for (TreeNode<K,V> p = r;;) { |
| 2634 |
|
int dir, ph; |
| 2635 |
< |
if ((ph = p.hash) > hash) |
| 2635 |
> |
K pk = p.key; |
| 2636 |
> |
if ((ph = p.hash) > h) |
| 2637 |
|
dir = -1; |
| 2638 |
< |
else if (ph < hash) |
| 2638 |
> |
else if (ph < h) |
| 2639 |
|
dir = 1; |
| 2640 |
< |
else if ((kc != null || |
| 2641 |
< |
(kc = comparableClassFor(key)) != null)) |
| 2642 |
< |
dir = compareComparables(kc, key, p.key); |
| 2643 |
< |
else |
| 2644 |
< |
dir = 0; |
| 2599 |
< |
TreeNode<K,V> xp = p; |
| 2640 |
> |
else if ((kc == null && |
| 2641 |
> |
(kc = comparableClassFor(k)) == null) || |
| 2642 |
> |
(dir = compareComparables(kc, k, pk)) == 0) |
| 2643 |
> |
dir = tieBreakOrder(k, pk); |
| 2644 |
> |
TreeNode<K,V> xp = p; |
| 2645 |
|
if ((p = (dir <= 0) ? p.left : p.right) == null) { |
| 2646 |
|
x.parent = xp; |
| 2647 |
|
if (dir <= 0) |
| 2655 |
|
} |
| 2656 |
|
} |
| 2657 |
|
this.root = r; |
| 2658 |
+ |
assert checkInvariants(root); |
| 2659 |
|
} |
| 2660 |
|
|
| 2661 |
|
/** |
| 2686 |
|
return; |
| 2687 |
|
} |
| 2688 |
|
} |
| 2689 |
< |
else if ((s | WAITER) == 0) { |
| 2689 |
> |
else if ((s & WAITER) == 0) { |
| 2690 |
|
if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) { |
| 2691 |
|
waiting = true; |
| 2692 |
|
waiter = Thread.currentThread(); |
| 2702 |
|
* using tree comparisons from root, but continues linear |
| 2703 |
|
* search when lock not available. |
| 2704 |
|
*/ |
| 2705 |
< |
final Node<K,V> find(int h, Object k) { |
| 2705 |
> |
final Node<K,V> find(int h, Object k) { |
| 2706 |
|
if (k != null) { |
| 2707 |
|
for (Node<K,V> e = first; e != null; e = e.next) { |
| 2708 |
|
int s; K ek; |
| 2739 |
|
*/ |
| 2740 |
|
final TreeNode<K,V> putTreeVal(int h, K k, V v) { |
| 2741 |
|
Class<?> kc = null; |
| 2742 |
+ |
boolean searched = false; |
| 2743 |
|
for (TreeNode<K,V> p = root;;) { |
| 2744 |
< |
int dir, ph; K pk; TreeNode<K,V> q, pr; |
| 2744 |
> |
int dir, ph; K pk; |
| 2745 |
|
if (p == null) { |
| 2746 |
|
first = root = new TreeNode<K,V>(h, k, v, null, null); |
| 2747 |
|
break; |
| 2755 |
|
else if ((kc == null && |
| 2756 |
|
(kc = comparableClassFor(k)) == null) || |
| 2757 |
|
(dir = compareComparables(kc, k, pk)) == 0) { |
| 2758 |
< |
if (p.left == null) |
| 2759 |
< |
dir = 1; |
| 2760 |
< |
else if ((pr = p.right) == null || |
| 2761 |
< |
(q = pr.findTreeNode(h, k, kc)) == null) |
| 2762 |
< |
dir = -1; |
| 2763 |
< |
else |
| 2764 |
< |
return q; |
| 2758 |
> |
if (!searched) { |
| 2759 |
> |
TreeNode<K,V> q, ch; |
| 2760 |
> |
searched = true; |
| 2761 |
> |
if (((ch = p.left) != null && |
| 2762 |
> |
(q = ch.findTreeNode(h, k, kc)) != null) || |
| 2763 |
> |
((ch = p.right) != null && |
| 2764 |
> |
(q = ch.findTreeNode(h, k, kc)) != null)) |
| 2765 |
> |
return q; |
| 2766 |
> |
} |
| 2767 |
> |
dir = tieBreakOrder(k, pk); |
| 2768 |
|
} |
| 2769 |
+ |
|
| 2770 |
|
TreeNode<K,V> xp = p; |
| 2771 |
< |
if ((p = (dir < 0) ? p.left : p.right) == null) { |
| 2771 |
> |
if ((p = (dir <= 0) ? p.left : p.right) == null) { |
| 2772 |
|
TreeNode<K,V> x, f = first; |
| 2773 |
|
first = x = new TreeNode<K,V>(h, k, v, f, xp); |
| 2774 |
|
if (f != null) |
| 2775 |
|
f.prev = x; |
| 2776 |
< |
if (dir < 0) |
| 2776 |
> |
if (dir <= 0) |
| 2777 |
|
xp.left = x; |
| 2778 |
|
else |
| 2779 |
|
xp.right = x; |
