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Commit 94ce568

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author
someone-1
committed
addded locks
1 parent 1515583 commit 94ce568

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4 files changed

+102
-58
lines changed

4 files changed

+102
-58
lines changed

‎src/main/java/barrier/CountDownLatch.java‎

Lines changed: 0 additions & 21 deletions
This file was deleted.
Lines changed: 37 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,37 @@
1+
package barrier;
2+
3+
import java.util.concurrent.locks.Lock;
4+
import java.util.concurrent.locks.ReadWriteLock;
5+
import java.util.concurrent.locks.ReentrantReadWriteLock;
6+
7+
public class CountDownLatch {
8+
ReadWriteLock lock = new ReentrantReadWriteLock();
9+
private Lock rLock = lock.readLock();
10+
private Lock wLock = lock.writeLock();
11+
private int count;
12+
13+
14+
public CountDownLatch(int count){
15+
this.count = count;
16+
}
17+
18+
19+
public synchronized void countDown(){
20+
System.out.println(count + " -count in " + Thread.currentThread().getName());
21+
count--;
22+
this.notifyAll();
23+
}
24+
25+
26+
public int getCount(){
27+
return this.count;
28+
}
29+
30+
31+
public void await() throws InterruptedException {
32+
while (count > 0) {
33+
wait();
34+
}
35+
}
36+
37+
}

‎src/main/java/dataStructures/Hashmap.java‎

Lines changed: 60 additions & 36 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,8 @@
11
package dataStructures;
22

3+
import java.util.concurrent.locks.Lock;
4+
import java.util.concurrent.locks.ReentrantReadWriteLock;
5+
36
public class Hashmap <K, V>{
47

58
private int bucketCount = 16;
@@ -10,7 +13,7 @@ public void insert(K key, V val){
1013
Bucket<K, V> bucket;
1114
int ind = getIndex(key);
1215
if(buckets[ind] == null){
13-
bucket = new Bucket<K, V>();
16+
bucket = new Bucket<>();
1417
buckets[ind] = bucket;
1518
}else {
1619
bucket = buckets[ind];
@@ -30,6 +33,8 @@ public V get(K key){
3033
return node.val;
3134
}
3235

36+
// public void replace(K key, V oldVal, )
37+
3338
public V delete(K key){
3439
int ind = getIndex(key);
3540
if(buckets[ind] == null){
@@ -52,59 +57,78 @@ private int getIndex(K key){
5257
class Bucket<K, V>{
5358
private Node<K, V> start;
5459
private Node<K, V> end;
60+
private ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
61+
private Lock rLock = lock.readLock();
62+
private Lock wLock = lock.writeLock();
5563

5664
/*
5765
* adds new node if key is not present
5866
* updated value of node if key is present
5967
* */
60-
public void updNode(Node<K, V> node){
61-
if(start == null){
62-
start = node;
63-
end = node;
64-
return;
65-
}
66-
Node<K, V> oldNode = getNode(node.key);
67-
if(oldNode == null) {
68-
end.next = node;
69-
node.prev = end;
70-
end = node;
71-
return;
68+
void updNode(Node<K, V> node){
69+
wLock.lock();
70+
try {
71+
if (start == null) {
72+
start = node;
73+
end = node;
74+
return;
75+
}
76+
Node<K, V> oldNode = getNode(node.key);
77+
if (oldNode == null) {
78+
end.next = node;
79+
node.prev = end;
80+
end = node;
81+
return;
82+
}
83+
oldNode.val = node.val;
84+
}finally {
85+
wLock.unlock();
7286
}
73-
oldNode.val = node.val;
7487
}
7588

7689
/*
7790
* returns node if node.key.equals(key)
7891
* else returns null
7992
* */
80-
public Node<K,V> getNode(K key){
81-
Node<K,V> node = start;
82-
while (node != null){
83-
if(node.key.equals(key)){
84-
return node;
93+
Node<K,V> getNode(K key){
94+
rLock.lock();
95+
try {
96+
Node<K, V> node = start;
97+
while (node != null) {
98+
if (node.key.equals(key)) {
99+
return node;
100+
}
101+
node = node.next;
85102
}
86-
node = node.next;
103+
return null;
104+
}finally {
105+
rLock.unlock();
87106
}
88-
return null;
89107
}
90108

91109

92-
public Node<K, V> delNode(K key){
93-
Node<K,V> node = getNode(key);
94-
if(node != null){
95-
if (start == node){
96-
start = node.next;
97-
}
98-
if (end == node){
99-
end = node.prev;
100-
}
101-
Node<K, V> nxtNode = node.next;
102-
Node<K, V> prevNode = node.prev;
103-
if(prevNode != null){
104-
prevNode.next = nxtNode;
110+
Node<K, V> delNode(K key){
111+
wLock.lock();
112+
try {
113+
114+
Node<K, V> node = getNode(key);
115+
if (node != null) {
116+
if (start == node) {
117+
start = node.next;
118+
}
119+
if (end == node) {
120+
end = node.prev;
121+
}
122+
Node<K, V> nxtNode = node.next;
123+
Node<K, V> prevNode = node.prev;
124+
if (prevNode != null) {
125+
prevNode.next = nxtNode;
126+
}
105127
}
128+
return node;
129+
}finally {
130+
wLock.unlock();
106131
}
107-
return node;
108132
}
109133
}
110134

@@ -113,7 +137,7 @@ class Node<K, V>{
113137
Node<K, V> prev;
114138
K key;
115139
V val;
116-
publicNode(K key, V val){
140+
Node(K key, V val){
117141
this.val = val;
118142
this.key = key;
119143
next = null;

‎src/test/java/barrier/TestCountDownLatch.java‎ renamed to ‎src/test/java/barrier/TestFakeCountDownLatch.java‎

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -16,10 +16,12 @@ public void testCountDown() throws InterruptedException {
1616
latchSingleThread.countDown();
1717
latchSingleThread.countDown();
1818
Assertions.assertEquals(threadCount-2, latchSingleThread.getCount());
19+
20+
1921
CountDownLatch latch = new CountDownLatch(threadCount);
2022
java.util.concurrent.CountDownLatch realLatch = new
2123
java.util.concurrent.CountDownLatch(threadCount - diff);
22-
ExecutorService service = Executors.newFixedThreadPool(10);
24+
ExecutorService service = Executors.newFixedThreadPool(threadCount);
2325
for (int i = 0; i < threadCount; i++) {
2426
service.submit(() -> {
2527
try {
@@ -29,9 +31,11 @@ public void testCountDown() throws InterruptedException {
2931
}
3032
latch.countDown();
3133
realLatch.countDown();
34+
System.out.println(latch.getCount() + " - count " + threadCount);
3235
});
3336
}
3437
realLatch.await();
38+
latch.await();
3539
Assertions.assertEquals(diff, latch.getCount());
3640
}
3741

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