Fixed PoolSize and unit test

- Funny trap I made for myself.
- Integration tests detected the bug (jdbc_all)

Signed-off-by: David Matějček <david.matejcek@omnifish.ee>

appserver/connectors/connectors-runtime/pom.xml

@@ -166,6 +166,10 @@
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

appserver/connectors/connectors-runtime/src/main/java/com/sun/enterprise/resource/pool/PoolSize.java

@@ -66,7 +66,7 @@ public int getCurrentCount() {
      * @throws PoolingException if the current count already reached the capacity.
      */
     public void increment() throws PoolingException {
-        if (this.currentCount.getAndUpdate(v -> Math.max(v, this.capacity)) == this.capacity) {
+        if (this.currentCount.getAndUpdate(v -> Math.min(v + 1, this.capacity)) == this.capacity) {
             throw new PoolingException("Count of provided connections is already equal to the capacity (" + capacity
                 + ") therefore you cannot allocate any more resources.");
         }
@@ -78,7 +78,7 @@ public void increment() throws PoolingException {
      * If is already zero, doesn't do anything.
      */
     public void decrement() {
-        this.currentCount.getAndUpdate(v -> Math.min(v, 0));
+        this.currentCount.getAndUpdate(v -> Math.max(v - 1, 0));
     }
 
 

appserver/connectors/connectors-runtime/src/test/java/com/sun/enterprise/resource/pool/PoolSizeTest.java

@@ -29,6 +29,8 @@
 
 import org.junit.jupiter.api.Test;
 
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.greaterThan;
 import static org.junit.jupiter.api.Assertions.assertAll;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
@@ -42,19 +44,21 @@ public class PoolSizeTest {
 
     @Test
     void increaseAndDecrease() throws Exception {
-        PoolSize poolSize = new PoolSize(1);
-        assertEquals(1, poolSize.getCapacity());
-        poolSize.decrement();
-        assertEquals(0, poolSize.getCurrentCount());
+        PoolSize poolSize = new PoolSize(2);
+        assertEquals(2, poolSize.getCapacity());
         poolSize.increment();
         assertEquals(1, poolSize.getCurrentCount());
+        poolSize.increment();
+        assertEquals(2, poolSize.getCurrentCount());
         PoolingException e = assertThrows(PoolingException.class, () -> poolSize.increment());
         assertAll(
-            () -> assertEquals(1, poolSize.getCurrentCount()),
-            () -> assertEquals("Count of provided connections is already equal to the capacity (1) therefore"
+            () -> assertEquals(2, poolSize.getCurrentCount()),
+            () -> assertEquals("Count of provided connections is already equal to the capacity (2) therefore"
                 + " you cannot allocate any more resources.", e.getMessage())
         );
         poolSize.decrement();
+        assertEquals(1, poolSize.getCurrentCount());
+        poolSize.decrement();
         assertEquals(0, poolSize.getCurrentCount());
         poolSize.decrement();
         assertEquals(0, poolSize.getCurrentCount());
@@ -72,9 +76,11 @@ void threadSafety() throws Exception {
         for (int i = 0; i < taskCount; i++) {
             tasks.add(() -> {
                 poolSize.increment();
+                // increment succeeded
                 increases.incrementAndGet();
                 Thread.sleep(0, 10);
                 poolSize.decrement();
+                // if inc succeeded, dec must succeed too -> same count.
                 decreases.incrementAndGet();
                 return null;
             });
@@ -83,6 +89,7 @@ void threadSafety() throws Exception {
         assertAll(
             () -> assertTrue(futures.stream().allMatch(f -> f.isDone()), "All done."),
             () -> assertFalse(futures.stream().anyMatch(f -> f.isCancelled()), "None cancelled."),
+            () -> assertThat("Count of increases", increases.get(), greaterThan(poolSize.getCapacity())),
             () -> assertEquals(increases.get(), decreases.get(), "Count of increases and decreases"),
             () -> assertEquals(0, poolSize.getCurrentCount(), "Current count")
         );