Fix for unit test failure when threads are created too slowly.

test/AtomicIntegerConcurrentTest.java

@@ -5,7 +5,7 @@ public class AtomicIntegerConcurrentTest {
                               final int threadCount, 
                               final int iterationsPerThread) {
     // we assume a 1ms delay per thread to try to get them all to start at the same time
-    final long startTime = System.currentTimeMillis() + threadCount;
+    final long startTime = System.currentTimeMillis() + threadCount + 10;
     final AtomicInteger result = new AtomicInteger();
     final AtomicInteger threadDoneCount = new AtomicInteger();
     
@@ -15,6 +15,7 @@ public class AtomicIntegerConcurrentTest {
         public void run() {
           try {
             doOperation();
+            waitTillReady();
           } finally {
             synchronized (threadDoneCount) {
               threadDoneCount.incrementAndGet();
@@ -24,15 +25,19 @@ public class AtomicIntegerConcurrentTest {
           }
         }
         
-        private void doOperation() {
+        private void waitTillReady() {
           long sleepTime = System.currentTimeMillis() - startTime;
+          if (sleepTime > 0) {
             try {
               Thread.sleep(sleepTime);
             } catch (InterruptedException e) {
               // let thread exit
               return;
             }
+          }
+        }
         
+        private void doOperation() {
           boolean flip = true;
           for (int i = 0; i < iterationsPerThread; i++) {
             if (flip) {

test/AtomicLongConcurrentTest.java

@@ -5,7 +5,7 @@ public class AtomicLongConcurrentTest {
                               final int threadCount, 
                               final int iterationsPerThread) {
     // we assume a 1ms delay per thread to try to get them all to start at the same time
-    final long startTime = System.currentTimeMillis() + threadCount;
+    final long startTime = System.currentTimeMillis() + threadCount + 10;
     final AtomicLong result = new AtomicLong();
     final AtomicLong threadDoneCount = new AtomicLong();
     
@@ -15,6 +15,7 @@ public class AtomicLongConcurrentTest {
         public void run() {
           try {
             doOperation();
+            waitTillReady();
           } finally {
             synchronized (threadDoneCount) {
               threadDoneCount.incrementAndGet();
@@ -24,15 +25,19 @@ public class AtomicLongConcurrentTest {
           }
         }
         
-        private void doOperation() {
+        private void waitTillReady() {
           long sleepTime = System.currentTimeMillis() - startTime;
+          if (sleepTime > 0) {
             try {
               Thread.sleep(sleepTime);
             } catch (InterruptedException e) {
               // let thread exit
               return;
             }
+          }
+        }
         
+        private void doOperation() {
           boolean flip = true;
           for (int i = 0; i < iterationsPerThread; i++) {
             if (flip) {

test/AtomicReferenceConcurrentTest.java

@@ -5,7 +5,7 @@ public class AtomicReferenceConcurrentTest {
   private static void runTest(final int threadCount, 
                               final int iterationsPerThread) {
     // we assume a 1ms delay per thread to try to get them all to start at the same time
-    final long startTime = System.currentTimeMillis() + threadCount;
+    final long startTime = System.currentTimeMillis() + threadCount + 10;
     final AtomicReference<Integer> result = new AtomicReference<Integer>(0);
     final AtomicInteger threadDoneCount = new AtomicInteger(0);
     
@@ -15,6 +15,7 @@ public class AtomicReferenceConcurrentTest {
         public void run() {
           try {
             doOperation();
+            waitTillReady();
           } finally {
             synchronized (threadDoneCount) {
               threadDoneCount.incrementAndGet();
@@ -24,15 +25,19 @@ public class AtomicReferenceConcurrentTest {
           }
         }
         
-        private void doOperation() {
+        private void waitTillReady() {
           long sleepTime = System.currentTimeMillis() - startTime;
+          if (sleepTime > 0) {
             try {
               Thread.sleep(sleepTime);
             } catch (InterruptedException e) {
               // let thread exit
               return;
             }
+          }
+        }
         
+        private void doOperation() {
           for (int i = 0; i < iterationsPerThread; i++) {
             Integer current = result.get();
             while (! result.compareAndSet(current, current + 1)) {
@@ -63,6 +68,5 @@ public class AtomicReferenceConcurrentTest {
   
   public static void main(String[] args) {
     runTest(10, 100);
-    runTest(10, 100);
   }
 }