Issue #1861 - Limit total bytes pooled by ByteBufferPools.

Fixed the implementation to correctly track the memory retained.

Signed-off-by: Simone Bordet <simone.bordet@gmail.com>

jetty-io/src/main/java/org/eclipse/jetty/io/AbstractByteBufferPool.java

@@ -64,13 +64,11 @@ abstract class AbstractByteBufferPool implements ByteBufferPool
         int capacity = buffer.capacity();
         long maxMemory = direct ? _maxDirectMemory : _maxHeapMemory;
         AtomicLong memory = direct ? _directMemory : _heapMemory;
-        if (maxMemory <= 0)
-            return true;
         while (true)
         {
             long current = memory.get();
             long value = current + capacity;
-            if (value > maxMemory)
+            if (maxMemory > 0 && value > maxMemory)
                 return false;
             if (memory.compareAndSet(current, value))
                 return true;

jetty-io/src/main/java/org/eclipse/jetty/io/ArrayByteBufferPool.java

@@ -100,13 +100,13 @@ public class ArrayByteBufferPool extends AbstractByteBufferPool
     @Override
     public ByteBuffer acquire(int size, boolean direct)
     {
+        int capacity = size < _minCapacity ? size : (bucketFor(size) + 1) * getCapacityFactor();
         ByteBufferPool.Bucket bucket = bucketFor(size, direct, null);
         if (bucket == null)
-        {
-            int capacity = size < _minCapacity ? size : (bucketFor(size) + 1) * getCapacityFactor();
             return newByteBuffer(capacity, direct);
-        }
-        ByteBuffer buffer = bucket.acquire(direct);
+        ByteBuffer buffer = bucket.acquire();
+        if (buffer == null)
+            return newByteBuffer(capacity, direct);
         decrementMemory(buffer);
         return buffer;
     }

jetty-io/src/main/java/org/eclipse/jetty/io/ByteBufferPool.java

@@ -145,6 +145,22 @@ public interface ByteBufferPool
             _space = maxSize > 0 ? new AtomicInteger(maxSize) : null;
         }
 
+        public ByteBuffer acquire()
+        {
+            ByteBuffer buffer = queuePoll();
+            if (buffer == null)
+                return null;
+            if (_space != null)
+                _space.incrementAndGet();
+            return buffer;
+        }
+
+        /**
+         * @param direct whether to create a direct buffer when none is available
+         * @return a ByteBuffer
+         * @deprecated use {@link #acquire()} instead
+         */
+        @Deprecated
         public ByteBuffer acquire(boolean direct)
         {
             ByteBuffer buffer = queuePoll();

jetty-io/src/main/java/org/eclipse/jetty/io/MappedByteBufferPool.java

@@ -105,11 +105,14 @@ public class MappedByteBufferPool extends AbstractByteBufferPool
     public ByteBuffer acquire(int size, boolean direct)
     {
         int b = bucketFor(size);
+        int capacity = b * getCapacityFactor();
         ConcurrentMap<Integer, Bucket> buffers = bucketsFor(direct);
         Bucket bucket = buffers.get(b);
         if (bucket == null)
-            return newByteBuffer(b * getCapacityFactor(), direct);
-        ByteBuffer buffer = bucket.acquire(direct);
+            return newByteBuffer(capacity, direct);
+        ByteBuffer buffer = bucket.acquire();
+        if (buffer == null)
+            return newByteBuffer(capacity, direct);
         decrementMemory(buffer);
         return buffer;
     }