fix wrapping when stream id is 0

robertroeser · robertroeser · commit f29ff85f44bb · 2019-07-24T01:16:47.000-07:00
Signed-off-by: Robert Roeser &lt;rroeserr@gmail.com&gt;
diff --git a/rsocket-core/src/jmh/java/io/rsocket/StreamIdSupplierPerf.java b/rsocket-core/src/jmh/java/io/rsocket/StreamIdSupplierPerf.java
@@ -0,0 +1,35 @@
+package io.rsocket;
+
+import io.netty.util.collection.IntObjectMap;
+import io.rsocket.internal.SynchronizedIntObjectHashMap;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Blackhole;
+
+@BenchmarkMode(Mode.Throughput)
+@Fork(
+    value = 1 // , jvmArgsAppend = {"-Dio.netty.leakDetection.level=advanced"}
+    )
+@Warmup(iterations = 10)
+@Measurement(iterations = 10)
+@State(Scope.Thread)
+public class StreamIdSupplierPerf {
+  @Benchmark
+  public void benchmarkStreamId(Input input) {
+    int i = input.supplier.nextStreamId(input.map);
+    input.bh.consume(i);
+  }
+
+  @State(Scope.Benchmark)
+  public static class Input {
+    Blackhole bh;
+    IntObjectMap map;
+    StreamIdSupplier supplier;
+
+    @Setup
+    public void setup(Blackhole bh) {
+      this.supplier = StreamIdSupplier.clientSupplier();
+      this.bh = bh;
+      this.map = new SynchronizedIntObjectHashMap();
+    }
+  }
+}
diff --git a/rsocket-core/src/main/java/io/rsocket/StreamIdSupplier.java b/rsocket-core/src/main/java/io/rsocket/StreamIdSupplier.java
@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package io.rsocket;
 
 import io.netty.util.collection.IntObjectMap;
@@ -43,7 +42,7 @@ int nextStreamId(IntObjectMap<?> streamIds) {
     int streamId;
     do {
       streamId = (int) STREAM_ID.addAndGet(this, 2) & MASK;
-    } while (streamIds.containsKey(streamId));
+    } while (streamId == 0 || streamIds.containsKey(streamId));
     return streamId;
   }
 
diff --git a/rsocket-core/src/test/java/io/rsocket/StreamIdSupplierTest.java b/rsocket-core/src/test/java/io/rsocket/StreamIdSupplierTest.java
@@ -95,8 +95,8 @@ public void testWrap() {
     StreamIdSupplier s = new StreamIdSupplier(Integer.MAX_VALUE - 3);
 
     assertEquals(2147483646, s.nextStreamId(map));
-    assertEquals(0, s.nextStreamId(map));
     assertEquals(2, s.nextStreamId(map));
+    assertEquals(4, s.nextStreamId(map));
 
     s = new StreamIdSupplier(Integer.MAX_VALUE - 2);
 
