Plasma Memory Manager Implementation (apache#56)

core/src/main/java/org/apache/spark/io/pmem/PlasmaMemoryManager.java

@@ -0,0 +1,53 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.spark.io.pmem;
+
+import com.google.common.annotations.VisibleForTesting;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * PMem Memory Manager
+ * Handle whether the system can provide enough pmem memory in numeric
+ */
+public class PlasmaMemoryManager {
+
+  private long totalMemory;
+  @VisibleForTesting
+  AtomicLong memoryUsed = new AtomicLong(0);
+
+  private double useRatio;
+
+  public PlasmaMemoryManager(long totalMemory, double useRatio) {
+    this.totalMemory = totalMemory;
+    this.useRatio = useRatio;
+  }
+
+  // Make pmem can be written when usage is lower than use ratio
+  public boolean isAvailable() {
+    return (totalMemory * useRatio - memoryUsed.get()) > 0;
+  }
+
+  public void increase(long memorySize) {
+    memoryUsed.getAndAdd(memorySize);
+  }
+
+  public void release(long memorySize) {
+    memoryUsed.getAndAdd(memorySize * -1);
+  }
+
+}

core/src/test/java/org/apache/spark/io/pmem/PlasmaMemoryManagerSuite.java

@@ -0,0 +1,45 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.spark.io.pmem;
+
+import org.junit.Test;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.*;
+
+public class PlasmaMemoryManagerSuite {
+
+  @Test
+  public void testMultiThreadUseCase() throws InterruptedException {
+    PlasmaMemoryManager memoryManager = new PlasmaMemoryManager(100000000, 0.8);
+    int processNum = Runtime.getRuntime().availableProcessors();
+    ExecutorService threadPool = Executors.newFixedThreadPool(processNum);
+    for (int i = 0; i < 100 * processNum; i++) {
+      threadPool.submit(() -> {
+        memoryManager.increase(100);
+        memoryManager.release(100);
+      });
+    }
+    threadPool.shutdown();
+    threadPool.awaitTermination(Long.MAX_VALUE, TimeUnit.MINUTES);
+    assertEquals(0, memoryManager.memoryUsed.get());
+  }
+
+}

core/src/test/java/org/apache/spark/io/pmem/PlasmaOutputInputStreamSuite.java

@@ -1,3 +1,19 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.apache.spark.io.pmem;
 
 import org.apache.spark.SparkConf;