1 files changed, 88 insertions, 0 deletions
diff --git a/framework/src/onos/utils/misc/src/main/java/org/onlab/util/GroupedThreadFactory.java b/framework/src/onos/utils/misc/src/main/java/org/onlab/util/GroupedThreadFactory.java
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--- /dev/null
+++ b/framework/src/onos/utils/misc/src/main/java/org/onlab/util/GroupedThreadFactory.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed 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.onlab.util;
+
+import org.apache.commons.lang3.concurrent.ConcurrentUtils;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ThreadFactory;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * Thread factory for creating threads that belong to the specified thread group.
+ */
+public final class GroupedThreadFactory implements ThreadFactory {
+
+    public static final String DELIMITER = "/";
+
+    private final ThreadGroup group;
+
+    // Cache of created thread factories.
+    private static final ConcurrentHashMap<String, GroupedThreadFactory> FACTORIES =
+            new ConcurrentHashMap<>();
+
+    /**
+     * Returns thread factory for producing threads associated with the specified
+     * group name. The group name-space is hierarchical, based on slash-delimited
+     * name segments, e.g. {@code onos/intent}.
+     *
+     * @param groupName group name
+     * @return thread factory
+     */
+    public static GroupedThreadFactory groupedThreadFactory(String groupName) {
+        GroupedThreadFactory factory = FACTORIES.get(groupName);
+        if (factory != null) {
+            return factory;
+        }
+
+        // Find the parent group or root the group hierarchy under default group.
+        int i = groupName.lastIndexOf(DELIMITER);
+        if (i > 0) {
+            String name = groupName.substring(0, i);
+            ThreadGroup parentGroup = groupedThreadFactory(name).threadGroup();
+            factory = new GroupedThreadFactory(new ThreadGroup(parentGroup, groupName));
+        } else {
+            factory = new GroupedThreadFactory(new ThreadGroup(groupName));
+        }
+
+        return ConcurrentUtils.putIfAbsent(FACTORIES, groupName, factory);
+    }
+
+    // Creates a new thread group
+    private GroupedThreadFactory(ThreadGroup group) {
+        this.group = group;
+    }
+
+    /**
+     * Returns the thread group associated with the factory.
+     *
+     * @return thread group
+     */
+    public ThreadGroup threadGroup() {
+        return group;
+    }
+
+    @Override
+    public Thread newThread(Runnable r) {
+        return new Thread(group, r);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this).add("group", group).toString();
+    }
+}