[ONOS-4687] GoldenEye - Label map download issues.

Change-Id: I5b56ccc6b8bad3c585f4d33ddd6d9094751c8797
diff --git a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/SrpIdGenerators.java b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/SrpIdGenerators.java
new file mode 100644
index 0000000..e0cb3b3
--- /dev/null
+++ b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/SrpIdGenerators.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2015-present 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.onosproject.pcep.controller;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.slf4j.Logger;
+
+/**
+ * Unique Srp Id generator for pcep messages.
+ */
+public final class SrpIdGenerators {
+
+    private static final Logger log = getLogger(SrpIdGenerators.class);
+    private static final AtomicInteger SRP_ID_GEN = new AtomicInteger();
+    private static final int MAX_SRP_ID = 0x7FFFFFFF;
+    private static int srpId;
+
+    /**
+     * Default constructor.
+     */
+    private SrpIdGenerators() {
+    }
+
+    /**
+     * Get the next srp id.
+     *
+     * @return srp id
+     */
+    public static int create() {
+        do {
+            if (srpId >= MAX_SRP_ID) {
+                if (SRP_ID_GEN.get() >= MAX_SRP_ID) {
+                    SRP_ID_GEN.set(0);
+                }
+            }
+            srpId = SRP_ID_GEN.incrementAndGet();
+        } while (srpId > MAX_SRP_ID);
+        return srpId;
+    }
+}