[WIFI-7888] Add concurrent burst config handling in opensync gateway

opensync-ext-interface/src/main/java/com/telecominfraproject/wlan/opensync/external/integration/OvsdbSession.java

@@ -1,5 +1,7 @@
 package com.telecominfraproject.wlan.opensync.external.integration;
 
+import java.util.concurrent.atomic.AtomicInteger;
+
 import com.vmware.ovsdb.service.OvsdbClient;
 
 public class OvsdbSession {
@@ -7,6 +9,7 @@ public class OvsdbSession {
     private String apId;
     private long routingId;
     private long equipmentId;
+    private AtomicInteger currentConfigNumInFlight = new AtomicInteger();
     
     public OvsdbClient getOvsdbClient() {
         return ovsdbClient;
@@ -33,4 +36,8 @@ public class OvsdbSession {
         this.equipmentId = equipmentId;
     }
     
+    public AtomicInteger getCurrentConfigNumInFlight() {
+        return currentConfigNumInFlight;
+    }
+ 
 }

opensync-gateway/src/main/java/com/telecominfraproject/wlan/opensync/ovsdb/TipWlanOvsdbClient.java

@@ -440,6 +440,13 @@ public class TipWlanOvsdbClient implements OvsdbClientInterface {
 
         OvsdbClient ovsdbClient = ovsdbSession.getOvsdbClient();
 
+        int currentConfigCount = ovsdbSession.getCurrentConfigNumInFlight().get();
+        if (currentConfigCount == 0L) {
+            // Current count is 0, start this config push
+            // Increment other incoming configs into the count until this config push is done
+            currentConfigCount = ovsdbSession.getCurrentConfigNumInFlight().incrementAndGet();
+            do {
+                try {
                     OpensyncAPConfig opensyncAPConfig = extIntegrationInterface.getApConfig(apId);
                     
                     if (opensyncAPConfig == null) {
@@ -461,8 +468,28 @@ public class TipWlanOvsdbClient implements OvsdbClientInterface {
                     if(needToPushConfigToAP) {
                         pushConfigToAp(ovsdbClient, opensyncAPConfig, apId, configVersionFromProfiles);
                     }
-        
                     LOG.debug("Finished processConfigChanged for {}", apId);
+                } catch (Exception ex) {
+                    // If anything fails in the ovsdb config push, clean up count and exit
+                    ovsdbSession.getCurrentConfigNumInFlight().set(0);
+                    return;
+                }
+                int checkCount = ovsdbSession.getCurrentConfigNumInFlight().get();
+                if (checkCount == currentConfigCount) {
+                    // Count didn't change from pre-config push, we can clean up and exit
+                    if (ovsdbSession.getCurrentConfigNumInFlight().compareAndSet(currentConfigCount, 0)) {
+                        return;
+                    }
+                } else {
+                    // Count has changed, update the currentConfigCount and rerun config push
+                    ovsdbSession.getCurrentConfigNumInFlight().incrementAndGet();
+                }
+            } while (ovsdbSession.getCurrentConfigNumInFlight().get() != 0);
+        } else {
+            // Count is not 0, another request is being processed for this OvsdbSession
+            // Remember this request, and the other thread will check the count when it's done
+            ovsdbSession.getCurrentConfigNumInFlight().incrementAndGet();
+        }
     }
 
     @Override