Fixes openshift#282

possibly avoids duplicate build entries in the skip list by indexing off of build name vs. obj
synchronizes on the flush method since it possible can get called by multiple folks

src/main/java/io/fabric8/jenkins/openshiftsync/BuildWatcher.java

@@ -28,7 +28,6 @@
 import jenkins.security.NotReallyRoleSensitiveCallable;
 
 import org.apache.commons.lang.StringUtils;
-import org.eclipse.jetty.util.ConcurrentHashSet;
 import org.jenkinsci.plugins.workflow.job.WorkflowJob;
 import org.jenkinsci.plugins.workflow.job.WorkflowRun;
 
@@ -40,6 +39,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -66,17 +66,17 @@ public class BuildWatcher extends BaseWatcher {
     private static final Logger logger = Logger.getLogger(BuildWatcher.class
             .getName());
 
-    // the fabric8 classes like Build have equal/hashcode annotations that
-    // should allow
-    // us to index via the objects themselves;
     // now that listing interval is 5 minutes (used to be 10 seconds), we have
     // seen
     // timing windows where if the build watch events come before build config
     // watch events
     // when both are created in a simultaneous fashion, there is an up to 5
     // minute delay
     // before the job run gets kicked off
-    private static final ConcurrentHashSet<Build> buildsWithNoBCList = new ConcurrentHashSet<>();
+    // started seeing duplicate builds getting kicked off so quit depending on
+    // so moved off of concurrent hash set to concurrent hash map using 
+    // namepace/name key
+    private static final ConcurrentHashMap<String,Build> buildsWithNoBCList = new ConcurrentHashMap<String,Build>();
 
     @SuppressFBWarnings("EI_EXPOSE_REP2")
     public BuildWatcher(String[] namespaces) {
@@ -355,7 +355,7 @@ private static void addBuildToNoBCList(Build build) {
         if (!OpenShiftUtils.isPipelineStrategyBuild(build))
             return;
         try {
-          buildsWithNoBCList.add(build);
+          buildsWithNoBCList.put(build.getMetadata().getNamespace()+build.getMetadata().getName(), build);
         } catch (ConcurrentModificationException | IllegalArgumentException |
           UnsupportedOperationException | NullPointerException e) {
           logger.log(Level.WARNING,"Failed to add item " +
@@ -364,14 +364,14 @@ private static void addBuildToNoBCList(Build build) {
     }
 
     private static void removeBuildFromNoBCList(Build build) {
-          buildsWithNoBCList.remove(build);
+          buildsWithNoBCList.remove(build.getMetadata().getNamespace()+build.getMetadata().getName());
     }
 
     // trigger any builds whose watch events arrived before the
     // corresponding build config watch events
-    public static void flushBuildsWithNoBCList() {
+    public synchronized static void flushBuildsWithNoBCList() {
         boolean anyRemoveFailures = false;
-        for (Build build : buildsWithNoBCList) {
+        for (Build build : buildsWithNoBCList.values()) {
           WorkflowJob job = getJobFromBuild(build);
           if (job != null) {
             try {