Adding Concurrency in Pool Manager (#1698)

Concurrency in the pool manager allows specializing pods concurrently based on a specified limit. 

Co-authored-by: Vishal <vishal-biyani@users.noreply.github.com>

pkg/executor/executor.go

@@ -99,6 +99,31 @@ func (executor *Executor) serveCreateFuncServices() {
 		req := <-executor.requestChan
 		fnMetadata := &req.function.ObjectMeta
 
+		if req.function.Spec.InvokeStrategy.ExecutionStrategy.ExecutorType == fv1.ExecutorTypePoolmgr {
+			go func() {
+				buffer := 10 // add some buffer time for specialization
+				specializationTimeout := req.function.Spec.InvokeStrategy.ExecutionStrategy.SpecializationTimeout
+
+				// set minimum specialization timeout to avoid illegal input and
+				// compatibility problem when applying old spec file that doesn't
+				// have specialization timeout field.
+				if specializationTimeout < fv1.DefaultSpecializationTimeOut {
+					specializationTimeout = fv1.DefaultSpecializationTimeOut
+				}
+
+				fnSpecializationTimeoutContext, cancel := context.WithTimeout(context.Background(),
+					time.Duration(specializationTimeout+buffer)*time.Second)
+				defer cancel()
+
+				fsvc, err := executor.createServiceForFunction(fnSpecializationTimeoutContext, req.function)
+				req.respChan <- &createFuncServiceResponse{
+					funcSvc: fsvc,
+					err:     err,
+				}
+			}()
+			continue
+		}
+
 		// Cache miss -- is this first one to request the func?
 		wg, found := executor.fsCreateWg[crd.CacheKey(fnMetadata)]
 		if !found {