Avoiding initialization of multiple processes when a WebHost channel is avaialable and worker indexing is enabled (#8805) (#8811)

Co-authored-by: Fabio Cavalcante <[email protected]>

Author: VpOfEngineering

src/WebJobs.Script.Grpc/Channel/GrpcWorkerChannel.cs

@@ -478,6 +478,7 @@ internal FunctionLoadRequestCollection GetFunctionLoadRequestCollection(IEnumera
 
         public Task SendFunctionEnvironmentReloadRequest()
         {
+            _functionsIndexingTask = new TaskCompletionSource<List<RawFunctionMetadata>>(TaskCreationOptions.RunContinuationsAsynchronously);
             _workerChannelLogger.LogDebug("Sending FunctionEnvironmentReloadRequest to WorkerProcess with Pid: '{0}'", _rpcWorkerProcess.Id);
             IDisposable latencyEvent = _metricsLogger.LatencyEvent(MetricEventNames.SpecializationEnvironmentReloadRequestResponse);
 

src/WebJobs.Script/Workers/Rpc/FunctionRegistration/RpcFunctionInvocationDispatcher.cs

@@ -326,7 +326,7 @@ public async Task InitializeAsync(IEnumerable<FunctionMetadata> functions, Cance
                 Dictionary<string, TaskCompletionSource<IRpcWorkerChannel>> webhostLanguageWorkerChannels = _webHostLanguageWorkerChannelManager.GetChannels(_workerRuntime);
                 if (webhostLanguageWorkerChannels != null)
                 {
-                    int countOfReadyChannels = 0;
+                    int workerProcessCount = 0;
                     foreach (string workerId in webhostLanguageWorkerChannels.Keys.ToList())
                     {
                         if (webhostLanguageWorkerChannels.TryGetValue(workerId, out TaskCompletionSource<IRpcWorkerChannel> initializedLanguageWorkerChannelTask))
@@ -341,8 +341,9 @@ public async Task InitializeAsync(IEnumerable<FunctionMetadata> functions, Cance
                                 {
                                     initializedLanguageWorkerChannel.SetupFunctionInvocationBuffers(_functions);
                                     initializedLanguageWorkerChannel.SendFunctionLoadRequests(_managedDependencyOptions.Value, _scriptOptions.FunctionTimeout);
-                                    ++countOfReadyChannels;
                                 }
+
+                                ++workerProcessCount;
                             }
                             catch (Exception ex)
                             {
@@ -351,7 +352,7 @@ public async Task InitializeAsync(IEnumerable<FunctionMetadata> functions, Cance
                             }
                         }
                     }
-                    StartWorkerProcesses(countOfReadyChannels, InitializeWebhostLanguageWorkerChannel, true, _webHostLanguageWorkerChannelManager.GetChannels(_workerRuntime));
+                    StartWorkerProcesses(workerProcessCount, InitializeWebhostLanguageWorkerChannel, true, _webHostLanguageWorkerChannelManager.GetChannels(_workerRuntime));
                 }
                 else
                 {