ServiceWorker: Stop don't send a message before connection established

content/browser/service_worker/embedded_worker_instance.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/service_worker/embedded_worker_instance.h"
 
 #include <utility>
 
 #include "base/bind_helpers.h"
 #include "base/macros.h"
@@ skipping 477 matching lines @@
   pending_dispatcher_request_ = std::move(dispatcher_request);
 
   inflight_start_task_.reset(
       new StartTask(this, params->script_url, std::move(request)));
   inflight_start_task_->Start(std::move(params), callback);
 }
 
 ServiceWorkerStatusCode EmbeddedWorkerInstance::Stop() {
   DCHECK(status_ == EmbeddedWorkerStatus::STARTING ||
          status_ == EmbeddedWorkerStatus::RUNNING)
       << static_cast<int>(status_);

[falken, 2016/12/20 04:47:12]

Also wouldn't this DCHECK fail if Stop() is called twice?

[shimazu, 2016/12/20 07:55:01]

Yes, I think so.

 
   // Abort an inflight start task.
   inflight_start_task_.reset();
 
-  ServiceWorkerStatusCode status = SERVICE_WORKER_ERROR_IPC_FAILED;
+  ServiceWorkerStatusCode status = SERVICE_WORKER_OK;
   if (ServiceWorkerUtils::IsMojoForServiceWorkerEnabled()) {
-    status = SERVICE_WORKER_OK;
-    client_->StopWorker(base::Bind(&EmbeddedWorkerRegistry::OnWorkerStopped,
-                                   base::Unretained(registry_.get()),
-                                   process_id(), embedded_worker_id()));
+    if (status_ == EmbeddedWorkerStatus::STARTING) {
+      // Abort sending StopWorker message when the connection hasn't been
+      // established yet.
+      switch (starting_phase()) {
+        case NOT_STARTING:
+          NOTREACHED();
+        case ALLOCATING_PROCESS:
+          status = SERVICE_WORKER_ERROR_PROCESS_NOT_FOUND;
+          break;
+        case REGISTERING_TO_DEVTOOLS:
+          status = SERVICE_WORKER_ERROR_IPC_FAILED;

[falken, 2016/12/20 04:41:31]

Hm I don't think we really need to log these as errors. The point of
SendStopWorker status was to track when sending an IPC fails. But this
Mojo-based code is really just avoiding sending a Stop before a Start was sent.
IPC_FAILED in particular feels misleading.

Basically I think SendStopWorker shouldn't be logged in the mojo case, WDYT?

[shimazu, 2016/12/20 07:55:01]

Removing the uma seems good. Removed.

+          break;
+        case SENT_START_WORKER:
+        case SCRIPT_DOWNLOADING:
+        case SCRIPT_READ_STARTED:
+        case SCRIPT_READ_FINISHED:
+        case SCRIPT_LOADED:
+        case THREAD_STARTED:
+        case SCRIPT_EVALUATED:
+          status = SERVICE_WORKER_OK;
+          break;
+        case STARTING_PHASE_MAX_VALUE:
+          NOTREACHED();
+          status = SERVICE_WORKER_ERROR_ABORT;
+          break;
+      }
+    }
   } else {
     status = registry_->StopWorker(process_id(), embedded_worker_id_);
   }
+
   UMA_HISTOGRAM_ENUMERATION("ServiceWorker.SendStopWorker.Status", status,
                             SERVICE_WORKER_ERROR_MAX_VALUE);
-  // StopWorker could fail if we were starting up and don't have a process yet,
-  // or we can no longer communicate with the process. So just detach.
+  // StopWorker could fail if we were starting up and don't have a process
+  // yet, or we can no longer communicate with the process. So just detach.
   if (status != SERVICE_WORKER_OK) {
     OnDetached();
     return status;
   }
 
+  if (ServiceWorkerUtils::IsMojoForServiceWorkerEnabled()) {
+    client_->StopWorker(base::Bind(&EmbeddedWorkerRegistry::OnWorkerStopped,
+                                   base::Unretained(registry_.get()),
+                                   process_id(), embedded_worker_id()));
+  }
   status_ = EmbeddedWorkerStatus::STOPPING;
   for (auto& observer : listener_list_)
     observer.OnStopping();
   return status;
 }
 
 void EmbeddedWorkerInstance::StopIfIdle() {
   if (devtools_attached_) {
     if (devtools_proxy_) {
       // Check ShouldNotifyWorkerStopIgnored not to show the same message
@@ skipping 411 matching lines @@
     case SCRIPT_READ_FINISHED:
       return "Script read finished";
     case STARTING_PHASE_MAX_VALUE:
       NOTREACHED();
   }
   NOTREACHED() << phase;
   return std::string();
 }
 
 }  // namespace content