Teach EmbeddedWorkerInstance to create a process when it needs one.

content/browser/service_worker/service_worker_context_wrapper.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/service_worker_context_wrapper.h"
 
+#include "base/callback.h"
 #include "base/files/file_path.h"
+#include "base/lazy_instance.h"
+#include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/browser/service_worker/service_worker_context_core.h"
 #include "content/browser/service_worker/service_worker_context_observer.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/site_instance.h"
 #include "webkit/browser/quota/quota_manager_proxy.h"
 
 namespace content {
+namespace {
+base::LazyInstance<base::Callback<bool(int)> > s_increment_worker_refcount;
+base::LazyInstance<base::Callback<bool(int)> > s_decrement_worker_refcount;

[kinuko, 2014/04/25 13:46:35]

Whoa... ah ok it's for testing.

[Jeffrey Yasskin, 2014/04/26 03:52:19]

And gone now.

+
+bool IncrementWorkerRefcountByPid(int process_id) {
+  if (!s_increment_worker_refcount.Get().is_null())
+    return s_increment_worker_refcount.Get().Run(process_id);
+
+  RenderProcessHost* rph = RenderProcessHost::FromID(process_id);
+  if (rph)

[kinuko, 2014/04/25 13:46:35]

Probably also check if (!rph->FastShutdownStarted()) ?

[Jeffrey Yasskin, 2014/04/26 03:52:19]

Done.

+    static_cast<RenderProcessHostImpl*>(rph)->IncrementWorkerRefCount();
+
+  return rph;

[kinuko, 2014/04/25 13:46:35]

I prefer explicitly return a boolean value.

[Jeffrey Yasskin, 2014/04/26 03:52:19]

Done.

+}
+
+bool DecrementWorkerRefcountByPid(int process_id) {
+  if (!s_decrement_worker_refcount.Get().is_null())
+    return s_decrement_worker_refcount.Get().Run(process_id);
+
+  RenderProcessHost* rph = RenderProcessHost::FromID(process_id);
+  if (rph)
+    static_cast<RenderProcessHostImpl*>(rph)->DecrementWorkerRefCount();
+
+  return rph;
+}
+}  // namespace
 
 ServiceWorkerContextWrapper::ServiceWorkerContextWrapper()
-    : observer_list_(
-          new ObserverListThreadSafe<ServiceWorkerContextObserver>()) {}
+    : browser_context_(NULL),
+      observer_list_(
+          new ObserverListThreadSafe<ServiceWorkerContextObserver>()) {
+}
 
 ServiceWorkerContextWrapper::~ServiceWorkerContextWrapper() {
 }
 
 void ServiceWorkerContextWrapper::Init(
     const base::FilePath& user_data_directory,
     quota::QuotaManagerProxy* quota_manager_proxy) {
   if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE,
         base::Bind(&ServiceWorkerContextWrapper::Init, this,
                    user_data_directory,
                    make_scoped_refptr(quota_manager_proxy)));
     return;
   }
   DCHECK(!context_core_);
   context_core_.reset(new ServiceWorkerContextCore(
-      user_data_directory, quota_manager_proxy, observer_list_));
+      this, user_data_directory, quota_manager_proxy, observer_list_));
 }
 
 void ServiceWorkerContextWrapper::Shutdown() {
   if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+    browser_context_ = NULL;
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE,
         base::Bind(&ServiceWorkerContextWrapper::Shutdown, this));
     return;
   }
+  // This breaks a reference cycle from Core::wrapper_ back to this object.
   context_core_.reset();
 }
 
 ServiceWorkerContextCore* ServiceWorkerContextWrapper::context() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   return context_core_.get();
 }
 
+void ServiceWorkerContextWrapper::IncrementWorkerRef(
+    const std::vector<int>& process_ids,
+    const GURL& script_url,
+    const base::Callback<void(ServiceWorkerStatusCode, int process_id)>&
+        callback) const {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  for (std::vector<int>::const_iterator it = process_ids.begin();
+       it != process_ids.end();
+       ++it) {
+    if (IncrementWorkerRefcountByPid(*it)) {
+      BrowserThread::PostTask(BrowserThread::IO,
+                              FROM_HERE,
+                              base::Bind(callback, SERVICE_WORKER_OK, *it));
+      return;
+    }
+  }
+
+  if (!browser_context_) {
+    // If all of the processes that requested a SW went away before it was
+    // created, we should just ignore the request.
+    LOG(ERROR) << "Couldn't start a new process!";
+    BrowserThread::PostTask(
+        BrowserThread::IO,
+        FROM_HERE,
+        base::Bind(callback, SERVICE_WORKER_ERROR_START_WORKER_FAILED, -1));
+    return;
+  }
+
+  // No existing processes available; start a new one.
+  scoped_refptr<SiteInstance> site_instance =
+      SiteInstance::CreateForURL(browser_context_, script_url);
+  RenderProcessHost* rph = site_instance->GetProcess();
+  // This Init() call posts a task to the IO thread that adds the RPH's
+  // ServiceWorkerDispatcherHost to the
+  // EmbeddedWorkerRegistry::process_sender_map_.
+  if (!rph->Init()) {
+    LOG(ERROR) << "Couldn't start a new process!";
+    BrowserThread::PostTask(
+        BrowserThread::IO,
+        FROM_HERE,
+        base::Bind(callback, SERVICE_WORKER_ERROR_START_WORKER_FAILED, -1));
+    return;
+  }
+
+  static_cast<RenderProcessHostImpl*>(rph)->IncrementWorkerRefCount();
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(callback, SERVICE_WORKER_OK, rph->GetID()));
+}
+
+void ServiceWorkerContextWrapper::DecrementWorkerRef(int process_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  if (!DecrementWorkerRefcountByPid(process_id)) {
+    DCHECK(false) << "DecrementWorkerRef(" << process_id
+                  << ") doesn't match a previous IncrementWorkerRef";
+  }
+}
+
 static void FinishRegistrationOnIO(
     const ServiceWorkerContext::ResultCallback& continuation,
     ServiceWorkerStatusCode status,
     int64 registration_id,
     int64 version_id) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (status != SERVICE_WORKER_OK)
+    LOG(ERROR) << ServiceWorkerStatusToString(status);
   BrowserThread::PostTask(
       BrowserThread::UI,
       FROM_HERE,
       base::Bind(continuation, status == SERVICE_WORKER_OK));
 }
 
 void ServiceWorkerContextWrapper::RegisterServiceWorker(
     const GURL& pattern,
     const GURL& script_url,
-    int source_process_id,
+    BrowserContext* browser_context,
     const ResultCallback& continuation) {
-  if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
+  if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    DCHECK(browser_context != NULL);
+    if (browser_context_ != NULL) {
+      DCHECK_EQ(browser_context_, browser_context)
+          << "|context| must be the BrowserContext containing *this.";
+    }
+    browser_context_ = browser_context;
     BrowserThread::PostTask(
         BrowserThread::IO,
         FROM_HERE,
         base::Bind(&ServiceWorkerContextWrapper::RegisterServiceWorker,
                    this,
                    pattern,
                    script_url,
-                   source_process_id,
+                   browser_context,
                    continuation));
     return;
   }
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   context()->RegisterServiceWorker(
       pattern,
       script_url,
-      source_process_id,
+      -1,
       NULL /* provider_host */,
       base::Bind(&FinishRegistrationOnIO, continuation));
 }
 
 static void FinishUnregistrationOnIO(
     const ServiceWorkerContext::ResultCallback& continuation,
     ServiceWorkerStatusCode status) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (status != SERVICE_WORKER_OK)
+    LOG(ERROR) << ServiceWorkerStatusToString(status);
   BrowserThread::PostTask(
       BrowserThread::UI,
       FROM_HERE,
       base::Bind(continuation, status == SERVICE_WORKER_OK));
 }
 
 void ServiceWorkerContextWrapper::UnregisterServiceWorker(
     const GURL& pattern,
     int source_process_id,
     const ResultCallback& continuation) {
@@ skipping 19 matching lines @@
 void ServiceWorkerContextWrapper::AddObserver(
     ServiceWorkerContextObserver* observer) {
   observer_list_->AddObserver(observer);
 }
 
 void ServiceWorkerContextWrapper::RemoveObserver(
     ServiceWorkerContextObserver* observer) {
   observer_list_->RemoveObserver(observer);
 }
 
+void ServiceWorkerContextWrapper::ResetWorkerRefCountOperationsForTest(
+    const base::Callback<bool(int)>& increment,
+    const base::Callback<bool(int)>& decrement) {
+  s_increment_worker_refcount.Get() = increment;
+  s_decrement_worker_refcount.Get() = decrement;
+}
+
 }  // namespace content