Initialize TaskScheduler in renderers.

content/renderer/render_process_impl.cc

 // Copyright (c) 2012 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/renderer/render_process_impl.h"
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <objidl.h>
 #include <mlang.h>
 #endif
 
+#include <stddef.h>
+
+#include <vector>
+
+#include "base/callback.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/feature_list.h"
 #include "base/sys_info.h"
+#include "base/task_scheduler/scheduler_worker_pool_params.h"
+#include "base/task_scheduler/task_scheduler.h"
+#include "base/threading/sequenced_worker_pool.h"
 #include "content/child/site_isolation_stats_gatherer.h"
 #include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/renderer/content_renderer_client.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
 #include "v8/include/v8.h"
 
+namespace base {
+class TaskTraits;
+}  // namespace
+
 namespace {
 
 const base::Feature kV8_ES2015_TailCalls_Feature {
   "V8_ES2015_TailCalls", base::FEATURE_DISABLED_BY_DEFAULT
 };
 
 const base::Feature kV8_ES2016_ExplicitTailCalls_Feature{
     "V8_ES2016_ExplicitTailCalls", base::FEATURE_DISABLED_BY_DEFAULT};
 
 const base::Feature kV8SerializeEagerFeature{"V8_Serialize_Eager",
                                              base::FEATURE_DISABLED_BY_DEFAULT};
 
 const base::Feature kV8SerializeAgeCodeFeature{
     "V8_Serialize_Age_Code", base::FEATURE_DISABLED_BY_DEFAULT};
 
 void SetV8FlagIfFeature(const base::Feature& feature, const char* v8_flag) {
   if (base::FeatureList::IsEnabled(feature)) {
     v8::V8::SetFlagsFromString(v8_flag, strlen(v8_flag));
   }
 }
 
 void SetV8FlagIfHasSwitch(const char* switch_name, const char* v8_flag) {
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(switch_name)) {
     v8::V8::SetFlagsFromString(v8_flag, strlen(v8_flag));
   }
 }
 
+bool IsSingleProcess() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kSingleProcess);
+}
+
+void InitializeTaskScheduler() {
+  if (IsSingleProcess()) {
+    // If this renderer runs in the browser process, there should already be a
+    // TaskScheduler and redirection settings shouldn't be changed.
+    DCHECK(base::TaskScheduler::GetInstance());
+    return;
+  }
+  DCHECK(!base::TaskScheduler::GetInstance());
+
+  std::vector<base::SchedulerWorkerPoolParams> worker_pool_params_vector;
+  base::Callback<size_t(const base::TaskTraits& traits)>

[gab, 2016/11/18 18:32:00]

Feels like this type should be defined somewhere.

using SchedulerWorkerPoolSelector = Callback<size_t(const TaskTraits& traits)>;

in task_scheduler.h?

+      worker_pool_index_for_traits_callback;
+  bool redirect_sequenced_worker_pool = false;
+
+  content::GetContentClient()
+      ->renderer()
+      ->GetTaskSchedulerInitializationArguments(
+          &worker_pool_params_vector, &worker_pool_index_for_traits_callback,
+          &redirect_sequenced_worker_pool);
+  DCHECK(!worker_pool_params_vector.empty());
+  DCHECK(worker_pool_index_for_traits_callback);
+
+  base::TaskScheduler::CreateAndSetDefaultTaskScheduler(
+      worker_pool_params_vector, worker_pool_index_for_traits_callback);
+
+  if (redirect_sequenced_worker_pool)
+    base::SequencedWorkerPool::RedirectToTaskSchedulerForProcess();

[gab, 2016/11/18 18:32:00]

else EnableForProcess?

(won't there be a clash with your other CL if redirect/enable decision isn't in
same place? or is this just because this one doesn't currently depend on the
other?)

+}
+
 }  // namespace
 
 namespace content {
 
 RenderProcessImpl::RenderProcessImpl()
     : enabled_bindings_(0) {
 #if defined(OS_WIN)
   // HACK:  See http://b/issue?id=1024307 for rationale.
   if (GetModuleHandle(L"LPK.DLL") == NULL) {
     // Makes sure lpk.dll is loaded by gdi32 to make sure ExtTextOut() works
@@ skipping 33 matching lines @@
       *base::CommandLine::ForCurrentProcess();
 
   if (command_line.HasSwitch(switches::kJavaScriptFlags)) {
     std::string flags(
         command_line.GetSwitchValueASCII(switches::kJavaScriptFlags));
     v8::V8::SetFlagsFromString(flags.c_str(), static_cast<int>(flags.size()));
   }
 
   SiteIsolationStatsGatherer::SetEnabled(
       GetContentClient()->renderer()->ShouldGatherSiteIsolationStats());
+
+  InitializeTaskScheduler();
 }
 
 RenderProcessImpl::~RenderProcessImpl() {
 #ifndef NDEBUG
   int count = blink::WebFrame::instanceCount();
   if (count)
     DLOG(ERROR) << "WebFrame LEAKED " << count << " TIMES";
 #endif
 
+  if (!IsSingleProcess()) {
+    DCHECK(base::TaskScheduler::GetInstance());
+    base::TaskScheduler::GetInstance()->Shutdown();
+  }
+
   GetShutDownEvent()->Signal();
 }
 
 void RenderProcessImpl::AddBindings(int bindings) {
   enabled_bindings_ |= bindings;
 }
 
 int RenderProcessImpl::GetEnabledBindings() const {
   return enabled_bindings_;
 }
 
 }  // namespace content