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/bind.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/initialization_util.h"
+#include "base/task_scheduler/scheduler_worker_pool_params.h"
+#include "base/task_scheduler/task_scheduler.h"
+#include "base/task_scheduler/task_traits.h"
+#include "base/threading/platform_thread.h"
+#include "base/time/time.h"
 #include "content/child/site_isolation_stats_gatherer.h"
+#include "content/public/common/content_client.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 {
 
+enum WorkerPoolType : size_t {
+  BACKGROUND = 0,
+  BACKGROUND_FILE_IO,
+  FOREGROUND,
+  FOREGROUND_FILE_IO,
+  WORKER_POOL_COUNT  // Always last.
+};
+
 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));
   }
 }
 
+std::vector<base::SchedulerWorkerPoolParams>
+GetDefaultSchedulerWorkerPoolParams() {
+  using StandbyThreadPolicy =
+      base::SchedulerWorkerPoolParams::StandbyThreadPolicy;
+  using ThreadPriority = base::ThreadPriority;
+  std::vector<base::SchedulerWorkerPoolParams> params_vector;
+  params_vector.emplace_back("RendererBackground", ThreadPriority::BACKGROUND,
+                             StandbyThreadPolicy::LAZY, 1,

[jam, 2016/12/13 01:28:22]

all the numbers here and below are magic to someone not familiar with it. please
move them to constants 

[fdoray, 2016/12/13 16:19:51]

Done.

+                             base::TimeDelta::FromSeconds(30));
+  params_vector.emplace_back(
+      "RendererBackgroundFileIO", ThreadPriority::BACKGROUND,
+      StandbyThreadPolicy::LAZY, 1, base::TimeDelta::FromSeconds(30));
+  params_vector.emplace_back(
+      "RendererForeground", ThreadPriority::NORMAL, StandbyThreadPolicy::LAZY,
+      base::RecommendedMaxNumberOfThreadsInPool(2, 4, 1, 0),
+      base::TimeDelta::FromSeconds(30));
+  params_vector.emplace_back("RendererForegroundFileIO", ThreadPriority::NORMAL,
+                             StandbyThreadPolicy::LAZY, 1,
+                             base::TimeDelta::FromSeconds(30));
+  DCHECK_EQ(WORKER_POOL_COUNT, params_vector.size());
+  return params_vector;
+}
+
+// Returns the worker pool index for |traits| defaulting to FOREGROUND or
+// FOREGROUND_FILE_IO on any other priorities based off of worker pools defined
+// in GetDefaultSchedulerWorkerPoolParams().
+size_t DefaultRendererWorkerPoolIndexForTraits(const base::TaskTraits& traits) {
+  const bool is_background =
+      traits.priority() == base::TaskPriority::BACKGROUND;
+  if (traits.with_file_io())
+    return is_background ? BACKGROUND_FILE_IO : FOREGROUND_FILE_IO;
+
+  return is_background ? BACKGROUND : FOREGROUND;
+}
+
+bool IsSingleProcess() {

[jam, 2016/12/13 01:28:22]

nit: we don't generally use helper methods for checking one command line flag

[fdoray, 2016/12/13 16:19:51]

Done.

+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kSingleProcess);
+}
+
+void InitializeTaskScheduler() {
+  if (IsSingleProcess()) {
+    // There should already be a TaskScheduler when the renderer runs inside the
+    // browser process.
+    DCHECK(base::TaskScheduler::GetInstance());
+    return;
+  }
+  DCHECK(!base::TaskScheduler::GetInstance());
+
+  std::vector<base::SchedulerWorkerPoolParams> params_vector;
+  base::TaskScheduler::WorkerPoolIndexForTraitsCallback
+      index_to_traits_callback;
+  content::GetContentClient()->renderer()->GetTaskSchedulerInitializationParams(
+      &params_vector, &index_to_traits_callback);
+
+  if (params_vector.empty()) {
+    params_vector = GetDefaultSchedulerWorkerPoolParams();
+    index_to_traits_callback =
+        base::Bind(&DefaultRendererWorkerPoolIndexForTraits);
+  }
+  DCHECK(index_to_traits_callback);
+
+  base::TaskScheduler::CreateAndSetDefaultTaskScheduler(
+      params_vector, index_to_traits_callback);
+}
+
 }  // 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