[reference - do not submit] Always create four pools in TaskSchedulerImpl.

content/browser/browser_main_loop.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/browser/browser_main_loop.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 16 matching lines @@
 #include "base/power_monitor/power_monitor_device_source.h"
 #include "base/process/process_metrics.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/system_monitor/system_monitor.h"
 #include "base/task_scheduler/initialization_util.h"
 #include "base/task_scheduler/post_task.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/sequenced_worker_pool.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/timer/hi_res_timer_manager.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
@@ skipping 364 matching lines @@
 #endif  // defined(OS_WIN)
 
 enum WorkerPoolType : size_t {
   BACKGROUND = 0,
   BACKGROUND_BLOCKING,
   FOREGROUND,
   FOREGROUND_BLOCKING,
   WORKER_POOL_COUNT  // Always last.
 };
 
-std::vector<base::SchedulerWorkerPoolParams>
-GetDefaultSchedulerWorkerPoolParams() {
+std::unique_ptr<base::TaskSchedulerInitParams>
+GetDefaultTaskSchedulerInitParams() {
   using StandbyThreadPolicy =
       base::SchedulerWorkerPoolParams::StandbyThreadPolicy;
-  using ThreadPriority = base::ThreadPriority;
-  std::vector<base::SchedulerWorkerPoolParams> params_vector;
 #if defined(OS_ANDROID)
-  params_vector.emplace_back(
-      "Background", ThreadPriority::BACKGROUND, StandbyThreadPolicy::ONE,
-       base::RecommendedMaxNumberOfThreadsInPool(2, 8, 0.1, 0),
-       base::TimeDelta::FromSeconds(30));
-  params_vector.emplace_back(
-      "BackgroundBlocking", ThreadPriority::BACKGROUND,
-      StandbyThreadPolicy::ONE,
-      base::RecommendedMaxNumberOfThreadsInPool(2, 8, 0.1, 0),
-      base::TimeDelta::FromSeconds(30));
-  params_vector.emplace_back(
-      "Foreground", ThreadPriority::NORMAL, StandbyThreadPolicy::ONE,
-       base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.3, 0),
-       base::TimeDelta::FromSeconds(30));
-  params_vector.emplace_back(
-      "ForegroundBlocking", ThreadPriority::NORMAL, StandbyThreadPolicy::ONE,
-      base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.3, 0),
-      base::TimeDelta::FromSeconds(30));
+  return base::MakeUnique<base::TaskSchedulerInitParams>(
+      base::SchedulerWorkerPoolParams(
+          StandbyThreadPolicy::ONE,
+          base::RecommendedMaxNumberOfThreadsInPool(2, 8, 0.1, 0),
+          base::TimeDelta::FromSeconds(30)),
+      base::SchedulerWorkerPoolParams(
+          StandbyThreadPolicy::ONE,
+          base::RecommendedMaxNumberOfThreadsInPool(2, 8, 0.1, 0),
+          base::TimeDelta::FromSeconds(30)),
+      base::SchedulerWorkerPoolParams(
+          StandbyThreadPolicy::ONE,
+          base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.3, 0),
+          base::TimeDelta::FromSeconds(30)),
+      base::SchedulerWorkerPoolParams(
+          StandbyThreadPolicy::ONE,
+          base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.3, 0),
+          base::TimeDelta::FromSeconds(30)));
 #else
-  params_vector.emplace_back(
-      "Background", ThreadPriority::BACKGROUND, StandbyThreadPolicy::ONE,
-       base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.1, 0),
-       base::TimeDelta::FromSeconds(30));
-  params_vector.emplace_back(
-      "BackgroundBlocking", ThreadPriority::BACKGROUND,
-      StandbyThreadPolicy::ONE,
-      base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.1, 0),
-      base::TimeDelta::FromSeconds(30));
-  params_vector.emplace_back(
-      "Foreground", ThreadPriority::NORMAL, StandbyThreadPolicy::ONE,
-       base::RecommendedMaxNumberOfThreadsInPool(8, 32, 0.3, 0),
-       base::TimeDelta::FromSeconds(30));
-  // Tasks posted to SequencedWorkerPool or BrowserThreadImpl may be redirected
-  // to this pool. Since COM STA is initialized in these environments, it must
-  // also be initialized in this pool.
-  params_vector.emplace_back(
-      "ForegroundBlocking", ThreadPriority::NORMAL, StandbyThreadPolicy::ONE,
-      base::RecommendedMaxNumberOfThreadsInPool(8, 32, 0.3, 0),
-      base::TimeDelta::FromSeconds(30),
-      base::SchedulerBackwardCompatibility::INIT_COM_STA);
+  return base::MakeUnique<base::TaskSchedulerInitParams>(
+      base::SchedulerWorkerPoolParams(
+          StandbyThreadPolicy::ONE,
+          base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.1, 0),
+          base::TimeDelta::FromSeconds(30)),
+      base::SchedulerWorkerPoolParams(
+          StandbyThreadPolicy::ONE,
+          base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.1, 0),
+          base::TimeDelta::FromSeconds(30)),
+      base::SchedulerWorkerPoolParams(
+          StandbyThreadPolicy::ONE,
+          base::RecommendedMaxNumberOfThreadsInPool(8, 32, 0.3, 0),
+          base::TimeDelta::FromSeconds(30)),
+      // Tasks posted to SequencedWorkerPool or BrowserThreadImpl may be
+      // redirected to this pool. Since COM STA is initialized in these
+      // environments, it must also be initialized in this pool.
+      base::SchedulerWorkerPoolParams(
+          StandbyThreadPolicy::ONE,
+          base::RecommendedMaxNumberOfThreadsInPool(8, 32, 0.3, 0),
+          base::TimeDelta::FromSeconds(30),
+          base::SchedulerBackwardCompatibility::INIT_COM_STA));
 #endif
-  DCHECK_EQ(WORKER_POOL_COUNT, params_vector.size());
-  return params_vector;
-}
-
-// Returns the worker pool index for |traits| defaulting to FOREGROUND or
-// FOREGROUND_BLOCKING on any other priorities based off of worker pools defined
-// in GetDefaultSchedulerWorkerPoolParams().
-size_t DefaultBrowserWorkerPoolIndexForTraits(const base::TaskTraits& traits) {
-  const bool is_background =
-      traits.priority() == base::TaskPriority::BACKGROUND;
-  if (traits.may_block() || traits.with_base_sync_primitives())
-    return is_background ? BACKGROUND_BLOCKING : FOREGROUND_BLOCKING;
-
-  return is_background ? BACKGROUND : FOREGROUND;
 }
 
 }  // namespace
 
 #if defined(USE_X11) && !defined(OS_CHROMEOS)
 namespace internal {
 
 // Forwards GPUInfo updates to ui::XVisualManager
 class GpuDataManagerVisualProxy : public GpuDataManagerObserver {
  public:
@@ skipping 493 matching lines @@
     startup_task_runner_->RunAllTasksNow();
   }
 #else
   startup_task_runner_->RunAllTasksNow();
 #endif
 }
 
 int BrowserMainLoop::CreateThreads() {
   TRACE_EVENT0("startup,rail", "BrowserMainLoop::CreateThreads");
 
-  std::vector<base::SchedulerWorkerPoolParams> params_vector;
-  base::TaskScheduler::WorkerPoolIndexForTraitsCallback
-      index_to_traits_callback;
-  GetContentClient()->browser()->GetTaskSchedulerInitializationParams(
-      &params_vector, &index_to_traits_callback);
-
-  if (params_vector.empty() || index_to_traits_callback.is_null()) {
-    params_vector = GetDefaultSchedulerWorkerPoolParams();
-    index_to_traits_callback =
-        base::Bind(&DefaultBrowserWorkerPoolIndexForTraits);
+  auto task_scheduler_init_params =
+      GetContentClient()->browser()->GetTaskSchedulerInitParams();
+  if (!task_scheduler_init_params) {
+    task_scheduler_init_params = GetDefaultTaskSchedulerInitParams();
   }
+  DCHECK(task_scheduler_init_params);
+  DCHECK(task_scheduler_init_params->IsValid());
 
   base::TaskScheduler::CreateAndSetDefaultTaskScheduler(
-      params_vector, index_to_traits_callback);
+      "", *task_scheduler_init_params.get());
 
   GetContentClient()->browser()->PerformExperimentalTaskSchedulerRedirections();
 
   base::Thread::Options io_message_loop_options;
   io_message_loop_options.message_loop_type = base::MessageLoop::TYPE_IO;
   base::Thread::Options ui_message_loop_options;
   ui_message_loop_options.message_loop_type = base::MessageLoop::TYPE_UI;
 
   const bool redirect_nonUInonIO_browser_threads =
       GetContentClient()
@@ skipping 772 matching lines @@
         BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE),
         MediaInternals::GetInstance());
   }
   CHECK(audio_manager_);
 
   audio_system_ = media::AudioSystemImpl::Create(audio_manager_.get());
   CHECK(audio_system_);
 }
 
 }  // namespace content