Split initialization_util into a Hermetic Library and a Variations Library

components/task_scheduler_util/initialization/browser_util.cc

Index: components/task_scheduler_util/initialization/browser_util.cc
diff --git a/components/task_scheduler_util/initialization/browser_util.cc b/components/task_scheduler_util/initialization/browser_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e9b7a535c1cf0cb285b04fc72d32ea7cc18da24f
--- /dev/null
+++ b/components/task_scheduler_util/initialization/browser_util.cc
@@ -0,0 +1,147 @@
+// Copyright 2016 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 "components/task_scheduler_util/initialization/browser_util.h"
+
+#include <map>
+#include <string>
+
+#include "base/task_scheduler/initialization_util.h"
+#include "base/task_scheduler/switches.h"
+#include "base/task_scheduler/task_traits.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "build/build_config.h"
+
+namespace task_scheduler_util {
+namespace initialization {
+
+namespace {
+
+using StandbyThreadPolicy =
+    base::SchedulerWorkerPoolParams::StandbyThreadPolicy;
+using ThreadPriority = base::ThreadPriority;
+
+struct SchedulerWorkerPoolConfiguration {
+  const char* name;
+  ThreadPriority priority_hint;
+  const SingleWorkerPoolConfiguration& config;
+
+  SchedulerWorkerPoolConfiguration(
+      const char* name,
+      ThreadPriority priority_hint,
+      const SingleWorkerPoolConfiguration& config)
+      : name(name),
+        priority_hint(priority_hint),
+        config(config) {}
+};
+
+}  // namespace
+
+std::vector<base::SchedulerWorkerPoolParams>
+BrowserWorkerPoolConfigurationToSchedulerWorkerPoolParams(
+    const BrowserWorkerPoolsConfiguration& config) {
+  const SchedulerWorkerPoolConfiguration worker_pool_config[] = {
+      SchedulerWorkerPoolConfiguration("Background",
+                                       ThreadPriority::BACKGROUND,
+                                       config.background),
+      SchedulerWorkerPoolConfiguration("BackgroundFileIO",
+                                       ThreadPriority::BACKGROUND,
+                                       config.background_file_io),
+      SchedulerWorkerPoolConfiguration("Foreground",
+                                       ThreadPriority::NORMAL,
+                                       config.foreground),
+      SchedulerWorkerPoolConfiguration("ForegroundFileIO",
+                                       ThreadPriority::NORMAL,
+                                       config.foreground_file_io),
+
+  };
+  static_assert(arraysize(worker_pool_config) == WORKER_POOL_COUNT,
+                "Mismatched Worker Pool Types and Predefined Parameters");
+  constexpr size_t kNumWorkerPoolsDefined = sizeof(config) /
+                                            sizeof(config.background);
+  static_assert(arraysize(worker_pool_config) == kNumWorkerPoolsDefined,
+                "Mismatch in predefined parameters and worker pools.");
+  std::vector<base::SchedulerWorkerPoolParams> params_vector;
+  for (size_t i = 0; i < arraysize(worker_pool_config); ++i) {
+    const auto* const config = &worker_pool_config[i];
+    params_vector.emplace_back(
+        config->name, config->priority_hint,
+        config->config.standby_thread_policy, config->config.threads,
+        config->config.detach_period);
+  }
+  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.
+size_t BrowserWorkerPoolIndexForTraits(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;
+}
+
+std::vector<base::SchedulerWorkerPoolParams>
+GetDefaultBrowserSchedulerWorkerPoolParams() {
+  constexpr size_t kNumWorkerPoolsDefined =
+      sizeof(BrowserWorkerPoolsConfiguration) /
+      sizeof(SingleWorkerPoolConfiguration);
+  static_assert(kNumWorkerPoolsDefined == 4,
+                "Expected 4 worker pools in BrowserWorkerPoolsConfiguration");
+  BrowserWorkerPoolsConfiguration config;
+  constexpr size_t kSizeAssignedFields =
+      sizeof(config.background.threads) +
+      sizeof(config.background.detach_period) +
+      sizeof(config.background.standby_thread_policy);
+  static_assert(kSizeAssignedFields == sizeof(config.background),
+                "Not all fields were assigned");
+#if defined(OS_ANDROID) || defined(OS_IOS)
+  config.background.standby_thread_policy = StandbyThreadPolicy::ONE;
+  config.background.threads =
+      base::RecommendedMaxNumberOfThreadsInPool(2, 8, 0.1, 0);
+  config.background.detach_period = base::TimeDelta::FromSeconds(30);
+
+  config.background_file_io.standby_thread_policy = StandbyThreadPolicy::ONE;
+  config.background_file_io.threads =
+      base::RecommendedMaxNumberOfThreadsInPool(2, 8, 0.1, 0);
+  config.background_file_io.detach_period = base::TimeDelta::FromSeconds(30);
+
+  config.foreground.standby_thread_policy = StandbyThreadPolicy::ONE;
+  config.foreground.threads =
+      base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.3, 0);
+  config.foreground.detach_period = base::TimeDelta::FromSeconds(30);
+
+  config.foreground_file_io.standby_thread_policy = StandbyThreadPolicy::ONE;
+  config.foreground_file_io.threads =
+      base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.3, 0);
+  config.foreground_file_io.detach_period = base::TimeDelta::FromSeconds(30);
+#else
+  config.background.standby_thread_policy = StandbyThreadPolicy::ONE;
+  config.background.threads =
+      base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.1, 0);
+  config.background.detach_period = base::TimeDelta::FromSeconds(30);
+
+  config.background_file_io.standby_thread_policy = StandbyThreadPolicy::ONE;
+  config.background_file_io.threads =
+      base::RecommendedMaxNumberOfThreadsInPool(3, 8, 0.1, 0);
+  config.background_file_io.detach_period = base::TimeDelta::FromSeconds(30);
+
+  config.foreground.standby_thread_policy = StandbyThreadPolicy::ONE;
+  config.foreground.threads =
+      base::RecommendedMaxNumberOfThreadsInPool(8, 32, 0.3, 0);
+  config.foreground.detach_period = base::TimeDelta::FromSeconds(30);
+
+  config.foreground_file_io.standby_thread_policy = StandbyThreadPolicy::ONE;
+  config.foreground_file_io.threads =
+      base::RecommendedMaxNumberOfThreadsInPool(8, 32, 0.3, 0);
+  config.foreground_file_io.detach_period = base::TimeDelta::FromSeconds(30);
+#endif
+  return BrowserWorkerPoolConfigurationToSchedulerWorkerPoolParams(config);
+}
+
+}  // namespace initialization
+}  // namespace task_scheduler_util