Virtualize The Existence of a Scheduler Worker Thread

base/task_scheduler/scheduler_worker_pool_impl.cc

 // 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 "base/task_scheduler/scheduler_worker_pool_impl.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
@@ skipping 183 matching lines @@
 
   PriorityQueue* single_threaded_priority_queue() {
     return &single_threaded_priority_queue_;
   }
 
   // SchedulerWorker::Delegate:
   void OnMainEntry(SchedulerWorker* worker) override;
   scoped_refptr<Sequence> GetWork(SchedulerWorker* worker) override;
   void ReEnqueueSequence(scoped_refptr<Sequence> sequence) override;
   TimeDelta GetSleepTimeout() override;
+  bool CanDetach(SchedulerWorker* worker) override;
 
  private:
   SchedulerWorkerPoolImpl* outer_;
   const ReEnqueueSequenceCallback re_enqueue_sequence_callback_;
 
   // Single-threaded PriorityQueue for the worker.
   PriorityQueue single_threaded_priority_queue_;
 
   // True if the last Sequence returned by GetWork() was extracted from
   // |single_threaded_priority_queue_|.
@@ skipping 257 matching lines @@
     // |sequence| must be enqueued.
     re_enqueue_sequence_callback_.Run(std::move(sequence));
   }
 }
 
 TimeDelta SchedulerWorkerPoolImpl::SchedulerWorkerDelegateImpl::
     GetSleepTimeout() {
   return TimeDelta::Max();
 }
 
+bool SchedulerWorkerPoolImpl::SchedulerWorkerDelegateImpl::CanDetach(
+    SchedulerWorker* worker) {
+  return false;
+}
+
 SchedulerWorkerPoolImpl::SchedulerWorkerPoolImpl(
     StringPiece name,
     IORestriction io_restriction,
     TaskTracker* task_tracker,
     DelayedTaskManager* delayed_task_manager)
     : name_(name.as_string()),
       io_restriction_(io_restriction),
       idle_workers_stack_lock_(shared_priority_queue_.container_lock()),
       idle_workers_stack_cv_for_testing_(
           idle_workers_stack_lock_.CreateConditionVariable()),
@@ skipping 16 matching lines @@
   AutoSchedulerLock auto_lock(idle_workers_stack_lock_);
 
   DCHECK(workers_.empty());
 
   for (size_t i = 0; i < max_threads; ++i) {
     std::unique_ptr<SchedulerWorker> worker =
         SchedulerWorker::Create(
             thread_priority, WrapUnique(new SchedulerWorkerDelegateImpl(
                                  this, re_enqueue_sequence_callback,
                                  &shared_priority_queue_, static_cast<int>(i))),
-            task_tracker_);
+            task_tracker_,
+            SchedulerWorker::InitialState::ALIVE);
     if (!worker)
       break;
     idle_workers_stack_.Push(worker.get());
     workers_.push_back(std::move(worker));
   }
 
 #if DCHECK_IS_ON()
   workers_created_.Signal();
 #endif
 
@@ skipping 21 matching lines @@
 }
 
 void SchedulerWorkerPoolImpl::RemoveFromIdleWorkersStack(
     SchedulerWorker* worker) {
   AutoSchedulerLock auto_lock(idle_workers_stack_lock_);
   idle_workers_stack_.Remove(worker);
 }
 
 }  // namespace internal
 }  // namespace base