TaskScheduler: Put an ALIVE SchedulerWorker on top of the idle stack.

base/task_scheduler/scheduler_worker_pool_impl.cc

Index: base/task_scheduler/scheduler_worker_pool_impl.cc
diff --git a/base/task_scheduler/scheduler_worker_pool_impl.cc b/base/task_scheduler/scheduler_worker_pool_impl.cc
index dc040301ca31af4868522b3983b112f293e0d28e..ea39a6bf7e383685f2d78dcb29a7732e0de1d341 100644
--- a/base/task_scheduler/scheduler_worker_pool_impl.cc
+++ b/base/task_scheduler/scheduler_worker_pool_impl.cc
@@ -698,12 +698,15 @@ bool SchedulerWorkerPoolImpl::Initialize(
   DCHECK(workers_.empty());
 
   for (size_t i = 0; i < max_threads; ++i) {
+    // The SchedulerWorker on top of the idle stack is initially ALIVE.

[robliao, 2016/10/12 20:22:17]

Oops! Nice catch.

I would drive this home even more: The last added thread should be ALIVE.

[fdoray, 2016/10/12 21:18:44]

Done.

+    const SchedulerWorker::InitialState initial_state =
+        (i == max_threads - 1) ? SchedulerWorker::InitialState::ALIVE
+                               : SchedulerWorker::InitialState::DETACHED;
     std::unique_ptr<SchedulerWorker> worker = SchedulerWorker::Create(
         priority_hint, MakeUnique<SchedulerWorkerDelegateImpl>(
                            this, re_enqueue_sequence_callback,
                            &shared_priority_queue_, static_cast<int>(i)),
-        task_tracker_, i == 0 ? SchedulerWorker::InitialState::ALIVE
-                              : SchedulerWorker::InitialState::DETACHED);
+        task_tracker_, initial_state);
     if (!worker)
       break;
     idle_workers_stack_.Push(worker.get());