src: reduce platform worker barrier lifetime

Minor cleanup in the lifetime for the platform worker initialization
synchronization barrier.

PR-URL: #23419
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

src/node_platform.cc

@@ -167,17 +167,20 @@ class WorkerThreadsTaskRunner::DelayedTaskScheduler {
 };
 
 WorkerThreadsTaskRunner::WorkerThreadsTaskRunner(int thread_pool_size) {
- Mutex::ScopedLock lock(platform_workers_mutex_);
- pending_platform_workers_ = thread_pool_size;
+ Mutex platform_workers_mutex;
+ ConditionVariable platform_workers_ready;
+
+ Mutex::ScopedLock lock(platform_workers_mutex);
+ int pending_platform_workers = thread_pool_size;
 
  delayed_task_scheduler_.reset(
  new DelayedTaskScheduler(&pending_worker_tasks_));
  threads_.push_back(delayed_task_scheduler_->Start());
 
  for (int i = 0; i < thread_pool_size; i++) {
  PlatformWorkerData* worker_data = new PlatformWorkerData{
- &pending_worker_tasks_, &platform_workers_mutex_,
- &platform_workers_ready_, &pending_platform_workers_, i
+ &pending_worker_tasks_, &platform_workers_mutex,
+ &platform_workers_ready, &pending_platform_workers, i
  };
  std::unique_ptr<uv_thread_t> t { new uv_thread_t() };
  if (uv_thread_create(t.get(), PlatformWorkerThread,
@@ -189,8 +192,8 @@ WorkerThreadsTaskRunner::WorkerThreadsTaskRunner(int thread_pool_size) {
 
  // Wait for platform workers to initialize before continuing with the
  // bootstrap.
- while (pending_platform_workers_ > 0) {
- platform_workers_ready_.Wait(lock);
+ while (pending_platform_workers > 0) {
+ platform_workers_ready.Wait(lock);
  }
 }
 

src/node_platform.h

@@ -117,10 +117,6 @@ class WorkerThreadsTaskRunner {
  std::unique_ptr<DelayedTaskScheduler> delayed_task_scheduler_;
 
  std::vector<std::unique_ptr<uv_thread_t>> threads_;
-
- Mutex platform_workers_mutex_;
- ConditionVariable platform_workers_ready_;
- int pending_platform_workers_;
 };
 
 class NodePlatform : public MultiIsolatePlatform {