Uses an open thread handle as the ThreadJoinId on Windows.

runtime/vm/thread_pool.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/thread_pool.h"
 
 #include "vm/dart.h"
 #include "vm/flags.h"
 #include "vm/lockers.h"
 
@@ skipping 194 matching lines @@
       current->all_next_ = worker->all_next_;
       worker->all_next_ = NULL;
       worker->owned_ = false;
       return true;
     }
   }
   return false;
 }
 
 
+void ThreadPool::SetIdleLocked(Worker* worker) {
+  ASSERT(mutex_.IsOwnedByCurrentThread());
+  ASSERT(worker->owned_ && !IsIdle(worker));
+  worker->idle_next_ = idle_workers_;
+  idle_workers_ = worker;
+  count_idle_++;
+  count_running_--;
+}
+
+
 void ThreadPool::SetIdleAndReapExited(Worker* worker) {
   JoinList* list = NULL;
   {
     MutexLocker ml(&mutex_);
     if (shutting_down_) {
       return;
     }
-    ASSERT(worker->owned_ && !IsIdle(worker));
-    worker->idle_next_ = idle_workers_;
-    idle_workers_ = worker;
-    count_idle_++;
-    count_running_--;
-
-    // While we have the lock, opportunistically grab and clear the join_list_.
+    if (join_list_ == NULL) {
+      // Nothing to join, add to the idle list and return.
+      SetIdleLocked(worker);
+      return;
+    }
+    // There is something to join. Grab the join list, drop the lock, do the
+    // join, then grab the lock again and add to the idle list.
     list = join_list_;
     join_list_ = NULL;
   }
   JoinList::Join(&list);
+
+  {
+    MutexLocker ml(&mutex_);
+    if (shutting_down_) {
+      return;
+    }
+    SetIdleLocked(worker);
+  }
 }
 
 
 bool ThreadPool::ReleaseIdleWorker(Worker* worker) {
   MutexLocker ml(&mutex_);
   if (shutting_down_) {
     return false;
   }
   // Remove from idle list.
   if (!RemoveWorkerFromIdleList(worker)) {
     return false;
   }
   // Remove from all list.
   bool found = RemoveWorkerFromAllList(worker);
   ASSERT(found);
 
   // The thread for worker will exit. Add its ThreadId to the join_list_
   // so that we can join on it at the next opportunity.
   OSThread* os_thread = OSThread::Current();
   ASSERT(os_thread != NULL);
-  JoinList::AddLocked(os_thread->join_id(), &join_list_);
+  ThreadJoinId join_id = OSThread::GetCurrentThreadJoinId(os_thread);
+  JoinList::AddLocked(join_id, &join_list_);
   count_stopped_++;
   count_idle_--;
   return true;
 }
 
 
 // Only call while holding the exit_monitor_
 void ThreadPool::AddWorkerToShutdownList(Worker* worker) {
   ASSERT(exit_monitor_.IsOwnedByCurrentThread());
   worker->shutdown_next_ = shutting_down_workers_;
@@ skipping 159 matching lines @@
   ml.Notify();
 }
 
 
 // static
 void ThreadPool::Worker::Main(uword args) {
   Worker* worker = reinterpret_cast<Worker*>(args);
   OSThread* os_thread = OSThread::Current();
   ASSERT(os_thread != NULL);
   ThreadId id = os_thread->id();
-  ThreadJoinId join_id = os_thread->join_id();
   ThreadPool* pool;
 
   // Set the thread's stack_base based on the current stack pointer.
   os_thread->set_stack_base(Thread::GetCurrentStackPointer());
 
   {
     MonitorLocker ml(&worker->monitor_);
     ASSERT(worker->task_);
     worker->id_ = id;
     pool = worker->pool_;
   }
 
   bool released = worker->Loop();
 
   // It should be okay to access these unlocked here in this assert.
   // worker->all_next_ is retained by the pool for shutdown monitoring.
   ASSERT(!worker->owned_ && (worker->idle_next_ == NULL));
 
   if (!released) {
     // This worker is exiting because the thread pool is being shut down.
     // Inform the thread pool that we are exiting. We remove this worker from
     // shutting_down_workers_ list because there will be no need for the
     // ThreadPool to take action for this worker.
+    ThreadJoinId join_id = OSThread::GetCurrentThreadJoinId(os_thread);
     {
       MutexLocker ml(&pool->mutex_);
       JoinList::AddLocked(join_id, &pool->join_list_);
     }
 
     // worker->id_ should never be read again, so set to invalid in debug mode
     // for asserts.
 #if defined(DEBUG)
     {
       MonitorLocker ml(&worker->monitor_);
@@ skipping 19 matching lines @@
   }
 
   // Call the thread exit hook here to notify the embedder that the
   // thread pool thread is exiting.
   if (Dart::thread_exit_callback() != NULL) {
     (*Dart::thread_exit_callback())();
   }
 }
 
 }  // namespace dart